From e0033d3989d11d54d89bc9d2fcfe0822102c5bac Mon Sep 17 00:00:00 2001
From: aiongg <aiongtaigi@gmail.com>
Date: Mon, 26 Oct 2026 18:18:15 +0000
Subject: [PATCH] refactor(export): move lib.rs's tests to tests.rs

---
 crates/export/src/lib.rs   | 783 +------------------------------------
 crates/export/src/tests.rs | 780 ++++++++++++++++++++++++++++++++++++
 2 files changed, 781 insertions(+), 782 deletions(-)
 create mode 100644 crates/export/src/tests.rs

diff --git a/crates/export/src/lib.rs b/crates/export/src/lib.rs
index a9c43fb42..dac5ec517 100644
--- a/crates/export/src/lib.rs
+++ b/crates/export/src/lib.rs
@@ -1066,785 +1066,4 @@ pub fn rtf(pages: &[Page]) -> String {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// A page of `n` one-word blocks, each in its own size and colour.
-    fn varied_page(n: usize) -> Page {
-        let blocks = (0..n)
-            .map(|i| Block {
-                text: "word".into(),
-                rect: [72.0, i as f64, 100.0, i as f64 + 1.0],
-                size: 4.0 + i as f64 * 0.5,
-                bold: false,
-                italic: false,
-                color: [(i % 256) as f64 / 255.0, (i / 256 % 256) as f64 / 255.0, 0.5],
-                rotation: 0.0,
-                space_around: [false; 2],
-            })
-            .collect();
-        Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None }
-    }
-
-    fn lookup_steps(f: impl FnOnce()) -> usize {
-        LOOKUP_STEPS.with(|c| c.set(0));
-        f();
-        LOOKUP_STEPS.with(|c| c.get())
-    }
-
-    #[test]
-    fn many_distinct_sizes_are_counted_in_constant_steps_each() {
-        let pages = [varied_page(3000)];
-        let steps = lookup_steps(|| {
-            body_size(&pages);
-        });
-        assert!(steps <= 2 * 3000, "{steps} steps");
-    }
-
-    #[test]
-    fn many_distinct_colours_take_constant_steps_each() {
-        let pages = [varied_page(3000)];
-        let mut out = String::new();
-        let steps = lookup_steps(|| out = rtf(&pages));
-        assert!(steps <= 4 * 3000, "{steps} steps");
-        assert!(out.contains("\\cf3000 ") || out.contains("\\cf3000\\"), "the last colour has the last slot");
-    }
-
-    fn page() -> Page {
-        let b = |t: &str, y: f64, size: f64, bold: bool| Block {
-            text: t.into(),
-            rect: [72.0, y, 500.0, y + size],
-            size,
-            bold,
-            italic: false,
-            color: [0.0; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        };
-        Page {
-            width: 612.0,
-            height: 792.0,
-            blocks: vec![
-                b("Body text after the picture, which is long enough to be the main text size of the page.", 400.0, 11.0, false),
-                b("Annual Report", 700.0, 24.0, true),
-                b("Overview", 650.0, 14.0, true),
-                b("Some <body> text & more of it so that eleven points is the body size here.", 620.0, 11.0, false),
-            ],
-            images: vec![Image {
-                ext: "png",
-                bytes: b"\x89PNG\r\n\x1a\n\0\0\0\rIHDR\0\0\0\x02\0\0\0\x03".as_slice().into(),
-                rect: [72.0, 450.0, 272.0, 600.0],
-                size: [200.0, 150.0],
-                rotation: 0.0,
-            }],
-            background: None,
-        }
-    }
-
-    #[test]
-    fn html_has_headings_paragraphs_and_images_in_order() {
-        let h = html(&[page(), page()], "Report");
-        let order: Vec<usize> = ["<h1>Annual Report</h1>", "<h2>Overview</h2>", "<p>Some &lt;body&gt; text &amp;", "<img", "<p>Body text after"]
-            .iter()
-            .map(|x| h.find(x).unwrap_or_else(|| panic!("{x} missing in {h}")))
-            .collect();
-        assert!(order.windows(2).all(|w| w[0] < w[1]), "{order:?}");
-        assert_eq!(h.matches("<hr>").count(), 1);
-        assert_eq!(base64(b"Man"), "TWFu");
-        assert_eq!(base64(b"Ma"), "TWE=");
-    }
-
-    #[test]
-    fn docx_is_a_word_package() {
-        let d = docx(&[page()], "Report");
-        assert!(d.starts_with(b"PK"));
-        let names: Vec<&str> =
-            ["[Content_Types].xml", "word/document.xml", "word/styles.xml", "word/_rels/document.xml.rels", "word/media/image1.png", "_rels/.rels"]
-                .to_vec();
-        for n in names {
-            assert!(d.windows(n.len()).any(|w| w == n.as_bytes()), "{n}");
-        }
-    }
-
-    #[test]
-    fn word_does_not_invent_borders_for_aligned_invoice_fields() {
-        let xml = part(&docx(&[table_page()], "Invoice"), "word/document.xml");
-        assert!(xml.contains("<w:tbl>"));
-        assert!(!xml.contains("w:val=\"single\""), "text alignment is not evidence of a border: {xml}");
-        assert!(xml.contains("<w:insideH w:val=\"nil\"/>"));
-    }
-
-    #[test]
-    fn word_table_cell_widths_follow_the_columns_they_span() {
-        let cell = |text: &str, span| Cell { text: text.into(), size: 11.0, bold: false, italic: false, color: [0.0; 3], span };
-        let table = Table {
-            rect: [0.0, 0.0, 300.0, 100.0],
-            cols: vec![0.0, 50.0, 150.0],
-            rows: vec![
-                vec![cell("First", 1), cell("Second", 1), cell("Third", 1)],
-                vec![cell("First", 1), cell("Last two", 2)],
-                vec![cell("First two", 2), cell("Third", 1)],
-                vec![cell("All", 3)],
-                vec![cell("First", 1)],
-            ],
-        };
-        let xml = docx_table(&table);
-        assert!(xml.contains("<w:gridCol w:w=\"1000\"/><w:gridCol w:w=\"2000\"/><w:gridCol w:w=\"3000\"/>"), "{xml}");
-        let widths: Vec<Vec<&str>> =
-            xml.split("<w:tr>").skip(1).map(|row| row.split("<w:tcW w:w=\"").skip(1).map(|cell| cell.split('"').next().unwrap()).collect()).collect();
-        assert_eq!(widths, vec![vec!["1000", "2000", "3000"], vec!["1000", "5000"], vec!["3000", "3000"], vec!["6000"], vec!["1000", "0", "0"]]);
-    }
-
-    #[test]
-    fn word_keeps_a_page_with_a_clear_image_and_big_title_in_flow() {
-        // page() has a picture between paragraphs and a 24 pt title over 11 pt body text, but
-        // nothing overlaps: it must stay flowing paragraphs with the image inline.
-        let xml = part(&docx(&[page()], "Report"), "word/document.xml");
-        assert!(!xml.contains("position:absolute"), "nothing overlaps, so nothing floats: {xml}");
-        assert!(xml.contains("<wp:inline>"), "the picture stays inline: {xml}");
-        assert!(xml.contains("<w:pStyle w:val=\"Heading1\"/>"), "the title stays a heading: {xml}");
-        let (title, body) = (xml.find(">Annual Report</w:t>"), xml.find(">Body text after the picture"));
-        assert!(title.is_some() && body.is_some() && title < body, "reading order kept: {xml}");
-        // The same page with the picture moved over the body text floats.
-        let mut over = page();
-        over.images[0].rect = [72.0, 380.0, 272.0, 530.0];
-        let xml = part(&docx(&[over], "Report"), "word/document.xml");
-        assert!(xml.contains("position:absolute"), "an image over text floats: {xml}");
-    }
-
-    #[test]
-    fn word_overlap_does_not_consume_invoice_body_space() {
-        let mut p = table_page();
-        p.blocks.push(Block {
-            text: "DRAFT".into(),
-            rect: [100.0, 200.0, 500.0, 700.0],
-            size: 100.0,
-            bold: false,
-            italic: false,
-            color: [0.8; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        });
-        p.images = page().images;
-        let xml = part(&docx(&[p], "Invoice"), "word/document.xml");
-        assert!(xml.contains("position:absolute"), "overlapping text must float: {xml}");
-        assert!(!xml.contains("<wp:inline>"), "images must not displace invoice text");
-        assert!(!xml.contains("<w:tbl>"), "the source text boxes must keep their positions");
-        assert_eq!(xml.matches(">DRAFT</w:t>").count(), 1);
-        assert_eq!(xml.matches("w:type=\"page\"").count(), 0);
-        assert!(xml.contains("margin-left:72.000pt;margin-top:160.000pt"), "Meter field keeps its source position: {xml}");
-        let watermark = xml.split(">DRAFT</w:t>").next().unwrap().rsplit("<v:rect ").next().unwrap();
-        assert!(watermark.contains("z-index:-2"), "watermark is behind foreground graphics");
-        // The picture is a DrawingML anchor behind the text (a VML rectangle shows no picture in Word).
-        assert!(!xml.contains("<v:imagedata"), "{xml}");
-        assert!(xml.contains("<wp:anchor ") && xml.contains("behindDoc=\"1\"") && xml.contains("<a:blip r:embed=\"rIdImg1\"/>"), "{xml}");
-    }
-
-    #[test]
-    fn word_rotated_pages_keep_separate_page_sizes_and_unique_shapes() {
-        let mut p = table_page();
-        p.blocks[0].rotation = 45.0;
-        let mut second = p.clone();
-        second.width = 400.0;
-        second.height = 500.0;
-        let xml = part(&docx(&[p, second], "Two invoices"), "word/document.xml");
-        assert!(xml.contains("rotation:315.000"), "PDF y-up becomes Word y-down");
-        assert_eq!(xml.matches("<w:sectPr>").count(), 2);
-        assert!(xml.contains("<w:pgSz w:w=\"8000\" w:h=\"10000\"/>"));
-        assert_eq!(xml.matches("id=\"Text1\"").count(), 1);
-        assert_eq!(xml.matches(">Meter</w:t>").count(), 2);
-    }
-
-    /// #2992: pages that share a background colour get it as the Word document's page colour
-    /// (with the setting that makes Word show it); differing or white backgrounds don't.
-    #[test]
-    fn docx_keeps_a_shared_page_background() {
-        let teal = Page { background: Some([0.0, 0.5, 0.5]), ..page() };
-        let zip = docx(&[teal.clone(), teal.clone()], "Teal");
-        let xml = part(&zip, "word/document.xml");
-        assert!(xml.contains("<w:background w:color=\"008080\"/><w:body>"), "{xml}");
-        assert!(part(&zip, "word/settings.xml").contains("<w:displayBackgroundShape/>"));
-        assert!(part(&zip, "[Content_Types].xml").contains("/word/settings.xml"));
-        assert!(part(&zip, "word/_rels/document.xml.rels").contains("Target=\"settings.xml\""));
-        let other = Page { background: Some([1.0, 0.0, 0.0]), ..page() };
-        for (pages, why) in [
-            (vec![teal.clone(), other], "different colours"),
-            (vec![teal.clone(), page()], "a page without one"),
-            (vec![Page { background: Some([1.0; 3]), ..page() }], "white"),
-            (vec![page()], "none"),
-        ] {
-            let zip = docx(&pages, "Plain");
-            assert!(!part(&zip, "word/document.xml").contains("<w:background"), "{why}");
-            assert!(!zip.windows(b"word/settings.xml".len()).any(|w| w == b"word/settings.xml"), "{why}");
-        }
-    }
-
-    /// One part of a package written by [`Zip`], inflated.
-    pub(crate) fn part(zip: &[u8], name: &str) -> String {
-        let at = |i: usize, n: usize| zip[i..i + n].iter().rev().fold(0usize, |v, b| v << 8 | *b as usize);
-        let mut i = 0;
-        while zip[i..].starts_with(b"PK\x03\x04") {
-            let (size, name_len) = (at(i + 18, 4), at(i + 26, 2));
-            let data = i + 30 + name_len;
-            if &zip[i + 30..data] == name.as_bytes() {
-                let mut s = String::new();
-                std::io::Read::read_to_string(&mut flate2::read::DeflateDecoder::new(&zip[data..data + size]), &mut s).unwrap();
-                return s;
-            }
-            i = data + size;
-        }
-        panic!("{name} missing")
-    }
-
-    #[test]
-    fn word_opens_text_with_control_characters_and_long_pages() {
-        // #72: text extracted without a usable /ToUnicode holds C0 controls, which XML forbids;
-        // Word then refused the whole file. A till receipt is also taller than Word's 22 in.
-        let mut p = page();
-        p.height = 2400.0;
-        p.blocks.push(Block {
-            text: "Total\u{0}\u{3}\u{c} 4.50\u{FFFF}\tGBP".into(),
-            rect: [72.0, 100.0, 300.0, 110.0],
-            size: f64::NAN,
-            bold: false,
-            italic: false,
-            color: [0.0; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        });
-        let xml = part(&docx(&[p.clone()], "Receipt\u{1}"), "word/document.xml");
-        assert!(xml.contains(">Total 4.50\tGBP</w:t>"), "{xml}");
-        assert!(!xml.chars().any(|c| !allowed(c)));
-        assert!(xml.contains("<w:pgSz w:w=\"12240\" w:h=\"31680\"/>"), "clamped to 22 in: {xml}");
-        assert!(xml.contains("<w:sz w:val=\"24\"/>"), "a non-finite size falls back to 12 pt");
-        assert!(rtf(&[p]).contains("Total 4.50\tGBP"));
-        // A narrow page keeps room for text: margins shrink.
-        let narrow = Page { width: 100.0, height: 200.0, ..page() };
-        let xml = part(&docx(&[narrow], "Narrow"), "word/document.xml");
-        assert!(xml.contains("<w:pgMar w:top=\"500\" w:right=\"250\" w:bottom=\"500\" w:left=\"250\""), "{xml}");
-    }
-
-    #[test]
-    fn text_colour_survives_every_format() {
-        // #526: a dark green heading (0.05 0.23 0.18 rg) came out black in Word.
-        let mut p = page();
-        p.blocks[1].color = [0.05, 0.23, 0.18];
-        p.blocks[3].color = [f64::NAN, 2.0, -1.0];
-        let xml = part(&docx(&[p.clone()], "Colour"), "word/document.xml");
-        assert!(xml.contains("<w:color w:val=\"0D3B2E\"/>"), "{xml}");
-        assert!(xml.contains("<w:color w:val=\"00FF00\"/>"), "out-of-range values clamp: {xml}");
-        // Black text keeps Word's default colour.
-        assert_eq!(xml.matches("<w:color ").count(), 2, "{xml}");
-        let h = html(&[p.clone()], "Colour");
-        assert!(h.contains("<h1 style=\"color:#0D3B2E\">Annual Report</h1>"), "{h}");
-        assert!(h.contains("<p style=\"color:#00FF00\">"), "{h}");
-        let r = rtf(&[p.clone()]);
-        assert!(r.contains("{\\colortbl;\\red13\\green59\\blue46;\\red0\\green255\\blue0;}"), "{r}");
-        assert!(r.contains("\\cf1 Annual Report"), "{r}");
-        let ppt = pptx(&[p], "Colour");
-        let pxml = part(&ppt, "ppt/slides/slide1.xml");
-        assert!(pxml.contains("<a:srgbClr val=\"0D3B2E\"/>"), "{pxml}");
-        assert!(pxml.contains("<a:srgbClr val=\"00FF00\"/>"), "out-of-range values clamp: {pxml}");
-        // A table cell keeps its colour too.
-        let mut t = table_page();
-        t.blocks[0].color = [1.0, 0.0, 0.0];
-        let xml = part(&docx(&[t.clone()], "Grid"), "word/document.xml");
-        assert!(xml.contains("<w:color w:val=\"FF0000\"/>"), "{xml}");
-        assert!(html(&[t], "Grid").contains("style=\"color:#FF0000\""));
-    }
-
-    #[test]
-    fn rtf_escapes_and_sizes() {
-        let mut p = page();
-        p.blocks.push(Block {
-            text: "Café {x}".into(),
-            rect: [72.0, 100.0, 200.0, 110.0],
-            size: 10.0,
-            bold: false,
-            italic: true,
-            color: [0.0; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        });
-        let r = rtf(&[p]);
-        assert!(r.starts_with("{\\rtf1") && r.ends_with('}'));
-        assert!(r.contains("\\fs48\\b Annual Report"));
-        assert!(r.contains("\\fs20\\i Caf\\u233? \\{x\\}"), "{r}");
-    }
-
-    /// A 3-column table with a spanning header row and a hole in the last row.
-    fn table_page() -> Page {
-        let cell = |t: &str, x: f64, y: f64, w: f64| Block {
-            text: t.into(),
-            rect: [x, y, x + w, y + 12.0],
-            size: 11.0,
-            bold: false,
-            italic: false,
-            color: [0.0; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        };
-        Page {
-            width: 612.0,
-            height: 792.0,
-            blocks: vec![
-                cell("Meter", 72.0, 620.0, 120.0),
-                cell("Unit", 232.0, 620.0, 80.0),
-                cell("Reading", 392.0, 620.0, 100.0),
-                cell("A1", 72.0, 590.0, 120.0),
-                cell("kWh", 232.0, 590.0, 80.0),
-                cell("37414.00", 392.0, 590.0, 100.0),
-                cell("A2", 72.0, 560.0, 120.0),
-                cell("kW", 232.0, 560.0, 80.0),
-                // A2's row is missing its third cell (an empty cell in the grid).
-                cell("Totals", 72.0, 530.0, 240.0),
-                Block {
-                    text: "Notes follow the table and are long enough to be the body text size of the page here.".into(),
-                    rect: [72.0, 460.0, 500.0, 471.0],
-                    size: 11.0,
-                    bold: false,
-                    italic: false,
-                    color: [0.0; 3],
-                    rotation: 0.0,
-                    space_around: [false; 2],
-                },
-            ],
-            images: Vec::new(),
-            background: None,
-        }
-    }
-
-    #[test]
-    fn grid_text_becomes_a_real_table_in_every_format() {
-        let p = table_page();
-        let h = html(std::slice::from_ref(&p), "Bill");
-        assert!(h.contains("<table>"), "{h}");
-        assert!(h.contains("<td colspan=\"2\">Totals</td>"), "spanning cell: {h}");
-        assert_eq!(h.matches("<tr>").count(), 4, "{h}");
-        assert!(h.contains("<td></td>"), "the hole is an empty cell: {h}");
-        assert!(h.contains("<p>Notes follow"), "the paragraph after the table stays: {h}");
-
-        let d = docx(std::slice::from_ref(&p), "Bill");
-        assert!(d.starts_with(b"PK"));
-        assert!(d.windows(b"word/document.xml".len()).any(|w| w == b"word/document.xml"));
-        let (tables, _) = tables(&p.blocks);
-        assert_eq!(tables.len(), 1);
-        let table_xml = docx_table(&tables[0]);
-        assert!(table_xml.contains("<w:tblGrid>"));
-        assert!(table_xml.contains("<w:gridSpan w:val=\"2\"/>"), "{table_xml}");
-        assert_eq!(table_xml.matches("<w:tr>").count(), 4);
-
-        let r = rtf(std::slice::from_ref(&p));
-        assert!(r.contains("\\trowd"), "{r}");
-        assert_eq!(r.matches("\\row").count(), 4);
-        // Boundaries precede the cells; "Totals" spans two columns, so it ends at the third edge.
-        assert!(r.contains("\\trowd\\trgaph108\\cellx4640\\cellx7840\\cellx9920{"), "{r}");
-        assert!(r.contains("\\trowd\\trgaph108\\cellx7840{\\intbl\\fs22 Totals}\\cell\\row"), "{r}");
-
-        let pt = pptx(std::slice::from_ref(&p), "Bill");
-        assert!(pt.starts_with(b"PK"));
-        assert!(pt.windows(b"ppt/slides/slide1.xml".len()).any(|w| w == b"ppt/slides/slide1.xml"));
-        let slide_xml = part(&pt, "ppt/slides/slide1.xml");
-        assert!(slide_xml.contains("<a:tbl>"));
-        assert!(slide_xml.contains("gridSpan=\"2\""));
-        assert_eq!(slide_xml.matches("<a:tr ").count(), 4);
-    }
-
-    #[test]
-    fn a_staircase_of_blocks_is_not_a_huge_table() {
-        // Row k holds blocks in columns k and k + 1: every column has two members and every row
-        // two columns, so without a cap this would be one table of (n / 2)² cells.
-        let n = 4000;
-        let blocks: Vec<Block> = (0..n)
-            .map(|i| {
-                let (row, col) = (i / 2, i / 2 + i % 2);
-                let (x, y) = (10.0 + col as f64 * 20.0, 10_000.0 - row as f64 * 14.0);
-                Block {
-                    text: "x".into(),
-                    rect: [x, y, x + 8.0, y + 12.0],
-                    size: 11.0,
-                    bold: false,
-                    italic: false,
-                    color: [0.0; 3],
-                    rotation: 0.0,
-                    space_around: [false; 2],
-                }
-            })
-            .collect();
-        let started = std::time::Instant::now();
-        let (tables, _) = tables(&blocks);
-        assert!(tables.iter().all(|t| t.cols.len() <= MAX_COLS), "{} columns", tables.iter().map(|t| t.cols.len()).max().unwrap_or(0));
-        assert!(started.elapsed() < std::time::Duration::from_secs(5), "took {:?}", started.elapsed());
-    }
-
-    #[test]
-    fn word_opens_tables_up_to_its_column_limit() {
-        // Rows of short numbers on a regular grid, n columns wide.
-        let grid = |n: usize| Page {
-            width: 1500.0,
-            height: 792.0,
-            blocks: (0..3)
-                .flat_map(|row| {
-                    (0..n).map(move |col| {
-                        let (x, y) = (20.0 + col as f64 * 22.0, 700.0 - row as f64 * 14.0);
-                        Block {
-                            text: (col + 1).to_string(),
-                            rect: [x, y, x + 8.0, y + 8.0],
-                            size: 8.0,
-                            bold: false,
-                            italic: false,
-                            color: [0.0; 3],
-                            rotation: 0.0,
-                            space_around: [false; 2],
-                        }
-                    })
-                })
-                .collect(),
-            images: Vec::new(),
-            background: None,
-        };
-        let grid_cols = |p: &Page| part(&docx(std::slice::from_ref(p), "Grid"), "word/document.xml").matches("<w:gridCol ").count();
-        assert_eq!(grid_cols(&grid(63)), 63, "63 columns is still a table");
-        // Word refuses to open a document with a 64-column table, so that grid stays text.
-        assert_eq!(grid_cols(&grid(64)), 0);
-    }
-
-    fn block(t: &str, x0: f64, y0: f64, x1: f64, y1: f64) -> Block {
-        Block {
-            text: t.into(),
-            rect: [x0, y0, x1, y1],
-            size: 12.0,
-            bold: false,
-            italic: false,
-            color: [0.0; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        }
-    }
-
-    /// #2806: a sentence whose link is set in another colour or font runs on as separate blocks
-    /// on one line. They are not table columns, even when several such lines share left edges.
-    #[test]
-    fn a_link_inside_a_sentence_is_not_a_table_column() {
-        let blue = |t: &str, x0: f64, y0: f64, x1: f64, y1: f64| Block { color: [0.02, 0.388, 0.757], ..block(t, x0, y0, x1, y1) };
-        let p = Page {
-            width: 612.0,
-            height: 792.0,
-            blocks: vec![
-                block("6.3. 2. All content shown at", 121.7, 710.3, 272.0, 724.9),
-                blue("http", 273.5, 710.3, 294.1, 724.9),
-                blue("s", 294.1, 709.8, 298.8, 725.8),
-                blue("://women", 298.8, 710.3, 348.0, 724.9),
-                blue("g", 348.1, 709.8, 353.7, 725.8),
-                blue("randprix.fide.com", 353.7, 710.3, 443.2, 724.9),
-                block("shall be reviewed and approved by the Press Officer.", 164.3, 622.5, 533.1, 724.9),
-                block("6.3. 3. The Organiser shall warrant that", 121.7, 601.8, 345.1, 616.5),
-                blue("https://womengrandprix.fide.com", 350.2, 601.3, 519.9, 617.4),
-                block("is managed in a professional way and furthermore that it is capable of", 164.3, 557.9, 533.0, 616.5),
-                block("6. 3. 4. The Press Officer shall report to the FIDE Head of PR.", 121.7, 516.6, 530.3, 551.9),
-                block("conducted during a WGP tournament.", 164.3, 502.0, 352.5, 516.6),
-            ],
-            images: Vec::new(),
-            background: None,
-        };
-        let h = html(std::slice::from_ref(&p), "Regulations");
-        assert!(!h.contains("<table>"), "running text became a table: {h}");
-        // The link is a run of its sentence, in its own colour (#4158).
-        assert!(h.contains("<p>6.3. 2. All content shown at <span style=\"color:#0563C1\">http</span>"), "{h}");
-        for b in &p.blocks {
-            assert!(h.contains(&b.text), "{} was lost: {h}", b.text);
-        }
-    }
-
-    /// #2806: lines that each run on into a link starting at the same place are sentences, not a
-    /// two-column table, even three in a row.
-    #[test]
-    fn sentences_that_run_on_into_links_are_not_a_table() {
-        let blue = |t: &str, x0: f64, y0: f64, x1: f64, y1: f64| Block { color: [0.02, 0.388, 0.757], ..block(t, x0, y0, x1, y1) };
-        let mut blocks = Vec::new();
-        for (n, lead) in ["Rules are published at", "Pairings are posted at", "Results are listed at"].iter().enumerate() {
-            let y = 700.0 - 16.0 * n as f64;
-            blocks.push(block(lead, 72.0, y, 211.0, y + 12.0));
-            blocks.push(blue("https://example.org/event", 212.5, y, 360.0, y + 12.0));
-        }
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let h = html(std::slice::from_ref(&p), "Event");
-        assert!(!h.contains("<table>"), "sentences became a table: {h}");
-        assert_eq!(h.matches("https://example.org/event").count(), 3, "{h}");
-    }
-
-    /// A continuation can drift into a grid column covered by the preceding cell's span.
-    /// It must remain available as paragraph text if that slot never becomes an output cell.
-    #[test]
-    fn table_spans_do_not_consume_text_they_do_not_emit() {
-        let mut blocks = vec![
-            Block { size: 12.0, ..block("ABCDEFGHIJK", 72.1, 697.0, 151.3, 710.8) },
-            Block { size: 12.0, color: [0.0, 0.0, 1.0], ..block("LOST", 150.4, 697.0, 179.2, 710.8) },
-            Block { size: 12.0, ..block("R0", 250.0, 697.0, 264.4, 710.8) },
-        ];
-        for row in 1..=4 {
-            let y = 697.0 - f64::from(row) * 50.0;
-            for (text, left, right) in [(format!("L{row}"), 72.1, 86.5), (format!("M{row}"), 146.4, 160.8), (format!("R{row}"), 250.0, 264.4)] {
-                blocks.push(Block { size: 12.0, ..block(&text, left, y, right, y + 13.8) });
-            }
-        }
-        let p = Page { width: 612.0, height: 792.0, blocks, ..Page::default() };
-        let (tables, consumed) = tables(&p.blocks);
-        assert_eq!(tables.len(), 1);
-        assert_eq!(tables[0].rows[0][0].span, 2);
-        assert!(!consumed[1], "a covered slot did not emit its text");
-        assert!(consumed.iter().enumerate().all(|(index, used)| index == 1 || *used));
-        let outputs = [
-            html(std::slice::from_ref(&p), "Continuations"),
-            part(&docx(std::slice::from_ref(&p), "Continuations"), "word/document.xml"),
-            rtf(std::slice::from_ref(&p)),
-            part(&pptx(std::slice::from_ref(&p), "Continuations"), "ppt/slides/slide1.xml"),
-        ];
-        for output in outputs {
-            for b in &p.blocks {
-                assert_eq!(output.matches(&b.text).count(), 1, "{} must survive exactly once", b.text);
-            }
-        }
-    }
-
-    /// #2806: a superscript right after a number ("1" "st") continues its cell; the prize table
-    /// around it stays a table.
-    #[test]
-    fn a_superscript_beside_a_number_keeps_its_table() {
-        let mut blocks = vec![block("PLACE", 100.0, 700.0, 140.0, 712.0), block("PRIZE (euros)", 300.0, 700.0, 380.0, 712.0)];
-        for (n, (row, sup)) in [("1", "st"), ("2", "nd"), ("3", "rd"), ("4", "th")].iter().enumerate() {
-            let y = 680.0 - 20.0 * n as f64;
-            blocks.push(block(row, 100.0, y, 106.0, y + 12.0));
-            blocks.push(Block { size: 8.0, ..block(sup, 106.0, y + 5.0, 113.0, y + 13.0) });
-            blocks.push(block(&format!("{},000", 30 - 5 * n), 300.0, y, 340.0, y + 12.0));
-        }
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let h = html(std::slice::from_ref(&p), "Prizes");
-        assert!(h.contains("<table>"), "the prize table was lost: {h}");
-        assert!(h.contains("30,000") && h.contains("15,000"), "{h}");
-        let (tables, consumed) = tables(&p.blocks);
-        assert!(consumed.iter().all(|used| *used), "ordinary table continuations stay in their cells");
-        let cells: Vec<&str> = tables.iter().flat_map(|t| &t.rows).flatten().map(|c| c.text.as_str()).collect();
-        assert!(["st", "nd", "rd", "th"].iter().all(|suffix| cells.contains(suffix)));
-    }
-
-    #[test]
-    fn two_column_body_text_is_not_mistaken_for_a_table() {
-        let para = |t: &str, x: f64, y: f64| Block {
-            text: t.into(),
-            rect: [x, y, x + 200.0, y + 90.0], // nine lines tall: body text, not a cell
-            size: 11.0,
-            bold: false,
-            italic: false,
-            color: [0.0; 3],
-            rotation: 0.0,
-            space_around: [false; 2],
-        };
-        let p = Page {
-            width: 612.0,
-            height: 792.0,
-            blocks: vec![
-                para("Left column text of the page, long enough to be a flowing paragraph.", 72.0, 500.0),
-                para("Right column text of the page, long enough to be a flowing paragraph.", 320.0, 500.0),
-                para("Second left block, still a tall flowing paragraph rather than a cell.", 72.0, 400.0),
-                para("Second right block, still a tall flowing paragraph rather than a cell.", 320.0, 400.0),
-            ],
-            images: Vec::new(),
-            background: None,
-        };
-        let h = html(&[p], "Paper");
-        assert!(!h.contains("<table>"), "tall two-column text must stay paragraphs: {h}");
-    }
-
-    /// #1936: every picture Word is told to draw (`r:embed`) names a relationship whose target is a
-    /// file in the package, with a content type; JPEG pictures too, inline or placed.
-    #[test]
-    fn word_pictures_resolve_to_media_in_the_package() {
-        let jpeg = Image { ext: "jpg", bytes: [0xFF, 0xD8, 0xFF, 0xD9].as_slice().into(), ..page().images[0].clone() };
-        for placed in [false, true] {
-            let mut p = page();
-            p.images = vec![jpeg.clone()];
-            if placed {
-                p.images[0].rect = [72.0, 640.0, 272.0, 790.0];
-                p.blocks[0].rect = [72.0, 700.0, 300.0, 760.0];
-            }
-            let zip = docx(&[p], "T");
-            let xml = part(&zip, "word/document.xml");
-            assert_eq!(xml.contains("<wp:anchor "), placed, "{xml}");
-            let rels = part(&zip, "word/_rels/document.xml.rels");
-            let embed = xml.split("r:embed=\"").nth(1).and_then(|r| r.split('"').next()).unwrap();
-            let rel = rels.split(&format!("Id=\"{embed}\"")).nth(1).unwrap();
-            assert!(rel.contains("relationships/image\""), "{rels}");
-            let target = rel.split("Target=\"").nth(1).and_then(|t| t.split('"').next()).unwrap();
-            assert_eq!(target, "media/image1.jpg");
-            assert!(zip.windows(21).any(|w| w == b"word/media/image1.jpg"));
-            assert!(part(&zip, "[Content_Types].xml").contains("Extension=\"jpg\" ContentType=\"image/jpeg\""));
-            assert!(xml.matches("<wp:docPr ").count() == 1 && !xml.contains("<v:imagedata"));
-        }
-    }
-
-    #[test]
-    fn word_export_bounds_the_number_of_pictures_and_skips_empty_ones() {
-        let mut p = page();
-        let one = p.images[0].clone();
-        p.images = vec![Image { bytes: [].as_slice().into(), ..one.clone() }];
-        p.images.extend(std::iter::repeat_n(one, MAX_MEDIA + 10));
-        let zip = docx(&[p], "T");
-        let rels = part(&zip, "word/_rels/document.xml.rels");
-        assert_eq!(rels.matches("relationships/image\"").count(), MAX_MEDIA);
-    }
-
-    /// The flowing paragraphs of a Word document (table cells left out), each as its runs' text
-    /// and whether the run is italic.
-    fn word_paragraphs(xml: &str) -> Vec<Vec<(String, bool)>> {
-        let body = xml.split("<w:tbl>").map(|s| s.split_once("</w:tbl>").map_or(s, |(_, after)| after)).collect::<String>();
-        body.split("<w:p>")
-            .skip(1)
-            .map(|p| {
-                let p = p.split_once("</w:p>").map_or(p, |(inside, _)| inside);
-                p.split("<w:r>")
-                    .skip(1)
-                    .filter_map(|r| {
-                        let text = r.split_once("<w:t xml:space=\"preserve\">")?.1.split_once("</w:t>")?.0;
-                        Some((text.to_string(), r.contains("<w:i/>")))
-                    })
-                    .collect::<Vec<_>>()
-            })
-            .filter(|runs| !runs.is_empty())
-            .collect()
-    }
-
-    fn runs(r: &[(&str, bool)]) -> Vec<(String, bool)> {
-        r.iter().map(|(t, i)| (t.to_string(), *i)).collect()
-    }
-
-    /// "Before *Chevron* after." on one line: the roman text, the italic case name and the roman
-    /// text after it, the way reading blocks split a sentence at its style changes (#4158). The
-    /// italic face stands a little taller than the roman one around it.
-    fn italic_sentence() -> Vec<Block> {
-        vec![
-            block("Before", 72.0, 700.0, 110.0, 712.0),
-            Block { italic: true, ..block("Chevron", 113.0, 700.0, 158.0, 712.6) },
-            block("after.", 161.0, 700.0, 190.0, 712.0),
-        ]
-    }
-
-    /// #4158: a run in another style inside a sentence stays in that sentence's paragraph, as a
-    /// run in its own style, in every Office format.
-    #[test]
-    fn an_italic_word_stays_in_its_sentence() {
-        let mut blocks = italic_sentence();
-        blocks.push(block("The next line is a paragraph of its own.", 72.0, 684.0, 300.0, 696.0));
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let xml = part(&docx(std::slice::from_ref(&p), "Opinion"), "word/document.xml");
-        assert_eq!(
-            word_paragraphs(&xml),
-            vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)]), runs(&[("The next line is a paragraph of its own.", false)])],
-            "{xml}"
-        );
-        let h = html(std::slice::from_ref(&p), "Opinion");
-        assert!(h.contains("<p>Before <em>Chevron </em>after.</p>"), "{h}");
-        let r = rtf(std::slice::from_ref(&p));
-        assert!(r.contains("{\\pard\\fs24 Before {\\fs24\\b0\\i\\cf0 Chevron }{\\fs24\\b0\\i0\\cf0 after.}\\par}"), "{r}");
-        // The longest line is the slide's title; the sentence is one paragraph of the body.
-        let pxml = part(&pptx(std::slice::from_ref(&p), "Opinion"), "ppt/slides/slide1.xml");
-        assert!(
-            pxml.contains("<a:p><a:r><a:rPr sz=\"1200\"></a:rPr><a:t>Before </a:t></a:r><a:r><a:rPr sz=\"1200\" i=\"1\"></a:rPr><a:t>Chevron </a:t></a:r><a:r><a:rPr sz=\"1200\"></a:rPr><a:t>after.</a:t></a:r></a:p>"),
-            "{pxml}"
-        );
-    }
-
-    /// #4158: the runs keep their order along the line whatever order the blocks come in, and the
-    /// paragraph keeps its place on the page, though the italic run stands taller than the first.
-    #[test]
-    fn a_sentence_keeps_its_reading_order() {
-        let mut blocks = vec![block("Then the next line.", 72.0, 684.0, 200.0, 696.0)];
-        blocks.extend(italic_sentence().into_iter().rev());
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let xml = part(&docx(std::slice::from_ref(&p), "Opinion"), "word/document.xml");
-        assert_eq!(
-            word_paragraphs(&xml),
-            vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)]), runs(&[("Then the next line.", false)])],
-            "{xml}"
-        );
-    }
-
-    /// The text of a block leaves out the spaces at its ends, and the box of a run often takes in
-    /// its trailing space, so runs can touch. The source's own space still separates them; runs
-    /// that touch with no space between them (a superscript) stay joined.
-    #[test]
-    fn runs_keep_the_spaces_the_source_had_between_them() {
-        let blocks = vec![
-            Block { space_around: [false, true], ..block("Before", 72.0, 700.0, 113.0, 712.0) },
-            Block { italic: true, ..block("Chevron", 113.0, 700.0, 158.0, 712.0) },
-            Block { space_around: [true, false], ..block("after.", 158.0, 700.0, 190.0, 712.0) },
-            block("E = mc", 72.0, 660.0, 110.0, 672.0),
-            Block { size: 8.0, ..block("2", 110.0, 665.0, 115.0, 673.0) },
-        ];
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let xml = part(&docx(std::slice::from_ref(&p), "Spaces"), "word/document.xml");
-        assert_eq!(
-            word_paragraphs(&xml),
-            vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)]), runs(&[("E = mc", false), ("2", false)])],
-            "{xml}"
-        );
-    }
-    /// Text turned another way (a label up the margin) is not a run of the line it touches.
-    #[test]
-    fn turned_text_is_not_a_run_of_the_line_beside_it() {
-        let blocks = vec![block("Before", 72.0, 700.0, 110.0, 712.0), Block { rotation: 90.0, ..block("SIDE", 111.0, 690.0, 123.0, 720.0) }];
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let h = html(std::slice::from_ref(&p), "Turned");
-        assert!(h.contains("<p>Before</p>") && h.contains("<p>SIDE</p>"), "{h}");
-    }
-    /// A block that starts where the line above ends is the next line, not a run of it.
-    #[test]
-    fn a_block_on_the_next_line_starts_a_paragraph() {
-        let blocks = vec![
-            block("The first line ends here", 72.0, 700.0, 190.0, 712.0),
-            Block { italic: true, ..block("and the next starts there.", 190.5, 690.0, 320.0, 702.0) },
-        ];
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let xml = part(&docx(std::slice::from_ref(&p), "Lines"), "word/document.xml");
-        assert_eq!(word_paragraphs(&xml), vec![runs(&[("The first line ends here", false)]), runs(&[("and the next starts there.", true)])], "{xml}");
-    }
-
-    /// A superscript beside a table cell stays in the table: table detection consumes it before
-    /// paragraphs are formed, and a sentence after the table still keeps its italic run.
-    #[test]
-    fn table_cells_are_not_runs_of_a_paragraph() {
-        let mut blocks = vec![block("PLACE", 100.0, 700.0, 140.0, 712.0), block("PRIZE (euros)", 300.0, 700.0, 380.0, 712.0)];
-        for (n, (row, sup)) in [("1", "st"), ("2", "nd"), ("3", "rd")].iter().enumerate() {
-            let y = 680.0 - 20.0 * n as f64;
-            blocks.push(block(row, 100.0, y, 106.0, y + 12.0));
-            blocks.push(Block { size: 8.0, ..block(sup, 106.0, y + 5.0, 113.0, y + 13.0) });
-            blocks.push(block(&format!("{},000", 30 - 5 * n), 300.0, y, 340.0, y + 12.0));
-        }
-        blocks.extend(italic_sentence().into_iter().map(|b| Block { rect: [b.rect[0], b.rect[1] - 200.0, b.rect[2], b.rect[3] - 200.0], ..b }));
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let xml = part(&docx(std::slice::from_ref(&p), "Prizes"), "word/document.xml");
-        assert_eq!(xml.matches("<w:tbl>").count(), 1, "{xml}");
-        for cell in ["st", "nd", "rd", "30,000"] {
-            assert_eq!(xml.matches(&format!("preserve\">{cell}</w:t>")).count(), 1, "{cell}: {xml}");
-        }
-        // The cells are all in the table: the only flowing paragraph is the sentence.
-        assert_eq!(word_paragraphs(&xml), vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)])], "{xml}");
-    }
-
-    /// A bold lead-in followed by body text on its line is body text, not a heading; a heading
-    /// with a smaller footnote marker after it stays a heading.
-    #[test]
-    fn a_paragraph_is_a_heading_only_when_its_text_is() {
-        let blocks = vec![
-            Block { size: 24.0, ..block("Annual Report", 72.0, 740.0, 250.0, 764.0) },
-            Block { size: 14.0, ..block("1", 251.0, 752.0, 258.0, 766.0) },
-            Block { bold: true, ..block("Summary", 72.0, 700.0, 125.0, 712.0) },
-            block("the year closed with more members than it opened with, and fewer debts.", 128.0, 700.0, 540.0, 712.0),
-        ];
-        let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
-        let xml = part(&docx(std::slice::from_ref(&p), "Report"), "word/document.xml");
-        assert_eq!(xml.matches("<w:pStyle w:val=\"Heading1\"/>").count(), 1, "{xml}");
-        assert!(!xml.contains("Heading2"), "the lead-in made its paragraph a heading: {xml}");
-        assert_eq!(word_paragraphs(&xml).len(), 2, "{xml}");
-    }
-}
+mod tests;
diff --git a/crates/export/src/tests.rs b/crates/export/src/tests.rs
new file mode 100644
index 000000000..044ed236d
--- /dev/null
+++ b/crates/export/src/tests.rs
@@ -0,0 +1,780 @@
+use super::*;
+
+/// A page of `n` one-word blocks, each in its own size and colour.
+fn varied_page(n: usize) -> Page {
+    let blocks = (0..n)
+        .map(|i| Block {
+            text: "word".into(),
+            rect: [72.0, i as f64, 100.0, i as f64 + 1.0],
+            size: 4.0 + i as f64 * 0.5,
+            bold: false,
+            italic: false,
+            color: [(i % 256) as f64 / 255.0, (i / 256 % 256) as f64 / 255.0, 0.5],
+            rotation: 0.0,
+            space_around: [false; 2],
+        })
+        .collect();
+    Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None }
+}
+
+fn lookup_steps(f: impl FnOnce()) -> usize {
+    LOOKUP_STEPS.with(|c| c.set(0));
+    f();
+    LOOKUP_STEPS.with(|c| c.get())
+}
+
+#[test]
+fn many_distinct_sizes_are_counted_in_constant_steps_each() {
+    let pages = [varied_page(3000)];
+    let steps = lookup_steps(|| {
+        body_size(&pages);
+    });
+    assert!(steps <= 2 * 3000, "{steps} steps");
+}
+
+#[test]
+fn many_distinct_colours_take_constant_steps_each() {
+    let pages = [varied_page(3000)];
+    let mut out = String::new();
+    let steps = lookup_steps(|| out = rtf(&pages));
+    assert!(steps <= 4 * 3000, "{steps} steps");
+    assert!(out.contains("\\cf3000 ") || out.contains("\\cf3000\\"), "the last colour has the last slot");
+}
+
+fn page() -> Page {
+    let b = |t: &str, y: f64, size: f64, bold: bool| Block {
+        text: t.into(),
+        rect: [72.0, y, 500.0, y + size],
+        size,
+        bold,
+        italic: false,
+        color: [0.0; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    };
+    Page {
+        width: 612.0,
+        height: 792.0,
+        blocks: vec![
+            b("Body text after the picture, which is long enough to be the main text size of the page.", 400.0, 11.0, false),
+            b("Annual Report", 700.0, 24.0, true),
+            b("Overview", 650.0, 14.0, true),
+            b("Some <body> text & more of it so that eleven points is the body size here.", 620.0, 11.0, false),
+        ],
+        images: vec![Image {
+            ext: "png",
+            bytes: b"\x89PNG\r\n\x1a\n\0\0\0\rIHDR\0\0\0\x02\0\0\0\x03".as_slice().into(),
+            rect: [72.0, 450.0, 272.0, 600.0],
+            size: [200.0, 150.0],
+            rotation: 0.0,
+        }],
+        background: None,
+    }
+}
+
+#[test]
+fn html_has_headings_paragraphs_and_images_in_order() {
+    let h = html(&[page(), page()], "Report");
+    let order: Vec<usize> = ["<h1>Annual Report</h1>", "<h2>Overview</h2>", "<p>Some &lt;body&gt; text &amp;", "<img", "<p>Body text after"]
+        .iter()
+        .map(|x| h.find(x).unwrap_or_else(|| panic!("{x} missing in {h}")))
+        .collect();
+    assert!(order.windows(2).all(|w| w[0] < w[1]), "{order:?}");
+    assert_eq!(h.matches("<hr>").count(), 1);
+    assert_eq!(base64(b"Man"), "TWFu");
+    assert_eq!(base64(b"Ma"), "TWE=");
+}
+
+#[test]
+fn docx_is_a_word_package() {
+    let d = docx(&[page()], "Report");
+    assert!(d.starts_with(b"PK"));
+    let names: Vec<&str> =
+        ["[Content_Types].xml", "word/document.xml", "word/styles.xml", "word/_rels/document.xml.rels", "word/media/image1.png", "_rels/.rels"]
+            .to_vec();
+    for n in names {
+        assert!(d.windows(n.len()).any(|w| w == n.as_bytes()), "{n}");
+    }
+}
+
+#[test]
+fn word_does_not_invent_borders_for_aligned_invoice_fields() {
+    let xml = part(&docx(&[table_page()], "Invoice"), "word/document.xml");
+    assert!(xml.contains("<w:tbl>"));
+    assert!(!xml.contains("w:val=\"single\""), "text alignment is not evidence of a border: {xml}");
+    assert!(xml.contains("<w:insideH w:val=\"nil\"/>"));
+}
+
+#[test]
+fn word_table_cell_widths_follow_the_columns_they_span() {
+    let cell = |text: &str, span| Cell { text: text.into(), size: 11.0, bold: false, italic: false, color: [0.0; 3], span };
+    let table = Table {
+        rect: [0.0, 0.0, 300.0, 100.0],
+        cols: vec![0.0, 50.0, 150.0],
+        rows: vec![
+            vec![cell("First", 1), cell("Second", 1), cell("Third", 1)],
+            vec![cell("First", 1), cell("Last two", 2)],
+            vec![cell("First two", 2), cell("Third", 1)],
+            vec![cell("All", 3)],
+            vec![cell("First", 1)],
+        ],
+    };
+    let xml = docx_table(&table);
+    assert!(xml.contains("<w:gridCol w:w=\"1000\"/><w:gridCol w:w=\"2000\"/><w:gridCol w:w=\"3000\"/>"), "{xml}");
+    let widths: Vec<Vec<&str>> =
+        xml.split("<w:tr>").skip(1).map(|row| row.split("<w:tcW w:w=\"").skip(1).map(|cell| cell.split('"').next().unwrap()).collect()).collect();
+    assert_eq!(widths, vec![vec!["1000", "2000", "3000"], vec!["1000", "5000"], vec!["3000", "3000"], vec!["6000"], vec!["1000", "0", "0"]]);
+}
+
+#[test]
+fn word_keeps_a_page_with_a_clear_image_and_big_title_in_flow() {
+    // page() has a picture between paragraphs and a 24 pt title over 11 pt body text, but
+    // nothing overlaps: it must stay flowing paragraphs with the image inline.
+    let xml = part(&docx(&[page()], "Report"), "word/document.xml");
+    assert!(!xml.contains("position:absolute"), "nothing overlaps, so nothing floats: {xml}");
+    assert!(xml.contains("<wp:inline>"), "the picture stays inline: {xml}");
+    assert!(xml.contains("<w:pStyle w:val=\"Heading1\"/>"), "the title stays a heading: {xml}");
+    let (title, body) = (xml.find(">Annual Report</w:t>"), xml.find(">Body text after the picture"));
+    assert!(title.is_some() && body.is_some() && title < body, "reading order kept: {xml}");
+    // The same page with the picture moved over the body text floats.
+    let mut over = page();
+    over.images[0].rect = [72.0, 380.0, 272.0, 530.0];
+    let xml = part(&docx(&[over], "Report"), "word/document.xml");
+    assert!(xml.contains("position:absolute"), "an image over text floats: {xml}");
+}
+
+#[test]
+fn word_overlap_does_not_consume_invoice_body_space() {
+    let mut p = table_page();
+    p.blocks.push(Block {
+        text: "DRAFT".into(),
+        rect: [100.0, 200.0, 500.0, 700.0],
+        size: 100.0,
+        bold: false,
+        italic: false,
+        color: [0.8; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    });
+    p.images = page().images;
+    let xml = part(&docx(&[p], "Invoice"), "word/document.xml");
+    assert!(xml.contains("position:absolute"), "overlapping text must float: {xml}");
+    assert!(!xml.contains("<wp:inline>"), "images must not displace invoice text");
+    assert!(!xml.contains("<w:tbl>"), "the source text boxes must keep their positions");
+    assert_eq!(xml.matches(">DRAFT</w:t>").count(), 1);
+    assert_eq!(xml.matches("w:type=\"page\"").count(), 0);
+    assert!(xml.contains("margin-left:72.000pt;margin-top:160.000pt"), "Meter field keeps its source position: {xml}");
+    let watermark = xml.split(">DRAFT</w:t>").next().unwrap().rsplit("<v:rect ").next().unwrap();
+    assert!(watermark.contains("z-index:-2"), "watermark is behind foreground graphics");
+    // The picture is a DrawingML anchor behind the text (a VML rectangle shows no picture in Word).
+    assert!(!xml.contains("<v:imagedata"), "{xml}");
+    assert!(xml.contains("<wp:anchor ") && xml.contains("behindDoc=\"1\"") && xml.contains("<a:blip r:embed=\"rIdImg1\"/>"), "{xml}");
+}
+
+#[test]
+fn word_rotated_pages_keep_separate_page_sizes_and_unique_shapes() {
+    let mut p = table_page();
+    p.blocks[0].rotation = 45.0;
+    let mut second = p.clone();
+    second.width = 400.0;
+    second.height = 500.0;
+    let xml = part(&docx(&[p, second], "Two invoices"), "word/document.xml");
+    assert!(xml.contains("rotation:315.000"), "PDF y-up becomes Word y-down");
+    assert_eq!(xml.matches("<w:sectPr>").count(), 2);
+    assert!(xml.contains("<w:pgSz w:w=\"8000\" w:h=\"10000\"/>"));
+    assert_eq!(xml.matches("id=\"Text1\"").count(), 1);
+    assert_eq!(xml.matches(">Meter</w:t>").count(), 2);
+}
+
+/// #2992: pages that share a background colour get it as the Word document's page colour
+/// (with the setting that makes Word show it); differing or white backgrounds don't.
+#[test]
+fn docx_keeps_a_shared_page_background() {
+    let teal = Page { background: Some([0.0, 0.5, 0.5]), ..page() };
+    let zip = docx(&[teal.clone(), teal.clone()], "Teal");
+    let xml = part(&zip, "word/document.xml");
+    assert!(xml.contains("<w:background w:color=\"008080\"/><w:body>"), "{xml}");
+    assert!(part(&zip, "word/settings.xml").contains("<w:displayBackgroundShape/>"));
+    assert!(part(&zip, "[Content_Types].xml").contains("/word/settings.xml"));
+    assert!(part(&zip, "word/_rels/document.xml.rels").contains("Target=\"settings.xml\""));
+    let other = Page { background: Some([1.0, 0.0, 0.0]), ..page() };
+    for (pages, why) in [
+        (vec![teal.clone(), other], "different colours"),
+        (vec![teal.clone(), page()], "a page without one"),
+        (vec![Page { background: Some([1.0; 3]), ..page() }], "white"),
+        (vec![page()], "none"),
+    ] {
+        let zip = docx(&pages, "Plain");
+        assert!(!part(&zip, "word/document.xml").contains("<w:background"), "{why}");
+        assert!(!zip.windows(b"word/settings.xml".len()).any(|w| w == b"word/settings.xml"), "{why}");
+    }
+}
+
+/// One part of a package written by [`Zip`], inflated.
+pub(crate) fn part(zip: &[u8], name: &str) -> String {
+    let at = |i: usize, n: usize| zip[i..i + n].iter().rev().fold(0usize, |v, b| v << 8 | *b as usize);
+    let mut i = 0;
+    while zip[i..].starts_with(b"PK\x03\x04") {
+        let (size, name_len) = (at(i + 18, 4), at(i + 26, 2));
+        let data = i + 30 + name_len;
+        if &zip[i + 30..data] == name.as_bytes() {
+            let mut s = String::new();
+            std::io::Read::read_to_string(&mut flate2::read::DeflateDecoder::new(&zip[data..data + size]), &mut s).unwrap();
+            return s;
+        }
+        i = data + size;
+    }
+    panic!("{name} missing")
+}
+
+#[test]
+fn word_opens_text_with_control_characters_and_long_pages() {
+    // #72: text extracted without a usable /ToUnicode holds C0 controls, which XML forbids;
+    // Word then refused the whole file. A till receipt is also taller than Word's 22 in.
+    let mut p = page();
+    p.height = 2400.0;
+    p.blocks.push(Block {
+        text: "Total\u{0}\u{3}\u{c} 4.50\u{FFFF}\tGBP".into(),
+        rect: [72.0, 100.0, 300.0, 110.0],
+        size: f64::NAN,
+        bold: false,
+        italic: false,
+        color: [0.0; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    });
+    let xml = part(&docx(&[p.clone()], "Receipt\u{1}"), "word/document.xml");
+    assert!(xml.contains(">Total 4.50\tGBP</w:t>"), "{xml}");
+    assert!(!xml.chars().any(|c| !allowed(c)));
+    assert!(xml.contains("<w:pgSz w:w=\"12240\" w:h=\"31680\"/>"), "clamped to 22 in: {xml}");
+    assert!(xml.contains("<w:sz w:val=\"24\"/>"), "a non-finite size falls back to 12 pt");
+    assert!(rtf(&[p]).contains("Total 4.50\tGBP"));
+    // A narrow page keeps room for text: margins shrink.
+    let narrow = Page { width: 100.0, height: 200.0, ..page() };
+    let xml = part(&docx(&[narrow], "Narrow"), "word/document.xml");
+    assert!(xml.contains("<w:pgMar w:top=\"500\" w:right=\"250\" w:bottom=\"500\" w:left=\"250\""), "{xml}");
+}
+
+#[test]
+fn text_colour_survives_every_format() {
+    // #526: a dark green heading (0.05 0.23 0.18 rg) came out black in Word.
+    let mut p = page();
+    p.blocks[1].color = [0.05, 0.23, 0.18];
+    p.blocks[3].color = [f64::NAN, 2.0, -1.0];
+    let xml = part(&docx(&[p.clone()], "Colour"), "word/document.xml");
+    assert!(xml.contains("<w:color w:val=\"0D3B2E\"/>"), "{xml}");
+    assert!(xml.contains("<w:color w:val=\"00FF00\"/>"), "out-of-range values clamp: {xml}");
+    // Black text keeps Word's default colour.
+    assert_eq!(xml.matches("<w:color ").count(), 2, "{xml}");
+    let h = html(&[p.clone()], "Colour");
+    assert!(h.contains("<h1 style=\"color:#0D3B2E\">Annual Report</h1>"), "{h}");
+    assert!(h.contains("<p style=\"color:#00FF00\">"), "{h}");
+    let r = rtf(&[p.clone()]);
+    assert!(r.contains("{\\colortbl;\\red13\\green59\\blue46;\\red0\\green255\\blue0;}"), "{r}");
+    assert!(r.contains("\\cf1 Annual Report"), "{r}");
+    let ppt = pptx(&[p], "Colour");
+    let pxml = part(&ppt, "ppt/slides/slide1.xml");
+    assert!(pxml.contains("<a:srgbClr val=\"0D3B2E\"/>"), "{pxml}");
+    assert!(pxml.contains("<a:srgbClr val=\"00FF00\"/>"), "out-of-range values clamp: {pxml}");
+    // A table cell keeps its colour too.
+    let mut t = table_page();
+    t.blocks[0].color = [1.0, 0.0, 0.0];
+    let xml = part(&docx(&[t.clone()], "Grid"), "word/document.xml");
+    assert!(xml.contains("<w:color w:val=\"FF0000\"/>"), "{xml}");
+    assert!(html(&[t], "Grid").contains("style=\"color:#FF0000\""));
+}
+
+#[test]
+fn rtf_escapes_and_sizes() {
+    let mut p = page();
+    p.blocks.push(Block {
+        text: "Café {x}".into(),
+        rect: [72.0, 100.0, 200.0, 110.0],
+        size: 10.0,
+        bold: false,
+        italic: true,
+        color: [0.0; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    });
+    let r = rtf(&[p]);
+    assert!(r.starts_with("{\\rtf1") && r.ends_with('}'));
+    assert!(r.contains("\\fs48\\b Annual Report"));
+    assert!(r.contains("\\fs20\\i Caf\\u233? \\{x\\}"), "{r}");
+}
+
+/// A 3-column table with a spanning header row and a hole in the last row.
+fn table_page() -> Page {
+    let cell = |t: &str, x: f64, y: f64, w: f64| Block {
+        text: t.into(),
+        rect: [x, y, x + w, y + 12.0],
+        size: 11.0,
+        bold: false,
+        italic: false,
+        color: [0.0; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    };
+    Page {
+        width: 612.0,
+        height: 792.0,
+        blocks: vec![
+            cell("Meter", 72.0, 620.0, 120.0),
+            cell("Unit", 232.0, 620.0, 80.0),
+            cell("Reading", 392.0, 620.0, 100.0),
+            cell("A1", 72.0, 590.0, 120.0),
+            cell("kWh", 232.0, 590.0, 80.0),
+            cell("37414.00", 392.0, 590.0, 100.0),
+            cell("A2", 72.0, 560.0, 120.0),
+            cell("kW", 232.0, 560.0, 80.0),
+            // A2's row is missing its third cell (an empty cell in the grid).
+            cell("Totals", 72.0, 530.0, 240.0),
+            Block {
+                text: "Notes follow the table and are long enough to be the body text size of the page here.".into(),
+                rect: [72.0, 460.0, 500.0, 471.0],
+                size: 11.0,
+                bold: false,
+                italic: false,
+                color: [0.0; 3],
+                rotation: 0.0,
+                space_around: [false; 2],
+            },
+        ],
+        images: Vec::new(),
+        background: None,
+    }
+}
+
+#[test]
+fn grid_text_becomes_a_real_table_in_every_format() {
+    let p = table_page();
+    let h = html(std::slice::from_ref(&p), "Bill");
+    assert!(h.contains("<table>"), "{h}");
+    assert!(h.contains("<td colspan=\"2\">Totals</td>"), "spanning cell: {h}");
+    assert_eq!(h.matches("<tr>").count(), 4, "{h}");
+    assert!(h.contains("<td></td>"), "the hole is an empty cell: {h}");
+    assert!(h.contains("<p>Notes follow"), "the paragraph after the table stays: {h}");
+
+    let d = docx(std::slice::from_ref(&p), "Bill");
+    assert!(d.starts_with(b"PK"));
+    assert!(d.windows(b"word/document.xml".len()).any(|w| w == b"word/document.xml"));
+    let (tables, _) = tables(&p.blocks);
+    assert_eq!(tables.len(), 1);
+    let table_xml = docx_table(&tables[0]);
+    assert!(table_xml.contains("<w:tblGrid>"));
+    assert!(table_xml.contains("<w:gridSpan w:val=\"2\"/>"), "{table_xml}");
+    assert_eq!(table_xml.matches("<w:tr>").count(), 4);
+
+    let r = rtf(std::slice::from_ref(&p));
+    assert!(r.contains("\\trowd"), "{r}");
+    assert_eq!(r.matches("\\row").count(), 4);
+    // Boundaries precede the cells; "Totals" spans two columns, so it ends at the third edge.
+    assert!(r.contains("\\trowd\\trgaph108\\cellx4640\\cellx7840\\cellx9920{"), "{r}");
+    assert!(r.contains("\\trowd\\trgaph108\\cellx7840{\\intbl\\fs22 Totals}\\cell\\row"), "{r}");
+
+    let pt = pptx(std::slice::from_ref(&p), "Bill");
+    assert!(pt.starts_with(b"PK"));
+    assert!(pt.windows(b"ppt/slides/slide1.xml".len()).any(|w| w == b"ppt/slides/slide1.xml"));
+    let slide_xml = part(&pt, "ppt/slides/slide1.xml");
+    assert!(slide_xml.contains("<a:tbl>"));
+    assert!(slide_xml.contains("gridSpan=\"2\""));
+    assert_eq!(slide_xml.matches("<a:tr ").count(), 4);
+}
+
+#[test]
+fn a_staircase_of_blocks_is_not_a_huge_table() {
+    // Row k holds blocks in columns k and k + 1: every column has two members and every row
+    // two columns, so without a cap this would be one table of (n / 2)² cells.
+    let n = 4000;
+    let blocks: Vec<Block> = (0..n)
+        .map(|i| {
+            let (row, col) = (i / 2, i / 2 + i % 2);
+            let (x, y) = (10.0 + col as f64 * 20.0, 10_000.0 - row as f64 * 14.0);
+            Block {
+                text: "x".into(),
+                rect: [x, y, x + 8.0, y + 12.0],
+                size: 11.0,
+                bold: false,
+                italic: false,
+                color: [0.0; 3],
+                rotation: 0.0,
+                space_around: [false; 2],
+            }
+        })
+        .collect();
+    let started = std::time::Instant::now();
+    let (tables, _) = tables(&blocks);
+    assert!(tables.iter().all(|t| t.cols.len() <= MAX_COLS), "{} columns", tables.iter().map(|t| t.cols.len()).max().unwrap_or(0));
+    assert!(started.elapsed() < std::time::Duration::from_secs(5), "took {:?}", started.elapsed());
+}
+
+#[test]
+fn word_opens_tables_up_to_its_column_limit() {
+    // Rows of short numbers on a regular grid, n columns wide.
+    let grid = |n: usize| Page {
+        width: 1500.0,
+        height: 792.0,
+        blocks: (0..3)
+            .flat_map(|row| {
+                (0..n).map(move |col| {
+                    let (x, y) = (20.0 + col as f64 * 22.0, 700.0 - row as f64 * 14.0);
+                    Block {
+                        text: (col + 1).to_string(),
+                        rect: [x, y, x + 8.0, y + 8.0],
+                        size: 8.0,
+                        bold: false,
+                        italic: false,
+                        color: [0.0; 3],
+                        rotation: 0.0,
+                        space_around: [false; 2],
+                    }
+                })
+            })
+            .collect(),
+        images: Vec::new(),
+        background: None,
+    };
+    let grid_cols = |p: &Page| part(&docx(std::slice::from_ref(p), "Grid"), "word/document.xml").matches("<w:gridCol ").count();
+    assert_eq!(grid_cols(&grid(63)), 63, "63 columns is still a table");
+    // Word refuses to open a document with a 64-column table, so that grid stays text.
+    assert_eq!(grid_cols(&grid(64)), 0);
+}
+
+fn block(t: &str, x0: f64, y0: f64, x1: f64, y1: f64) -> Block {
+    Block {
+        text: t.into(),
+        rect: [x0, y0, x1, y1],
+        size: 12.0,
+        bold: false,
+        italic: false,
+        color: [0.0; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    }
+}
+
+/// #2806: a sentence whose link is set in another colour or font runs on as separate blocks
+/// on one line. They are not table columns, even when several such lines share left edges.
+#[test]
+fn a_link_inside_a_sentence_is_not_a_table_column() {
+    let blue = |t: &str, x0: f64, y0: f64, x1: f64, y1: f64| Block { color: [0.02, 0.388, 0.757], ..block(t, x0, y0, x1, y1) };
+    let p = Page {
+        width: 612.0,
+        height: 792.0,
+        blocks: vec![
+            block("6.3. 2. All content shown at", 121.7, 710.3, 272.0, 724.9),
+            blue("http", 273.5, 710.3, 294.1, 724.9),
+            blue("s", 294.1, 709.8, 298.8, 725.8),
+            blue("://women", 298.8, 710.3, 348.0, 724.9),
+            blue("g", 348.1, 709.8, 353.7, 725.8),
+            blue("randprix.fide.com", 353.7, 710.3, 443.2, 724.9),
+            block("shall be reviewed and approved by the Press Officer.", 164.3, 622.5, 533.1, 724.9),
+            block("6.3. 3. The Organiser shall warrant that", 121.7, 601.8, 345.1, 616.5),
+            blue("https://womengrandprix.fide.com", 350.2, 601.3, 519.9, 617.4),
+            block("is managed in a professional way and furthermore that it is capable of", 164.3, 557.9, 533.0, 616.5),
+            block("6. 3. 4. The Press Officer shall report to the FIDE Head of PR.", 121.7, 516.6, 530.3, 551.9),
+            block("conducted during a WGP tournament.", 164.3, 502.0, 352.5, 516.6),
+        ],
+        images: Vec::new(),
+        background: None,
+    };
+    let h = html(std::slice::from_ref(&p), "Regulations");
+    assert!(!h.contains("<table>"), "running text became a table: {h}");
+    // The link is a run of its sentence, in its own colour (#4158).
+    assert!(h.contains("<p>6.3. 2. All content shown at <span style=\"color:#0563C1\">http</span>"), "{h}");
+    for b in &p.blocks {
+        assert!(h.contains(&b.text), "{} was lost: {h}", b.text);
+    }
+}
+
+/// #2806: lines that each run on into a link starting at the same place are sentences, not a
+/// two-column table, even three in a row.
+#[test]
+fn sentences_that_run_on_into_links_are_not_a_table() {
+    let blue = |t: &str, x0: f64, y0: f64, x1: f64, y1: f64| Block { color: [0.02, 0.388, 0.757], ..block(t, x0, y0, x1, y1) };
+    let mut blocks = Vec::new();
+    for (n, lead) in ["Rules are published at", "Pairings are posted at", "Results are listed at"].iter().enumerate() {
+        let y = 700.0 - 16.0 * n as f64;
+        blocks.push(block(lead, 72.0, y, 211.0, y + 12.0));
+        blocks.push(blue("https://example.org/event", 212.5, y, 360.0, y + 12.0));
+    }
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let h = html(std::slice::from_ref(&p), "Event");
+    assert!(!h.contains("<table>"), "sentences became a table: {h}");
+    assert_eq!(h.matches("https://example.org/event").count(), 3, "{h}");
+}
+
+/// A continuation can drift into a grid column covered by the preceding cell's span.
+/// It must remain available as paragraph text if that slot never becomes an output cell.
+#[test]
+fn table_spans_do_not_consume_text_they_do_not_emit() {
+    let mut blocks = vec![
+        Block { size: 12.0, ..block("ABCDEFGHIJK", 72.1, 697.0, 151.3, 710.8) },
+        Block { size: 12.0, color: [0.0, 0.0, 1.0], ..block("LOST", 150.4, 697.0, 179.2, 710.8) },
+        Block { size: 12.0, ..block("R0", 250.0, 697.0, 264.4, 710.8) },
+    ];
+    for row in 1..=4 {
+        let y = 697.0 - f64::from(row) * 50.0;
+        for (text, left, right) in [(format!("L{row}"), 72.1, 86.5), (format!("M{row}"), 146.4, 160.8), (format!("R{row}"), 250.0, 264.4)] {
+            blocks.push(Block { size: 12.0, ..block(&text, left, y, right, y + 13.8) });
+        }
+    }
+    let p = Page { width: 612.0, height: 792.0, blocks, ..Page::default() };
+    let (tables, consumed) = tables(&p.blocks);
+    assert_eq!(tables.len(), 1);
+    assert_eq!(tables[0].rows[0][0].span, 2);
+    assert!(!consumed[1], "a covered slot did not emit its text");
+    assert!(consumed.iter().enumerate().all(|(index, used)| index == 1 || *used));
+    let outputs = [
+        html(std::slice::from_ref(&p), "Continuations"),
+        part(&docx(std::slice::from_ref(&p), "Continuations"), "word/document.xml"),
+        rtf(std::slice::from_ref(&p)),
+        part(&pptx(std::slice::from_ref(&p), "Continuations"), "ppt/slides/slide1.xml"),
+    ];
+    for output in outputs {
+        for b in &p.blocks {
+            assert_eq!(output.matches(&b.text).count(), 1, "{} must survive exactly once", b.text);
+        }
+    }
+}
+
+/// #2806: a superscript right after a number ("1" "st") continues its cell; the prize table
+/// around it stays a table.
+#[test]
+fn a_superscript_beside_a_number_keeps_its_table() {
+    let mut blocks = vec![block("PLACE", 100.0, 700.0, 140.0, 712.0), block("PRIZE (euros)", 300.0, 700.0, 380.0, 712.0)];
+    for (n, (row, sup)) in [("1", "st"), ("2", "nd"), ("3", "rd"), ("4", "th")].iter().enumerate() {
+        let y = 680.0 - 20.0 * n as f64;
+        blocks.push(block(row, 100.0, y, 106.0, y + 12.0));
+        blocks.push(Block { size: 8.0, ..block(sup, 106.0, y + 5.0, 113.0, y + 13.0) });
+        blocks.push(block(&format!("{},000", 30 - 5 * n), 300.0, y, 340.0, y + 12.0));
+    }
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let h = html(std::slice::from_ref(&p), "Prizes");
+    assert!(h.contains("<table>"), "the prize table was lost: {h}");
+    assert!(h.contains("30,000") && h.contains("15,000"), "{h}");
+    let (tables, consumed) = tables(&p.blocks);
+    assert!(consumed.iter().all(|used| *used), "ordinary table continuations stay in their cells");
+    let cells: Vec<&str> = tables.iter().flat_map(|t| &t.rows).flatten().map(|c| c.text.as_str()).collect();
+    assert!(["st", "nd", "rd", "th"].iter().all(|suffix| cells.contains(suffix)));
+}
+
+#[test]
+fn two_column_body_text_is_not_mistaken_for_a_table() {
+    let para = |t: &str, x: f64, y: f64| Block {
+        text: t.into(),
+        rect: [x, y, x + 200.0, y + 90.0], // nine lines tall: body text, not a cell
+        size: 11.0,
+        bold: false,
+        italic: false,
+        color: [0.0; 3],
+        rotation: 0.0,
+        space_around: [false; 2],
+    };
+    let p = Page {
+        width: 612.0,
+        height: 792.0,
+        blocks: vec![
+            para("Left column text of the page, long enough to be a flowing paragraph.", 72.0, 500.0),
+            para("Right column text of the page, long enough to be a flowing paragraph.", 320.0, 500.0),
+            para("Second left block, still a tall flowing paragraph rather than a cell.", 72.0, 400.0),
+            para("Second right block, still a tall flowing paragraph rather than a cell.", 320.0, 400.0),
+        ],
+        images: Vec::new(),
+        background: None,
+    };
+    let h = html(&[p], "Paper");
+    assert!(!h.contains("<table>"), "tall two-column text must stay paragraphs: {h}");
+}
+
+/// #1936: every picture Word is told to draw (`r:embed`) names a relationship whose target is a
+/// file in the package, with a content type; JPEG pictures too, inline or placed.
+#[test]
+fn word_pictures_resolve_to_media_in_the_package() {
+    let jpeg = Image { ext: "jpg", bytes: [0xFF, 0xD8, 0xFF, 0xD9].as_slice().into(), ..page().images[0].clone() };
+    for placed in [false, true] {
+        let mut p = page();
+        p.images = vec![jpeg.clone()];
+        if placed {
+            p.images[0].rect = [72.0, 640.0, 272.0, 790.0];
+            p.blocks[0].rect = [72.0, 700.0, 300.0, 760.0];
+        }
+        let zip = docx(&[p], "T");
+        let xml = part(&zip, "word/document.xml");
+        assert_eq!(xml.contains("<wp:anchor "), placed, "{xml}");
+        let rels = part(&zip, "word/_rels/document.xml.rels");
+        let embed = xml.split("r:embed=\"").nth(1).and_then(|r| r.split('"').next()).unwrap();
+        let rel = rels.split(&format!("Id=\"{embed}\"")).nth(1).unwrap();
+        assert!(rel.contains("relationships/image\""), "{rels}");
+        let target = rel.split("Target=\"").nth(1).and_then(|t| t.split('"').next()).unwrap();
+        assert_eq!(target, "media/image1.jpg");
+        assert!(zip.windows(21).any(|w| w == b"word/media/image1.jpg"));
+        assert!(part(&zip, "[Content_Types].xml").contains("Extension=\"jpg\" ContentType=\"image/jpeg\""));
+        assert!(xml.matches("<wp:docPr ").count() == 1 && !xml.contains("<v:imagedata"));
+    }
+}
+
+#[test]
+fn word_export_bounds_the_number_of_pictures_and_skips_empty_ones() {
+    let mut p = page();
+    let one = p.images[0].clone();
+    p.images = vec![Image { bytes: [].as_slice().into(), ..one.clone() }];
+    p.images.extend(std::iter::repeat_n(one, MAX_MEDIA + 10));
+    let zip = docx(&[p], "T");
+    let rels = part(&zip, "word/_rels/document.xml.rels");
+    assert_eq!(rels.matches("relationships/image\"").count(), MAX_MEDIA);
+}
+
+/// The flowing paragraphs of a Word document (table cells left out), each as its runs' text
+/// and whether the run is italic.
+fn word_paragraphs(xml: &str) -> Vec<Vec<(String, bool)>> {
+    let body = xml.split("<w:tbl>").map(|s| s.split_once("</w:tbl>").map_or(s, |(_, after)| after)).collect::<String>();
+    body.split("<w:p>")
+        .skip(1)
+        .map(|p| {
+            let p = p.split_once("</w:p>").map_or(p, |(inside, _)| inside);
+            p.split("<w:r>")
+                .skip(1)
+                .filter_map(|r| {
+                    let text = r.split_once("<w:t xml:space=\"preserve\">")?.1.split_once("</w:t>")?.0;
+                    Some((text.to_string(), r.contains("<w:i/>")))
+                })
+                .collect::<Vec<_>>()
+        })
+        .filter(|runs| !runs.is_empty())
+        .collect()
+}
+
+fn runs(r: &[(&str, bool)]) -> Vec<(String, bool)> {
+    r.iter().map(|(t, i)| (t.to_string(), *i)).collect()
+}
+
+/// "Before *Chevron* after." on one line: the roman text, the italic case name and the roman
+/// text after it, the way reading blocks split a sentence at its style changes (#4158). The
+/// italic face stands a little taller than the roman one around it.
+fn italic_sentence() -> Vec<Block> {
+    vec![
+        block("Before", 72.0, 700.0, 110.0, 712.0),
+        Block { italic: true, ..block("Chevron", 113.0, 700.0, 158.0, 712.6) },
+        block("after.", 161.0, 700.0, 190.0, 712.0),
+    ]
+}
+
+/// #4158: a run in another style inside a sentence stays in that sentence's paragraph, as a
+/// run in its own style, in every Office format.
+#[test]
+fn an_italic_word_stays_in_its_sentence() {
+    let mut blocks = italic_sentence();
+    blocks.push(block("The next line is a paragraph of its own.", 72.0, 684.0, 300.0, 696.0));
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let xml = part(&docx(std::slice::from_ref(&p), "Opinion"), "word/document.xml");
+    assert_eq!(
+        word_paragraphs(&xml),
+        vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)]), runs(&[("The next line is a paragraph of its own.", false)])],
+        "{xml}"
+    );
+    let h = html(std::slice::from_ref(&p), "Opinion");
+    assert!(h.contains("<p>Before <em>Chevron </em>after.</p>"), "{h}");
+    let r = rtf(std::slice::from_ref(&p));
+    assert!(r.contains("{\\pard\\fs24 Before {\\fs24\\b0\\i\\cf0 Chevron }{\\fs24\\b0\\i0\\cf0 after.}\\par}"), "{r}");
+    // The longest line is the slide's title; the sentence is one paragraph of the body.
+    let pxml = part(&pptx(std::slice::from_ref(&p), "Opinion"), "ppt/slides/slide1.xml");
+    assert!(
+        pxml.contains("<a:p><a:r><a:rPr sz=\"1200\"></a:rPr><a:t>Before </a:t></a:r><a:r><a:rPr sz=\"1200\" i=\"1\"></a:rPr><a:t>Chevron </a:t></a:r><a:r><a:rPr sz=\"1200\"></a:rPr><a:t>after.</a:t></a:r></a:p>"),
+        "{pxml}"
+    );
+}
+
+/// #4158: the runs keep their order along the line whatever order the blocks come in, and the
+/// paragraph keeps its place on the page, though the italic run stands taller than the first.
+#[test]
+fn a_sentence_keeps_its_reading_order() {
+    let mut blocks = vec![block("Then the next line.", 72.0, 684.0, 200.0, 696.0)];
+    blocks.extend(italic_sentence().into_iter().rev());
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let xml = part(&docx(std::slice::from_ref(&p), "Opinion"), "word/document.xml");
+    assert_eq!(
+        word_paragraphs(&xml),
+        vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)]), runs(&[("Then the next line.", false)])],
+        "{xml}"
+    );
+}
+
+/// The text of a block leaves out the spaces at its ends, and the box of a run often takes in
+/// its trailing space, so runs can touch. The source's own space still separates them; runs
+/// that touch with no space between them (a superscript) stay joined.
+#[test]
+fn runs_keep_the_spaces_the_source_had_between_them() {
+    let blocks = vec![
+        Block { space_around: [false, true], ..block("Before", 72.0, 700.0, 113.0, 712.0) },
+        Block { italic: true, ..block("Chevron", 113.0, 700.0, 158.0, 712.0) },
+        Block { space_around: [true, false], ..block("after.", 158.0, 700.0, 190.0, 712.0) },
+        block("E = mc", 72.0, 660.0, 110.0, 672.0),
+        Block { size: 8.0, ..block("2", 110.0, 665.0, 115.0, 673.0) },
+    ];
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let xml = part(&docx(std::slice::from_ref(&p), "Spaces"), "word/document.xml");
+    assert_eq!(
+        word_paragraphs(&xml),
+        vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)]), runs(&[("E = mc", false), ("2", false)])],
+        "{xml}"
+    );
+}
+/// Text turned another way (a label up the margin) is not a run of the line it touches.
+#[test]
+fn turned_text_is_not_a_run_of_the_line_beside_it() {
+    let blocks = vec![block("Before", 72.0, 700.0, 110.0, 712.0), Block { rotation: 90.0, ..block("SIDE", 111.0, 690.0, 123.0, 720.0) }];
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let h = html(std::slice::from_ref(&p), "Turned");
+    assert!(h.contains("<p>Before</p>") && h.contains("<p>SIDE</p>"), "{h}");
+}
+/// A block that starts where the line above ends is the next line, not a run of it.
+#[test]
+fn a_block_on_the_next_line_starts_a_paragraph() {
+    let blocks = vec![
+        block("The first line ends here", 72.0, 700.0, 190.0, 712.0),
+        Block { italic: true, ..block("and the next starts there.", 190.5, 690.0, 320.0, 702.0) },
+    ];
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let xml = part(&docx(std::slice::from_ref(&p), "Lines"), "word/document.xml");
+    assert_eq!(word_paragraphs(&xml), vec![runs(&[("The first line ends here", false)]), runs(&[("and the next starts there.", true)])], "{xml}");
+}
+
+/// A superscript beside a table cell stays in the table: table detection consumes it before
+/// paragraphs are formed, and a sentence after the table still keeps its italic run.
+#[test]
+fn table_cells_are_not_runs_of_a_paragraph() {
+    let mut blocks = vec![block("PLACE", 100.0, 700.0, 140.0, 712.0), block("PRIZE (euros)", 300.0, 700.0, 380.0, 712.0)];
+    for (n, (row, sup)) in [("1", "st"), ("2", "nd"), ("3", "rd")].iter().enumerate() {
+        let y = 680.0 - 20.0 * n as f64;
+        blocks.push(block(row, 100.0, y, 106.0, y + 12.0));
+        blocks.push(Block { size: 8.0, ..block(sup, 106.0, y + 5.0, 113.0, y + 13.0) });
+        blocks.push(block(&format!("{},000", 30 - 5 * n), 300.0, y, 340.0, y + 12.0));
+    }
+    blocks.extend(italic_sentence().into_iter().map(|b| Block { rect: [b.rect[0], b.rect[1] - 200.0, b.rect[2], b.rect[3] - 200.0], ..b }));
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let xml = part(&docx(std::slice::from_ref(&p), "Prizes"), "word/document.xml");
+    assert_eq!(xml.matches("<w:tbl>").count(), 1, "{xml}");
+    for cell in ["st", "nd", "rd", "30,000"] {
+        assert_eq!(xml.matches(&format!("preserve\">{cell}</w:t>")).count(), 1, "{cell}: {xml}");
+    }
+    // The cells are all in the table: the only flowing paragraph is the sentence.
+    assert_eq!(word_paragraphs(&xml), vec![runs(&[("Before ", false), ("Chevron ", true), ("after.", false)])], "{xml}");
+}
+
+/// A bold lead-in followed by body text on its line is body text, not a heading; a heading
+/// with a smaller footnote marker after it stays a heading.
+#[test]
+fn a_paragraph_is_a_heading_only_when_its_text_is() {
+    let blocks = vec![
+        Block { size: 24.0, ..block("Annual Report", 72.0, 740.0, 250.0, 764.0) },
+        Block { size: 14.0, ..block("1", 251.0, 752.0, 258.0, 766.0) },
+        Block { bold: true, ..block("Summary", 72.0, 700.0, 125.0, 712.0) },
+        block("the year closed with more members than it opened with, and fewer debts.", 128.0, 700.0, 540.0, 712.0),
+    ];
+    let p = Page { width: 612.0, height: 792.0, blocks, images: Vec::new(), background: None };
+    let xml = part(&docx(std::slice::from_ref(&p), "Report"), "word/document.xml");
+    assert_eq!(xml.matches("<w:pStyle w:val=\"Heading1\"/>").count(), 1, "{xml}");
+    assert!(!xml.contains("Heading2"), "the lead-in made its paragraph a heading: {xml}");
+    assert_eq!(word_paragraphs(&xml).len(), 2, "{xml}");
+}