diff --git a/crates/tools/src/snap.rs b/crates/tools/src/snap.rs
index 974081dd5..e79051b11 100644
--- a/crates/tools/src/snap.rs
+++ b/crates/tools/src/snap.rs
@@ -1368,880 +1368,4 @@ fn push_alignment_guide(out: &mut Vec<Overlay>, cx: &ToolContext, spread: Spread
 }
 
 #[cfg(test)]
-mod tests {
-    use std::sync::Arc;
-
-    use designcraft_compose::Cache;
-    use designcraft_doc::build::NewDocument;
-    use designcraft_doc::{Document, Guide, Item, Margins, PageSide, Selection, Shape, Stroke};
-    use designcraft_geom::shapes;
-    use designcraft_geom::{Affine, Unit};
-
-    use crate::layout::CanvasLayout;
-
-    use super::*;
-
-    /// Snapping offers the parent page the canvas shows: a single-sided page uses a two-page parent's first page.
-    #[test]
-    fn shown_parent_page_matches_page_side() {
-        let two = Document::new(&NewDocument { facing_pages: true, ..Default::default() });
-        assert_eq!(two.parents[0].pages.len(), 2);
-        assert_eq!(two.parents[0].parent_page_for_side(PageSide::Single), Some(0));
-        assert_eq!(two.parents[0].parent_page_for_side(PageSide::Left), Some(0));
-        assert_eq!(two.parents[0].parent_page_for_side(PageSide::Right), Some(1));
-        let mut one = Document::new(&NewDocument { facing_pages: false, ..Default::default() });
-        assert_eq!(one.parents[0].pages.len(), 1);
-        assert_eq!(one.parents[0].parent_page_for_side(PageSide::Single), Some(0));
-        Arc::make_mut(&mut one.parents[0]).pages.clear();
-        assert_eq!(one.parents[0].parent_page_for_side(PageSide::Single), None);
-    }
-
-    // The factory flags are const. Pin them anyway.
-    #[test]
-    #[allow(clippy::assertions_on_constants)]
-    fn factory_zone_is_four_pixels() {
-        assert!(SnapView::FACTORY.snap_to_guides);
-        assert!(!SnapView::FACTORY.snap_to_document_grid);
-        assert!(SnapView::FACTORY.smart_guides);
-        assert_eq!(SnapView::FACTORY.zone_px, 4.0);
-        assert!(!SnapView::OFF.any());
-        assert!(SnapView::FACTORY.any());
-    }
-
-    fn doc_with_items(moving: Rect, other: Rect, guide_x: f64) -> (Document, ItemId, ItemId) {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let make = |doc: &mut Document, rect: Rect| {
-            let id = ItemId(doc.alloc());
-            let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(rect));
-            doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-            id
-        };
-        let moving_id = make(&mut doc, moving);
-        let other_id = make(&mut doc, other);
-        let page = &mut Arc::make_mut(&mut doc.spreads[0]).pages[0];
-        page.guides.push(Guide { orientation: Orientation::Vertical, position: guide_x, spread: false, locked: false, layer: None, liquid: false });
-        (doc, moving_id, other_id)
-    }
-
-    fn ctx_on<'a>(doc: &'a Document, sel: &'a Selection, cache: &'a Cache, layout: &'a CanvasLayout) -> ToolContext<'a> {
-        ToolContext {
-            doc,
-            selection: sel,
-            cache,
-            layout,
-            zoom: 1.0,
-            layer: doc.default_layer(),
-            snap: SnapView::FACTORY,
-            unit: Unit::Points,
-            stroke_in_front: false,
-        }
-    }
-
-    fn y_req(rect: Rect) -> SnapRequest<'static> {
-        SnapRequest {
-            spread: SpreadRef::Doc(0),
-            gesture: Gesture::Move,
-            rect,
-            x_edges: [false, false, false],
-            y_edges: [true, true, true],
-            exclude: &[],
-            exclude_guides: &[],
-            copying: false,
-            lengths: [None, None],
-            angle: None,
-            radius: 0.0,
-            pointer: Point::new(0.0, 0.0),
-        }
-    }
-
-    fn move_req<'a>(rect: Rect, exclude: &'a [ItemId]) -> SnapRequest<'a> {
-        SnapRequest {
-            spread: SpreadRef::Doc(0),
-            gesture: Gesture::Move,
-            rect,
-            x_edges: [true, true, true],
-            y_edges: [false, false, false],
-            exclude,
-            exclude_guides: &[],
-            copying: false,
-            lengths: [None, None],
-            angle: None,
-            radius: 0.0,
-            pointer: Point::new(0.0, 0.0),
-        }
-    }
-
-    /// The bleed guide attracts like a ruler guide: a top edge 2 pt below the top bleed line
-    /// snaps up to it; with no bleed there is nothing there to snap to.
-    #[test]
-    fn bleed_guide_is_a_snap_target() {
-        let far = Rect::new(300.0, 300.0, 320.0, 320.0);
-        for (bleed, expected) in [([9.0, 9.0, 9.0, 9.0], -2.0), ([0.0; 4], 0.0)] {
-            let (mut doc, moving, _other) = doc_with_items(Rect::new(80.0, 100.0, 100.0, 140.0), far, 500.0);
-            doc.settings.bleed = bleed;
-            let top = doc.spreads[0].bounds().y0 - 9.0;
-            let rect = Rect::new(80.0, top + 2.0, 100.0, top + 40.0);
-            let cache = Cache::new();
-            let layout = CanvasLayout::new(&doc, false);
-            let sel = Selection::default();
-            let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-            cx.snap.zone_px = 4.0;
-            let hit = snap(
-                &cx,
-                SnapRequest {
-                    spread: SpreadRef::Doc(0),
-                    gesture: Gesture::Move,
-                    rect,
-                    x_edges: [false, false, false],
-                    y_edges: [true, true, true],
-                    exclude: &[moving],
-                    exclude_guides: &[],
-                    copying: false,
-                    lengths: [None, None],
-                    angle: None,
-                    radius: 0.0,
-                    pointer: Point::new(0.0, 0.0),
-                },
-            );
-            assert!((hit.delta.y - expected).abs() < 1e-6, "bleed {bleed:?}: {:?}", hit.delta);
-        }
-    }
-
-    #[test]
-    fn guide_beats_a_closer_object_edge() {
-        // Right edge at 100.5. Object edge at 100 (0.5 away). Guide at 104 (3.5 away). Zone is 4.
-        let (doc, moving, _other) = doc_with_items(Rect::new(80.0, 100.0, 100.5, 140.0), Rect::new(90.0, 100.0, 100.0, 160.0), 104.0);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.zone_px = 4.0;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(80.0, 100.0, 100.5, 140.0),
-                x_edges: [true, true, true],
-                y_edges: [false, false, false],
-                exclude: &[moving],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x - 3.5).abs() < 1e-6);
-        assert!(hit.guides.is_empty());
-    }
-
-    /// A dragged guide is not its own target: excluded, the guide at 104 doesn't pull a line at 102.
-    /// Nor does the baseline grid pull it.
-    #[test]
-    fn excluded_guide_is_not_a_target() {
-        let far = Rect::new(400.0, 400.0, 420.0, 420.0);
-        let (doc, _, _) = doc_with_items(far, far, 104.0);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let cx = ctx_on(&doc, &sel, &cache, &layout);
-        let line = Rect::new(102.0, 100.0, 102.0, 300.0);
-        let dragged = [designcraft_doc::GuideSel { spread: SpreadRef::Doc(0), page: 0, index: 0 }];
-        let hit = snap(&cx, move_req(line, &[]));
-        assert!((hit.delta.x - 2.0).abs() < 1e-6, "{:?}", hit.delta);
-        let hit = snap(&cx, SnapRequest { exclude_guides: &dragged, ..move_req(line, &[]) });
-        assert_eq!(hit.delta.x, 0.0);
-        // A dragged guide passes the baseline grid's lines (36 + 12n), which a moved object meets.
-        let flat = Rect::new(100.0, 86.0, 300.0, 86.0);
-        assert!((snap(&cx, y_req(flat)).delta.y - -2.0).abs() < 1e-6);
-        assert_eq!(snap(&cx, SnapRequest { gesture: Gesture::Guide, ..y_req(flat) }).delta.y, 0.0);
-    }
-
-    #[test]
-    fn parent_centered_stroke_attracts_at_the_outer_edge() {
-        let mut doc = Document::new(&NewDocument::default());
-        let pid = doc.add_parent("A", "A-Parent", 1, 12.0, Margins::uniform(36.0));
-        doc.apply_parent(&[0], Some(pid)).unwrap();
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let (ppi, ppg) = doc.parent_page_for(0).unwrap();
-        let parent_x = doc.parents[ppi].pages[ppg].x;
-        let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(parent_x + 72.0, 140.0, parent_x + 252.0, 300.0)));
-        item.stroke = Stroke::default(); // 1 pt, center
-        doc.insert_item(SpreadRef::Parent(ppi), item, None).unwrap();
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        // Moving left edge at 253. Visible parent right edge is 252.5.
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(253.0, 140.0, 353.0, 240.0),
-                x_edges: [true, false, false],
-                y_edges: [false, false, false],
-                exclude: &[],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x - -0.5).abs() < 1e-6, "delta {}", hit.delta.x);
-    }
-
-    #[test]
-    fn object_edge_snaps_when_guide_snap_is_off() {
-        let (doc, moving, _other) = doc_with_items(Rect::new(80.0, 100.0, 100.5, 140.0), Rect::new(90.0, 100.0, 100.0, 160.0), 104.0);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(80.0, 100.0, 100.5, 140.0),
-                x_edges: [true, true, true],
-                y_edges: [false, false, false],
-                exclude: &[moving],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x - -0.5).abs() < 1e-6);
-        assert!(matches!(hit.guides.first(), Some(Overlay::Guide { .. })));
-    }
-
-    #[test]
-    fn hidden_layer_guide_is_not_a_target() {
-        let (mut doc, moving, _) = doc_with_items(Rect::new(80.0, 100.0, 102.0, 140.0), Rect::new(300.0, 100.0, 340.0, 140.0), 104.0);
-        let layer = doc.default_layer();
-        doc.layers.iter_mut().find(|l| l.id == layer).unwrap().visible = false;
-        Arc::make_mut(&mut doc.spreads[0]).pages[0].guides[0].layer = Some(layer);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let cx = ctx_on(&doc, &sel, &cache, &layout);
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(80.0, 100.0, 102.0, 140.0),
-                x_edges: [false, false, true],
-                y_edges: [false, false, false],
-                exclude: &[moving],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert_eq!(hit.delta.x, 0.0);
-    }
-
-    #[test]
-    fn alt_copy_snaps_to_the_original() {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(100.0, 40.0, 160.0, 80.0)));
-        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(162.0, 40.0, 222.0, 80.0),
-                x_edges: [true, false, false],
-                y_edges: [false, false, false],
-                exclude: &[id],
-                exclude_guides: &[],
-                copying: true,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x - -2.0).abs() < 1e-6);
-    }
-
-    #[test]
-    fn alt_copy_does_not_stick_to_the_preview() {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let make = |doc: &mut Document, rect: Rect| {
-            let id = ItemId(doc.alloc());
-            let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(rect));
-            doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-            id
-        };
-        let original = make(&mut doc, Rect::new(100.0, 40.0, 160.0, 80.0));
-        let ghost = make(&mut doc, Rect::new(161.0, 40.0, 221.0, 80.0));
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::items(vec![ghost]);
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(161.0, 40.0, 221.0, 80.0),
-                x_edges: [true, false, false],
-                y_edges: [false, false, false],
-                exclude: &[original],
-                exclude_guides: &[],
-                copying: true,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x - -1.0).abs() < 1e-6, "delta.x = {}", hit.delta.x);
-    }
-
-    #[test]
-    fn parent_page_guides_snap_on_the_document_page() {
-        // Facing document: page 1 is a right page at x = 0; its parent page is A's right page at
-        // x = 612 in the parent spread.
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(80.0, 100.0, 100.5, 140.0)));
-        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        Arc::make_mut(&mut doc.parents[0]).pages[1].guides.push(Guide {
-            orientation: Orientation::Vertical,
-            position: 612.0 + 104.0,
-            spread: false,
-            locked: false,
-            layer: None,
-            liquid: false,
-        });
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.zone_px = 4.0;
-        let hit = snap(&cx, move_req(Rect::new(80.0, 100.0, 100.5, 140.0), &[id]));
-        assert!((hit.delta.x - 3.5).abs() < 1e-6, "snaps to the parent guide at x = 104: {:?}", hit.delta);
-    }
-
-    #[test]
-    fn grid_beats_a_closer_guide() {
-        let mut doc = Document::new(&NewDocument::default());
-        doc.settings.grid.horizontal = 72.0;
-        doc.settings.grid.vertical = 72.0;
-        doc.settings.grid.subdivisions = 8; // 9 pt
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(10.0, 10.0, 40.0, 40.0)));
-        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        // Guide 1 pt away at x = 11. Subdivision line at 9 is 1 pt the other way. Grid must win.
-        Arc::make_mut(&mut doc.spreads[0]).pages[0].guides.push(Guide {
-            orientation: Orientation::Vertical,
-            position: 11.0,
-            spread: true,
-            locked: false,
-            layer: None,
-            liquid: false,
-        });
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_document_grid = true;
-        let hit = snap(&cx, move_req(Rect::new(10.0, 10.0, 40.0, 40.0), &[id]));
-        assert!((hit.delta.x - -1.0).abs() < 1e-6);
-        assert!(hit.guides.is_empty());
-    }
-
-    #[test]
-    fn hidden_baseline_still_snaps_and_zero_increment_does_not() {
-        let mut doc = Document::new(&NewDocument::default());
-        doc.settings.baseline_grid.start = 36.0;
-        doc.settings.baseline_grid.increment = 12.0;
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let cx = ctx_on(&doc, &sel, &cache, &layout);
-        // Top at 49 wants the line at 48 (start 36, increment 12). The margin at 36 is 13 pt away.
-        let hit = snap(&cx, y_req(Rect::new(100.0, 49.0, 140.0, 80.0)));
-        assert!((hit.delta.y - -1.0).abs() < 1e-6);
-        let mut dead = doc.clone();
-        dead.settings.baseline_grid.increment = 0.0;
-        let layout = CanvasLayout::new(&dead, false);
-        let cx = ctx_on(&dead, &sel, &cache, &layout);
-        let hit = snap(&cx, y_req(Rect::new(100.0, 49.0, 140.0, 80.0)));
-        assert_eq!(hit.delta.y, 0.0);
-    }
-
-    #[test]
-    fn baseline_relative_to_the_top_margin_snaps_from_the_margin() {
-        let mut doc = Document::new(&NewDocument::default());
-        std::sync::Arc::make_mut(&mut doc.spreads[0]).pages[0].margins.top = 37.0;
-        doc.settings.baseline_grid.start = 0.0;
-        doc.settings.baseline_grid.increment = 10.0;
-        doc.settings.baseline_grid.relative_to = designcraft_doc::GridRelative::TopMargin;
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let cx = ctx_on(&doc, &sel, &cache, &layout);
-        // Lines at 37 + 10n: a top at 58 goes up to 57, not down to the page-relative 60.
-        let hit = snap(&cx, y_req(Rect::new(100.0, 58.0, 140.0, 80.0)));
-        assert!((hit.delta.y - -1.0).abs() < 1e-6, "{}", hit.delta.y);
-    }
-
-    #[test]
-    fn nearer_of_margin_and_baseline_wins() {
-        // Bottom margin at 792 - 54 = 738, between baseline lines 732 and 744.
-        let doc = Document::new(&NewDocument {
-            margins: designcraft_doc::Margins { top: 54.0, bottom: 54.0, inside: 54.0, outside: 42.0 },
-            ..Default::default()
-        });
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        // At 50% the 4 px zone is 8 pt: both the margin and a baseline line are in reach.
-        let cx = ToolContext { zoom: 0.5, ..ctx_on(&doc, &sel, &cache, &layout) };
-        let bottom = |y1: f64| SnapRequest { y_edges: [false, false, true], gesture: Gesture::Resize, ..y_req(Rect::new(100.0, 600.0, 140.0, y1)) };
-        assert!((snap(&cx, bottom(739.5)).delta.y - -1.5).abs() < 1e-6, "the margin is nearer");
-        assert!((snap(&cx, bottom(742.5)).delta.y - 1.5).abs() < 1e-6, "the baseline line is nearer");
-        assert!((snap(&cx, bottom(741.0)).delta.y - -3.0).abs() < 1e-6, "a tie goes to the margin");
-    }
-
-    #[test]
-    fn rotated_item_matches_its_own_side() {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 200.0, 40.0)));
-        item.xf = Affine::rotate((-30.0_f64).to_radians());
-        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        cx.snap.snap_to_document_grid = false;
-        // Width 193.2 is the axis-aligned box. 200 is the side. Zone 4 reaches 200 from 197, not from 193.
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Resize,
-                rect: Rect::new(80.0, 200.0, 277.0, 280.0),
-                x_edges: [false, false, true],
-                y_edges: [false, false, false],
-                exclude: &[],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [Some(197.0), None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(277.0, 240.0),
-            },
-        );
-        assert!((hit.delta.x - 3.0).abs() < 1e-6);
-        assert!(matches!(hit.guides.last(), Some(Overlay::Measure { text, .. }) if text.contains("200")));
-    }
-
-    #[test]
-    fn grouped_child_matches_spread_side() {
-        // Group scale 2 on X and 1 on Y. Child rotated -90 degrees (decompose reports +90).
-        // Spread-space sides are local width times 1 (100) and local height times 2 (80).
-        // 82 is 2 pt from 80 and far from 200, which is what per-node scales would offer.
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let child_id = ItemId(doc.alloc());
-        let mut child = Item::new(child_id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 100.0, 40.0)));
-        child.xf = Affine::rotate((-90.0_f64).to_radians());
-        let group_id = ItemId(doc.alloc());
-        let mut group = Item::new(group_id, layer, Shape::Group, designcraft_geom::PathData::default());
-        group.xf = Affine::scale_non_uniform(2.0, 1.0);
-        group.content = designcraft_doc::Content::Group { items: vec![std::sync::Arc::new(child)] };
-        doc.insert_item(SpreadRef::Doc(0), group, None).unwrap();
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        cx.snap.snap_to_document_grid = false;
-        cx.snap.align_edges = false;
-        cx.snap.align_centers = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Resize,
-                rect: Rect::new(200.0, 200.0, 282.0, 240.0),
-                x_edges: [false, false, true],
-                y_edges: [false, false, false],
-                exclude: &[],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [Some(82.0), None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(282.0, 220.0),
-            },
-        );
-        assert!((hit.delta.x - -2.0).abs() < 1e-6, "delta.x = {}, want -2 toward local height times 2", hit.delta.x);
-    }
-
-    #[test]
-    fn move_matches_a_stationary_gap() {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        // Stationary gap of 20 between [0,40] and [60,90]. Moving box at [112,150], 22 away from 90.
-        for r in [Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(60.0, 0.0, 90.0, 30.0), Rect::new(112.0, 0.0, 150.0, 30.0)] {
-            let id = ItemId(doc.alloc());
-            let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(r));
-            doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        }
-        let moving = doc.spreads[0].items[2].id;
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Move,
-                rect: Rect::new(112.0, 0.0, 150.0, 30.0),
-                x_edges: [true, true, true],
-                y_edges: [false, false, false],
-                exclude: &[moving],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x - -2.0).abs() < 1e-6);
-        assert!(hit.guides.iter().any(|g| matches!(g, Overlay::Gap { .. })));
-    }
-
-    fn doc_with_rects(rects: &[Rect]) -> Document {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        for &r in rects {
-            let id = ItemId(doc.alloc());
-            let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(r));
-            doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        }
-        doc
-    }
-
-    fn gap_overlays(guides: &[Overlay]) -> usize {
-        guides.iter().filter(|g| matches!(g, Overlay::Gap { .. })).count()
-    }
-
-    // #188: a box dragged between two others snaps to the middle and marks both gaps.
-    #[test]
-    fn move_centers_between_two_boxes_side_by_side() {
-        // Neighbours end at 40 and start at 160. The 30 wide mover at [83,113] is 2 left of centre.
-        let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(160.0, 0.0, 200.0, 30.0)]);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(&cx, move_req(Rect::new(83.0, 5.0, 113.0, 25.0), &[]));
-        assert!((hit.delta.x - 2.0).abs() < 1e-6, "{}", hit.delta.x);
-        assert_eq!(gap_overlays(&hit.guides), 2);
-    }
-
-    #[test]
-    fn move_centers_between_two_boxes_stacked() {
-        let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 30.0, 40.0), Rect::new(0.0, 160.0, 30.0, 200.0)]);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(&cx, y_req(Rect::new(5.0, 83.0, 25.0, 113.0)));
-        assert!((hit.delta.y - 2.0).abs() < 1e-6, "{}", hit.delta.y);
-        assert_eq!(gap_overlays(&hit.guides), 2);
-    }
-
-    fn with_baseline_grid(mut doc: Document) -> Document {
-        doc.settings.baseline_grid.start = 36.0;
-        doc.settings.baseline_grid.increment = 12.0;
-        doc
-    }
-
-    // #188: with Snap to Guides on, the hidden baseline grid took vertical moves first.
-    #[test]
-    fn vertical_centering_beats_a_closer_baseline() {
-        // Middle at 200. Mover centre 198 (+2). Its top and bottom are 3 from lines 180 and 216.
-        let doc = with_baseline_grid(doc_with_rects(&[Rect::new(100.0, 100.0, 130.0, 140.0), Rect::new(100.0, 260.0, 130.0, 300.0)]));
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let cx = ctx_on(&doc, &sel, &cache, &layout);
-        let hit = snap(&cx, y_req(Rect::new(105.0, 183.0, 125.0, 213.0)));
-        assert!((hit.delta.y - 2.0).abs() < 1e-6, "{}", hit.delta.y);
-        assert_eq!(gap_overlays(&hit.guides), 2);
-    }
-
-    #[test]
-    fn vertical_alignment_beats_a_closer_baseline() {
-        // Top 107 is 1 from the line at 108 and 2 from the other box's top at 105.
-        let doc = with_baseline_grid(doc_with_rects(&[Rect::new(300.0, 105.0, 340.0, 135.0)]));
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let cx = ctx_on(&doc, &sel, &cache, &layout);
-        let hit = snap(&cx, y_req(Rect::new(100.0, 107.0, 140.0, 137.0)));
-        assert!((hit.delta.y - -2.0).abs() < 1e-6, "{}", hit.delta.y);
-        assert!(hit.guides.iter().any(|g| matches!(g, Overlay::Guide { .. })));
-    }
-
-    #[test]
-    fn move_off_center_outside_the_zone_does_not_center() {
-        // 10 off centre, zone 4.
-        let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(160.0, 0.0, 200.0, 30.0)]);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(&cx, move_req(Rect::new(95.0, 5.0, 125.0, 25.0), &[]));
-        assert_eq!(hit.delta.x, 0.0);
-        assert_eq!(gap_overlays(&hit.guides), 0);
-    }
-
-    #[test]
-    fn centering_needs_smart_spacing() {
-        let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(160.0, 0.0, 200.0, 30.0)]);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        cx.snap.smart_spacing = false;
-        let hit = snap(&cx, move_req(Rect::new(83.0, 5.0, 113.0, 25.0), &[]));
-        assert_eq!(hit.delta.x, 0.0);
-    }
-
-    #[test]
-    fn create_does_not_match_spacing() {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        for r in [Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(60.0, 0.0, 90.0, 30.0)] {
-            let id = ItemId(doc.alloc());
-            let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(r));
-            doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        }
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        cx.snap.smart_dimensions = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Create,
-                rect: Rect::new(112.0, 0.0, 150.0, 30.0),
-                x_edges: [true, true, true],
-                y_edges: [false, false, false],
-                exclude: &[],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [Some(38.0), None],
-                angle: None,
-                radius: 0.0,
-                pointer: Point::new(0.0, 0.0),
-            },
-        );
-        assert!((hit.delta.x).abs() < 1e-6);
-    }
-
-    #[test]
-    fn rotation_matches_another_items_angle() {
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 80.0, 40.0)));
-        item.xf = Affine::rotate((-30.0_f64).to_radians());
-        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Rotate,
-                rect: Rect::new(100.0, 100.0, 160.0, 140.0),
-                x_edges: [false, false, false],
-                y_edges: [false, false, false],
-                exclude: &[],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: Some(28.0),
-                radius: 80.0,
-                pointer: Point::new(180.0, 120.0),
-            },
-        );
-        let angle = hit.angle.expect("rotation hit");
-        assert!((angle - 30.0).abs() < 1e-6);
-        assert!(matches!(hit.guides.first(), Some(Overlay::Measure { .. })));
-    }
-
-    #[test]
-    fn parent_item_angle_matches() {
-        // Document::new already has A-Parent. Apply a second parent and insert on the
-        // page parent_page_for shows, not Parent(0). A facing right page sits near x 612.
-        let mut doc = Document::new(&NewDocument::default());
-        let pid = doc.add_parent("B", "B-Parent", 1, 12.0, Margins::uniform(36.0));
-        doc.apply_parent(&[0], Some(pid)).unwrap();
-        std::sync::Arc::make_mut(&mut doc.spreads[0]).pages[0].show_parent_items = true;
-        let (ppi, ppg) = doc.parent_page_for(0).unwrap();
-        let parent_x = doc.parents[ppi].pages[ppg].x;
-        let rect = Rect::new(parent_x + 72.0, 140.0, parent_x + 152.0, 180.0);
-        let center = rect.center();
-        let layer = doc.default_layer();
-        let id = ItemId(doc.alloc());
-        let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(rect));
-        item.xf = Affine::translate((center.x, center.y)) * Affine::rotate((-30.0_f64).to_radians()) * Affine::translate((-center.x, -center.y));
-        doc.insert_item(SpreadRef::Parent(ppi), item, None).unwrap();
-        assert!(doc.spreads[0].items.iter().all(|it| (designcraft_geom::decompose::decompose(it.xf).rotation - 30.0).abs() > 1.0));
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let hit = snap(
-            &cx,
-            SnapRequest {
-                spread: SpreadRef::Doc(0),
-                gesture: Gesture::Rotate,
-                rect: Rect::new(100.0, 100.0, 160.0, 140.0),
-                x_edges: [false, false, false],
-                y_edges: [false, false, false],
-                exclude: &[],
-                exclude_guides: &[],
-                copying: false,
-                lengths: [None, None],
-                angle: Some(28.0),
-                radius: 80.0,
-                pointer: Point::new(180.0, 120.0),
-            },
-        );
-        let angle = hit.angle.expect("parent rotation hit");
-        assert!((angle - 30.0).abs() < 1e-6);
-    }
-
-    #[test]
-    fn rotated_group_uses_the_per_child_union() {
-        // Two children do not fill their local union. Rotating that union as one rectangle
-        // swings the empty corners out. The snap target is each child's visible box, transformed, then united.
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let mut child_a = Item::new(ItemId(doc.alloc()), layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 10.0, 10.0)));
-        child_a.stroke = Stroke { weight: 2.0, ..Stroke::default() };
-        let child_b = Item::new(ItemId(doc.alloc()), layer, Shape::Rectangle, shapes::rectangle(Rect::new(40.0, 30.0, 50.0, 40.0)));
-        let mut group = Item::new(ItemId(doc.alloc()), layer, Shape::Group, designcraft_geom::PathData::default());
-        let xf = Affine::translate((300.0, 400.0)) * Affine::rotate((-45.0_f64).to_radians());
-        group.xf = xf;
-        group.content = designcraft_doc::Content::Group { items: vec![Arc::new(child_a), Arc::new(child_b)] };
-        doc.insert_item(SpreadRef::Doc(0), group, None).unwrap();
-        let a_vis = Rect::new(-1.0, -1.0, 11.0, 11.0);
-        let b_vis = Rect::new(40.0, 30.0, 50.0, 40.0);
-        let per_child = xf.transform_rect_bbox(a_vis).union(xf.transform_rect_bbox(b_vis));
-        let rotated_union = xf.transform_rect_bbox(a_vis.union(b_vis));
-        // At 45 degrees the empty corners move y, not x. The two boxes share x0.
-        assert!((per_child.y0 - rotated_union.y0).abs() > 1.0, "fixture does not separate the two boxes");
-        let gap = 2.0;
-        // A short rect just above the per-child top. Its other edges stay outside the zone of the rotated union.
-        let moving = Rect::new(per_child.x0, per_child.y0 - gap - 4.0, per_child.x0 + 20.0, per_child.y0 - gap);
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        cx.snap.snap_to_document_grid = false;
-        let hit = snap(&cx, y_req(moving));
-        assert!((hit.delta.y - gap).abs() < 1e-4, "delta.y {}, want {gap} onto {}", hit.delta.y, per_child.y0);
-        let wrong = rotated_union.y0 - moving.y1;
-        assert!((hit.delta.y - wrong).abs() > 1.0, "delta matched the rotated local union");
-    }
-
-    #[test]
-    fn rotated_group_child_does_not_offer_local_zero() {
-        // The group is at 30 degrees. Its child stays at local 0, so the absolute angle is 30.
-        // 2 degrees is inside the zone of 0 and far from 30. Local 0 must not win.
-        let mut doc = Document::new(&NewDocument::default());
-        let layer = doc.default_layer();
-        let child = Item::new(ItemId(doc.alloc()), layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 40.0, 20.0)));
-        let mut group = Item::new(ItemId(doc.alloc()), layer, Shape::Group, designcraft_geom::PathData::default());
-        group.xf = Affine::rotate((-30.0_f64).to_radians());
-        group.content = designcraft_doc::Content::Group { items: vec![Arc::new(child)] };
-        doc.insert_item(SpreadRef::Doc(0), group, None).unwrap();
-        let cache = Cache::new();
-        let layout = CanvasLayout::new(&doc, false);
-        let sel = Selection::default();
-        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
-        cx.snap.snap_to_guides = false;
-        let ask = |angle: f64| {
-            snap(
-                &cx,
-                SnapRequest {
-                    spread: SpreadRef::Doc(0),
-                    gesture: Gesture::Rotate,
-                    rect: Rect::new(100.0, 100.0, 160.0, 140.0),
-                    x_edges: [false, false, false],
-                    y_edges: [false, false, false],
-                    exclude: &[],
-                    exclude_guides: &[],
-                    copying: false,
-                    lengths: [None, None],
-                    angle: Some(angle),
-                    radius: 80.0,
-                    pointer: Point::new(180.0, 120.0),
-                },
-            )
-        };
-        let near_zero = ask(2.0);
-        assert!(near_zero.angle.is_none(), "local 0 was a target: {:?}", near_zero.angle);
-        let near_group = ask(28.0);
-        let angle = near_group.angle.expect("absolute 30");
-        assert!((angle - 30.0).abs() < 1e-6, "angle {angle}");
-    }
-}
+mod tests;
diff --git a/crates/tools/src/snap/tests.rs b/crates/tools/src/snap/tests.rs
new file mode 100644
index 000000000..2dfccafae
--- /dev/null
+++ b/crates/tools/src/snap/tests.rs
@@ -0,0 +1,875 @@
+use std::sync::Arc;
+
+use designcraft_compose::Cache;
+use designcraft_doc::build::NewDocument;
+use designcraft_doc::{Document, Guide, Item, Margins, PageSide, Selection, Shape, Stroke};
+use designcraft_geom::shapes;
+use designcraft_geom::{Affine, Unit};
+
+use crate::layout::CanvasLayout;
+
+use super::*;
+
+/// Snapping offers the parent page the canvas shows: a single-sided page uses a two-page parent's first page.
+#[test]
+fn shown_parent_page_matches_page_side() {
+    let two = Document::new(&NewDocument { facing_pages: true, ..Default::default() });
+    assert_eq!(two.parents[0].pages.len(), 2);
+    assert_eq!(two.parents[0].parent_page_for_side(PageSide::Single), Some(0));
+    assert_eq!(two.parents[0].parent_page_for_side(PageSide::Left), Some(0));
+    assert_eq!(two.parents[0].parent_page_for_side(PageSide::Right), Some(1));
+    let mut one = Document::new(&NewDocument { facing_pages: false, ..Default::default() });
+    assert_eq!(one.parents[0].pages.len(), 1);
+    assert_eq!(one.parents[0].parent_page_for_side(PageSide::Single), Some(0));
+    Arc::make_mut(&mut one.parents[0]).pages.clear();
+    assert_eq!(one.parents[0].parent_page_for_side(PageSide::Single), None);
+}
+
+// The factory flags are const. Pin them anyway.
+#[test]
+#[allow(clippy::assertions_on_constants)]
+fn factory_zone_is_four_pixels() {
+    assert!(SnapView::FACTORY.snap_to_guides);
+    assert!(!SnapView::FACTORY.snap_to_document_grid);
+    assert!(SnapView::FACTORY.smart_guides);
+    assert_eq!(SnapView::FACTORY.zone_px, 4.0);
+    assert!(!SnapView::OFF.any());
+    assert!(SnapView::FACTORY.any());
+}
+
+fn doc_with_items(moving: Rect, other: Rect, guide_x: f64) -> (Document, ItemId, ItemId) {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let make = |doc: &mut Document, rect: Rect| {
+        let id = ItemId(doc.alloc());
+        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(rect));
+        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+        id
+    };
+    let moving_id = make(&mut doc, moving);
+    let other_id = make(&mut doc, other);
+    let page = &mut Arc::make_mut(&mut doc.spreads[0]).pages[0];
+    page.guides.push(Guide { orientation: Orientation::Vertical, position: guide_x, spread: false, locked: false, layer: None, liquid: false });
+    (doc, moving_id, other_id)
+}
+
+fn ctx_on<'a>(doc: &'a Document, sel: &'a Selection, cache: &'a Cache, layout: &'a CanvasLayout) -> ToolContext<'a> {
+    ToolContext {
+        doc,
+        selection: sel,
+        cache,
+        layout,
+        zoom: 1.0,
+        layer: doc.default_layer(),
+        snap: SnapView::FACTORY,
+        unit: Unit::Points,
+        stroke_in_front: false,
+    }
+}
+
+fn y_req(rect: Rect) -> SnapRequest<'static> {
+    SnapRequest {
+        spread: SpreadRef::Doc(0),
+        gesture: Gesture::Move,
+        rect,
+        x_edges: [false, false, false],
+        y_edges: [true, true, true],
+        exclude: &[],
+        exclude_guides: &[],
+        copying: false,
+        lengths: [None, None],
+        angle: None,
+        radius: 0.0,
+        pointer: Point::new(0.0, 0.0),
+    }
+}
+
+fn move_req<'a>(rect: Rect, exclude: &'a [ItemId]) -> SnapRequest<'a> {
+    SnapRequest {
+        spread: SpreadRef::Doc(0),
+        gesture: Gesture::Move,
+        rect,
+        x_edges: [true, true, true],
+        y_edges: [false, false, false],
+        exclude,
+        exclude_guides: &[],
+        copying: false,
+        lengths: [None, None],
+        angle: None,
+        radius: 0.0,
+        pointer: Point::new(0.0, 0.0),
+    }
+}
+
+/// The bleed guide attracts like a ruler guide: a top edge 2 pt below the top bleed line
+/// snaps up to it; with no bleed there is nothing there to snap to.
+#[test]
+fn bleed_guide_is_a_snap_target() {
+    let far = Rect::new(300.0, 300.0, 320.0, 320.0);
+    for (bleed, expected) in [([9.0, 9.0, 9.0, 9.0], -2.0), ([0.0; 4], 0.0)] {
+        let (mut doc, moving, _other) = doc_with_items(Rect::new(80.0, 100.0, 100.0, 140.0), far, 500.0);
+        doc.settings.bleed = bleed;
+        let top = doc.spreads[0].bounds().y0 - 9.0;
+        let rect = Rect::new(80.0, top + 2.0, 100.0, top + 40.0);
+        let cache = Cache::new();
+        let layout = CanvasLayout::new(&doc, false);
+        let sel = Selection::default();
+        let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+        cx.snap.zone_px = 4.0;
+        let hit = snap(
+            &cx,
+            SnapRequest {
+                spread: SpreadRef::Doc(0),
+                gesture: Gesture::Move,
+                rect,
+                x_edges: [false, false, false],
+                y_edges: [true, true, true],
+                exclude: &[moving],
+                exclude_guides: &[],
+                copying: false,
+                lengths: [None, None],
+                angle: None,
+                radius: 0.0,
+                pointer: Point::new(0.0, 0.0),
+            },
+        );
+        assert!((hit.delta.y - expected).abs() < 1e-6, "bleed {bleed:?}: {:?}", hit.delta);
+    }
+}
+
+#[test]
+fn guide_beats_a_closer_object_edge() {
+    // Right edge at 100.5. Object edge at 100 (0.5 away). Guide at 104 (3.5 away). Zone is 4.
+    let (doc, moving, _other) = doc_with_items(Rect::new(80.0, 100.0, 100.5, 140.0), Rect::new(90.0, 100.0, 100.0, 160.0), 104.0);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.zone_px = 4.0;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(80.0, 100.0, 100.5, 140.0),
+            x_edges: [true, true, true],
+            y_edges: [false, false, false],
+            exclude: &[moving],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x - 3.5).abs() < 1e-6);
+    assert!(hit.guides.is_empty());
+}
+
+/// A dragged guide is not its own target: excluded, the guide at 104 doesn't pull a line at 102.
+/// Nor does the baseline grid pull it.
+#[test]
+fn excluded_guide_is_not_a_target() {
+    let far = Rect::new(400.0, 400.0, 420.0, 420.0);
+    let (doc, _, _) = doc_with_items(far, far, 104.0);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let cx = ctx_on(&doc, &sel, &cache, &layout);
+    let line = Rect::new(102.0, 100.0, 102.0, 300.0);
+    let dragged = [designcraft_doc::GuideSel { spread: SpreadRef::Doc(0), page: 0, index: 0 }];
+    let hit = snap(&cx, move_req(line, &[]));
+    assert!((hit.delta.x - 2.0).abs() < 1e-6, "{:?}", hit.delta);
+    let hit = snap(&cx, SnapRequest { exclude_guides: &dragged, ..move_req(line, &[]) });
+    assert_eq!(hit.delta.x, 0.0);
+    // A dragged guide passes the baseline grid's lines (36 + 12n), which a moved object meets.
+    let flat = Rect::new(100.0, 86.0, 300.0, 86.0);
+    assert!((snap(&cx, y_req(flat)).delta.y - -2.0).abs() < 1e-6);
+    assert_eq!(snap(&cx, SnapRequest { gesture: Gesture::Guide, ..y_req(flat) }).delta.y, 0.0);
+}
+
+#[test]
+fn parent_centered_stroke_attracts_at_the_outer_edge() {
+    let mut doc = Document::new(&NewDocument::default());
+    let pid = doc.add_parent("A", "A-Parent", 1, 12.0, Margins::uniform(36.0));
+    doc.apply_parent(&[0], Some(pid)).unwrap();
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let (ppi, ppg) = doc.parent_page_for(0).unwrap();
+    let parent_x = doc.parents[ppi].pages[ppg].x;
+    let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(parent_x + 72.0, 140.0, parent_x + 252.0, 300.0)));
+    item.stroke = Stroke::default(); // 1 pt, center
+    doc.insert_item(SpreadRef::Parent(ppi), item, None).unwrap();
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    // Moving left edge at 253. Visible parent right edge is 252.5.
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(253.0, 140.0, 353.0, 240.0),
+            x_edges: [true, false, false],
+            y_edges: [false, false, false],
+            exclude: &[],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x - -0.5).abs() < 1e-6, "delta {}", hit.delta.x);
+}
+
+#[test]
+fn object_edge_snaps_when_guide_snap_is_off() {
+    let (doc, moving, _other) = doc_with_items(Rect::new(80.0, 100.0, 100.5, 140.0), Rect::new(90.0, 100.0, 100.0, 160.0), 104.0);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(80.0, 100.0, 100.5, 140.0),
+            x_edges: [true, true, true],
+            y_edges: [false, false, false],
+            exclude: &[moving],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x - -0.5).abs() < 1e-6);
+    assert!(matches!(hit.guides.first(), Some(Overlay::Guide { .. })));
+}
+
+#[test]
+fn hidden_layer_guide_is_not_a_target() {
+    let (mut doc, moving, _) = doc_with_items(Rect::new(80.0, 100.0, 102.0, 140.0), Rect::new(300.0, 100.0, 340.0, 140.0), 104.0);
+    let layer = doc.default_layer();
+    doc.layers.iter_mut().find(|l| l.id == layer).unwrap().visible = false;
+    Arc::make_mut(&mut doc.spreads[0]).pages[0].guides[0].layer = Some(layer);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let cx = ctx_on(&doc, &sel, &cache, &layout);
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(80.0, 100.0, 102.0, 140.0),
+            x_edges: [false, false, true],
+            y_edges: [false, false, false],
+            exclude: &[moving],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert_eq!(hit.delta.x, 0.0);
+}
+
+#[test]
+fn alt_copy_snaps_to_the_original() {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(100.0, 40.0, 160.0, 80.0)));
+    doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(162.0, 40.0, 222.0, 80.0),
+            x_edges: [true, false, false],
+            y_edges: [false, false, false],
+            exclude: &[id],
+            exclude_guides: &[],
+            copying: true,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x - -2.0).abs() < 1e-6);
+}
+
+#[test]
+fn alt_copy_does_not_stick_to_the_preview() {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let make = |doc: &mut Document, rect: Rect| {
+        let id = ItemId(doc.alloc());
+        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(rect));
+        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+        id
+    };
+    let original = make(&mut doc, Rect::new(100.0, 40.0, 160.0, 80.0));
+    let ghost = make(&mut doc, Rect::new(161.0, 40.0, 221.0, 80.0));
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::items(vec![ghost]);
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(161.0, 40.0, 221.0, 80.0),
+            x_edges: [true, false, false],
+            y_edges: [false, false, false],
+            exclude: &[original],
+            exclude_guides: &[],
+            copying: true,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x - -1.0).abs() < 1e-6, "delta.x = {}", hit.delta.x);
+}
+
+#[test]
+fn parent_page_guides_snap_on_the_document_page() {
+    // Facing document: page 1 is a right page at x = 0; its parent page is A's right page at
+    // x = 612 in the parent spread.
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(80.0, 100.0, 100.5, 140.0)));
+    doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    Arc::make_mut(&mut doc.parents[0]).pages[1].guides.push(Guide {
+        orientation: Orientation::Vertical,
+        position: 612.0 + 104.0,
+        spread: false,
+        locked: false,
+        layer: None,
+        liquid: false,
+    });
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.zone_px = 4.0;
+    let hit = snap(&cx, move_req(Rect::new(80.0, 100.0, 100.5, 140.0), &[id]));
+    assert!((hit.delta.x - 3.5).abs() < 1e-6, "snaps to the parent guide at x = 104: {:?}", hit.delta);
+}
+
+#[test]
+fn grid_beats_a_closer_guide() {
+    let mut doc = Document::new(&NewDocument::default());
+    doc.settings.grid.horizontal = 72.0;
+    doc.settings.grid.vertical = 72.0;
+    doc.settings.grid.subdivisions = 8; // 9 pt
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(10.0, 10.0, 40.0, 40.0)));
+    doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    // Guide 1 pt away at x = 11. Subdivision line at 9 is 1 pt the other way. Grid must win.
+    Arc::make_mut(&mut doc.spreads[0]).pages[0].guides.push(Guide {
+        orientation: Orientation::Vertical,
+        position: 11.0,
+        spread: true,
+        locked: false,
+        layer: None,
+        liquid: false,
+    });
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_document_grid = true;
+    let hit = snap(&cx, move_req(Rect::new(10.0, 10.0, 40.0, 40.0), &[id]));
+    assert!((hit.delta.x - -1.0).abs() < 1e-6);
+    assert!(hit.guides.is_empty());
+}
+
+#[test]
+fn hidden_baseline_still_snaps_and_zero_increment_does_not() {
+    let mut doc = Document::new(&NewDocument::default());
+    doc.settings.baseline_grid.start = 36.0;
+    doc.settings.baseline_grid.increment = 12.0;
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let cx = ctx_on(&doc, &sel, &cache, &layout);
+    // Top at 49 wants the line at 48 (start 36, increment 12). The margin at 36 is 13 pt away.
+    let hit = snap(&cx, y_req(Rect::new(100.0, 49.0, 140.0, 80.0)));
+    assert!((hit.delta.y - -1.0).abs() < 1e-6);
+    let mut dead = doc.clone();
+    dead.settings.baseline_grid.increment = 0.0;
+    let layout = CanvasLayout::new(&dead, false);
+    let cx = ctx_on(&dead, &sel, &cache, &layout);
+    let hit = snap(&cx, y_req(Rect::new(100.0, 49.0, 140.0, 80.0)));
+    assert_eq!(hit.delta.y, 0.0);
+}
+
+#[test]
+fn baseline_relative_to_the_top_margin_snaps_from_the_margin() {
+    let mut doc = Document::new(&NewDocument::default());
+    std::sync::Arc::make_mut(&mut doc.spreads[0]).pages[0].margins.top = 37.0;
+    doc.settings.baseline_grid.start = 0.0;
+    doc.settings.baseline_grid.increment = 10.0;
+    doc.settings.baseline_grid.relative_to = designcraft_doc::GridRelative::TopMargin;
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let cx = ctx_on(&doc, &sel, &cache, &layout);
+    // Lines at 37 + 10n: a top at 58 goes up to 57, not down to the page-relative 60.
+    let hit = snap(&cx, y_req(Rect::new(100.0, 58.0, 140.0, 80.0)));
+    assert!((hit.delta.y - -1.0).abs() < 1e-6, "{}", hit.delta.y);
+}
+
+#[test]
+fn nearer_of_margin_and_baseline_wins() {
+    // Bottom margin at 792 - 54 = 738, between baseline lines 732 and 744.
+    let doc = Document::new(&NewDocument {
+        margins: designcraft_doc::Margins { top: 54.0, bottom: 54.0, inside: 54.0, outside: 42.0 },
+        ..Default::default()
+    });
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    // At 50% the 4 px zone is 8 pt: both the margin and a baseline line are in reach.
+    let cx = ToolContext { zoom: 0.5, ..ctx_on(&doc, &sel, &cache, &layout) };
+    let bottom = |y1: f64| SnapRequest { y_edges: [false, false, true], gesture: Gesture::Resize, ..y_req(Rect::new(100.0, 600.0, 140.0, y1)) };
+    assert!((snap(&cx, bottom(739.5)).delta.y - -1.5).abs() < 1e-6, "the margin is nearer");
+    assert!((snap(&cx, bottom(742.5)).delta.y - 1.5).abs() < 1e-6, "the baseline line is nearer");
+    assert!((snap(&cx, bottom(741.0)).delta.y - -3.0).abs() < 1e-6, "a tie goes to the margin");
+}
+
+#[test]
+fn rotated_item_matches_its_own_side() {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 200.0, 40.0)));
+    item.xf = Affine::rotate((-30.0_f64).to_radians());
+    doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    cx.snap.snap_to_document_grid = false;
+    // Width 193.2 is the axis-aligned box. 200 is the side. Zone 4 reaches 200 from 197, not from 193.
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Resize,
+            rect: Rect::new(80.0, 200.0, 277.0, 280.0),
+            x_edges: [false, false, true],
+            y_edges: [false, false, false],
+            exclude: &[],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [Some(197.0), None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(277.0, 240.0),
+        },
+    );
+    assert!((hit.delta.x - 3.0).abs() < 1e-6);
+    assert!(matches!(hit.guides.last(), Some(Overlay::Measure { text, .. }) if text.contains("200")));
+}
+
+#[test]
+fn grouped_child_matches_spread_side() {
+    // Group scale 2 on X and 1 on Y. Child rotated -90 degrees (decompose reports +90).
+    // Spread-space sides are local width times 1 (100) and local height times 2 (80).
+    // 82 is 2 pt from 80 and far from 200, which is what per-node scales would offer.
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let child_id = ItemId(doc.alloc());
+    let mut child = Item::new(child_id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 100.0, 40.0)));
+    child.xf = Affine::rotate((-90.0_f64).to_radians());
+    let group_id = ItemId(doc.alloc());
+    let mut group = Item::new(group_id, layer, Shape::Group, designcraft_geom::PathData::default());
+    group.xf = Affine::scale_non_uniform(2.0, 1.0);
+    group.content = designcraft_doc::Content::Group { items: vec![std::sync::Arc::new(child)] };
+    doc.insert_item(SpreadRef::Doc(0), group, None).unwrap();
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    cx.snap.snap_to_document_grid = false;
+    cx.snap.align_edges = false;
+    cx.snap.align_centers = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Resize,
+            rect: Rect::new(200.0, 200.0, 282.0, 240.0),
+            x_edges: [false, false, true],
+            y_edges: [false, false, false],
+            exclude: &[],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [Some(82.0), None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(282.0, 220.0),
+        },
+    );
+    assert!((hit.delta.x - -2.0).abs() < 1e-6, "delta.x = {}, want -2 toward local height times 2", hit.delta.x);
+}
+
+#[test]
+fn move_matches_a_stationary_gap() {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    // Stationary gap of 20 between [0,40] and [60,90]. Moving box at [112,150], 22 away from 90.
+    for r in [Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(60.0, 0.0, 90.0, 30.0), Rect::new(112.0, 0.0, 150.0, 30.0)] {
+        let id = ItemId(doc.alloc());
+        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(r));
+        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    }
+    let moving = doc.spreads[0].items[2].id;
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Move,
+            rect: Rect::new(112.0, 0.0, 150.0, 30.0),
+            x_edges: [true, true, true],
+            y_edges: [false, false, false],
+            exclude: &[moving],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x - -2.0).abs() < 1e-6);
+    assert!(hit.guides.iter().any(|g| matches!(g, Overlay::Gap { .. })));
+}
+
+fn doc_with_rects(rects: &[Rect]) -> Document {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    for &r in rects {
+        let id = ItemId(doc.alloc());
+        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(r));
+        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    }
+    doc
+}
+
+fn gap_overlays(guides: &[Overlay]) -> usize {
+    guides.iter().filter(|g| matches!(g, Overlay::Gap { .. })).count()
+}
+
+// #188: a box dragged between two others snaps to the middle and marks both gaps.
+#[test]
+fn move_centers_between_two_boxes_side_by_side() {
+    // Neighbours end at 40 and start at 160. The 30 wide mover at [83,113] is 2 left of centre.
+    let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(160.0, 0.0, 200.0, 30.0)]);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(&cx, move_req(Rect::new(83.0, 5.0, 113.0, 25.0), &[]));
+    assert!((hit.delta.x - 2.0).abs() < 1e-6, "{}", hit.delta.x);
+    assert_eq!(gap_overlays(&hit.guides), 2);
+}
+
+#[test]
+fn move_centers_between_two_boxes_stacked() {
+    let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 30.0, 40.0), Rect::new(0.0, 160.0, 30.0, 200.0)]);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(&cx, y_req(Rect::new(5.0, 83.0, 25.0, 113.0)));
+    assert!((hit.delta.y - 2.0).abs() < 1e-6, "{}", hit.delta.y);
+    assert_eq!(gap_overlays(&hit.guides), 2);
+}
+
+fn with_baseline_grid(mut doc: Document) -> Document {
+    doc.settings.baseline_grid.start = 36.0;
+    doc.settings.baseline_grid.increment = 12.0;
+    doc
+}
+
+// #188: with Snap to Guides on, the hidden baseline grid took vertical moves first.
+#[test]
+fn vertical_centering_beats_a_closer_baseline() {
+    // Middle at 200. Mover centre 198 (+2). Its top and bottom are 3 from lines 180 and 216.
+    let doc = with_baseline_grid(doc_with_rects(&[Rect::new(100.0, 100.0, 130.0, 140.0), Rect::new(100.0, 260.0, 130.0, 300.0)]));
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let cx = ctx_on(&doc, &sel, &cache, &layout);
+    let hit = snap(&cx, y_req(Rect::new(105.0, 183.0, 125.0, 213.0)));
+    assert!((hit.delta.y - 2.0).abs() < 1e-6, "{}", hit.delta.y);
+    assert_eq!(gap_overlays(&hit.guides), 2);
+}
+
+#[test]
+fn vertical_alignment_beats_a_closer_baseline() {
+    // Top 107 is 1 from the line at 108 and 2 from the other box's top at 105.
+    let doc = with_baseline_grid(doc_with_rects(&[Rect::new(300.0, 105.0, 340.0, 135.0)]));
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let cx = ctx_on(&doc, &sel, &cache, &layout);
+    let hit = snap(&cx, y_req(Rect::new(100.0, 107.0, 140.0, 137.0)));
+    assert!((hit.delta.y - -2.0).abs() < 1e-6, "{}", hit.delta.y);
+    assert!(hit.guides.iter().any(|g| matches!(g, Overlay::Guide { .. })));
+}
+
+#[test]
+fn move_off_center_outside_the_zone_does_not_center() {
+    // 10 off centre, zone 4.
+    let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(160.0, 0.0, 200.0, 30.0)]);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(&cx, move_req(Rect::new(95.0, 5.0, 125.0, 25.0), &[]));
+    assert_eq!(hit.delta.x, 0.0);
+    assert_eq!(gap_overlays(&hit.guides), 0);
+}
+
+#[test]
+fn centering_needs_smart_spacing() {
+    let doc = doc_with_rects(&[Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(160.0, 0.0, 200.0, 30.0)]);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    cx.snap.smart_spacing = false;
+    let hit = snap(&cx, move_req(Rect::new(83.0, 5.0, 113.0, 25.0), &[]));
+    assert_eq!(hit.delta.x, 0.0);
+}
+
+#[test]
+fn create_does_not_match_spacing() {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    for r in [Rect::new(0.0, 0.0, 40.0, 30.0), Rect::new(60.0, 0.0, 90.0, 30.0)] {
+        let id = ItemId(doc.alloc());
+        let item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(r));
+        doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    }
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    cx.snap.smart_dimensions = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Create,
+            rect: Rect::new(112.0, 0.0, 150.0, 30.0),
+            x_edges: [true, true, true],
+            y_edges: [false, false, false],
+            exclude: &[],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [Some(38.0), None],
+            angle: None,
+            radius: 0.0,
+            pointer: Point::new(0.0, 0.0),
+        },
+    );
+    assert!((hit.delta.x).abs() < 1e-6);
+}
+
+#[test]
+fn rotation_matches_another_items_angle() {
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 80.0, 40.0)));
+    item.xf = Affine::rotate((-30.0_f64).to_radians());
+    doc.insert_item(SpreadRef::Doc(0), item, None).unwrap();
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Rotate,
+            rect: Rect::new(100.0, 100.0, 160.0, 140.0),
+            x_edges: [false, false, false],
+            y_edges: [false, false, false],
+            exclude: &[],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: Some(28.0),
+            radius: 80.0,
+            pointer: Point::new(180.0, 120.0),
+        },
+    );
+    let angle = hit.angle.expect("rotation hit");
+    assert!((angle - 30.0).abs() < 1e-6);
+    assert!(matches!(hit.guides.first(), Some(Overlay::Measure { .. })));
+}
+
+#[test]
+fn parent_item_angle_matches() {
+    // Document::new already has A-Parent. Apply a second parent and insert on the
+    // page parent_page_for shows, not Parent(0). A facing right page sits near x 612.
+    let mut doc = Document::new(&NewDocument::default());
+    let pid = doc.add_parent("B", "B-Parent", 1, 12.0, Margins::uniform(36.0));
+    doc.apply_parent(&[0], Some(pid)).unwrap();
+    std::sync::Arc::make_mut(&mut doc.spreads[0]).pages[0].show_parent_items = true;
+    let (ppi, ppg) = doc.parent_page_for(0).unwrap();
+    let parent_x = doc.parents[ppi].pages[ppg].x;
+    let rect = Rect::new(parent_x + 72.0, 140.0, parent_x + 152.0, 180.0);
+    let center = rect.center();
+    let layer = doc.default_layer();
+    let id = ItemId(doc.alloc());
+    let mut item = Item::new(id, layer, Shape::Rectangle, shapes::rectangle(rect));
+    item.xf = Affine::translate((center.x, center.y)) * Affine::rotate((-30.0_f64).to_radians()) * Affine::translate((-center.x, -center.y));
+    doc.insert_item(SpreadRef::Parent(ppi), item, None).unwrap();
+    assert!(doc.spreads[0].items.iter().all(|it| (designcraft_geom::decompose::decompose(it.xf).rotation - 30.0).abs() > 1.0));
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let hit = snap(
+        &cx,
+        SnapRequest {
+            spread: SpreadRef::Doc(0),
+            gesture: Gesture::Rotate,
+            rect: Rect::new(100.0, 100.0, 160.0, 140.0),
+            x_edges: [false, false, false],
+            y_edges: [false, false, false],
+            exclude: &[],
+            exclude_guides: &[],
+            copying: false,
+            lengths: [None, None],
+            angle: Some(28.0),
+            radius: 80.0,
+            pointer: Point::new(180.0, 120.0),
+        },
+    );
+    let angle = hit.angle.expect("parent rotation hit");
+    assert!((angle - 30.0).abs() < 1e-6);
+}
+
+#[test]
+fn rotated_group_uses_the_per_child_union() {
+    // Two children do not fill their local union. Rotating that union as one rectangle
+    // swings the empty corners out. The snap target is each child's visible box, transformed, then united.
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let mut child_a = Item::new(ItemId(doc.alloc()), layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 10.0, 10.0)));
+    child_a.stroke = Stroke { weight: 2.0, ..Stroke::default() };
+    let child_b = Item::new(ItemId(doc.alloc()), layer, Shape::Rectangle, shapes::rectangle(Rect::new(40.0, 30.0, 50.0, 40.0)));
+    let mut group = Item::new(ItemId(doc.alloc()), layer, Shape::Group, designcraft_geom::PathData::default());
+    let xf = Affine::translate((300.0, 400.0)) * Affine::rotate((-45.0_f64).to_radians());
+    group.xf = xf;
+    group.content = designcraft_doc::Content::Group { items: vec![Arc::new(child_a), Arc::new(child_b)] };
+    doc.insert_item(SpreadRef::Doc(0), group, None).unwrap();
+    let a_vis = Rect::new(-1.0, -1.0, 11.0, 11.0);
+    let b_vis = Rect::new(40.0, 30.0, 50.0, 40.0);
+    let per_child = xf.transform_rect_bbox(a_vis).union(xf.transform_rect_bbox(b_vis));
+    let rotated_union = xf.transform_rect_bbox(a_vis.union(b_vis));
+    // At 45 degrees the empty corners move y, not x. The two boxes share x0.
+    assert!((per_child.y0 - rotated_union.y0).abs() > 1.0, "fixture does not separate the two boxes");
+    let gap = 2.0;
+    // A short rect just above the per-child top. Its other edges stay outside the zone of the rotated union.
+    let moving = Rect::new(per_child.x0, per_child.y0 - gap - 4.0, per_child.x0 + 20.0, per_child.y0 - gap);
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    cx.snap.snap_to_document_grid = false;
+    let hit = snap(&cx, y_req(moving));
+    assert!((hit.delta.y - gap).abs() < 1e-4, "delta.y {}, want {gap} onto {}", hit.delta.y, per_child.y0);
+    let wrong = rotated_union.y0 - moving.y1;
+    assert!((hit.delta.y - wrong).abs() > 1.0, "delta matched the rotated local union");
+}
+
+#[test]
+fn rotated_group_child_does_not_offer_local_zero() {
+    // The group is at 30 degrees. Its child stays at local 0, so the absolute angle is 30.
+    // 2 degrees is inside the zone of 0 and far from 30. Local 0 must not win.
+    let mut doc = Document::new(&NewDocument::default());
+    let layer = doc.default_layer();
+    let child = Item::new(ItemId(doc.alloc()), layer, Shape::Rectangle, shapes::rectangle(Rect::new(0.0, 0.0, 40.0, 20.0)));
+    let mut group = Item::new(ItemId(doc.alloc()), layer, Shape::Group, designcraft_geom::PathData::default());
+    group.xf = Affine::rotate((-30.0_f64).to_radians());
+    group.content = designcraft_doc::Content::Group { items: vec![Arc::new(child)] };
+    doc.insert_item(SpreadRef::Doc(0), group, None).unwrap();
+    let cache = Cache::new();
+    let layout = CanvasLayout::new(&doc, false);
+    let sel = Selection::default();
+    let mut cx = ctx_on(&doc, &sel, &cache, &layout);
+    cx.snap.snap_to_guides = false;
+    let ask = |angle: f64| {
+        snap(
+            &cx,
+            SnapRequest {
+                spread: SpreadRef::Doc(0),
+                gesture: Gesture::Rotate,
+                rect: Rect::new(100.0, 100.0, 160.0, 140.0),
+                x_edges: [false, false, false],
+                y_edges: [false, false, false],
+                exclude: &[],
+                exclude_guides: &[],
+                copying: false,
+                lengths: [None, None],
+                angle: Some(angle),
+                radius: 80.0,
+                pointer: Point::new(180.0, 120.0),
+            },
+        )
+    };
+    let near_zero = ask(2.0);
+    assert!(near_zero.angle.is_none(), "local 0 was a target: {:?}", near_zero.angle);
+    let near_group = ask(28.0);
+    let angle = near_group.angle.expect("absolute 30");
+    assert!((angle - 30.0).abs() < 1e-6, "angle {angle}");
+}