diff --git a/crates/ui-egui/src/dialogs/find_links.rs b/crates/ui-egui/src/dialogs/find_links.rs
index 415cf3a8e..6543816ec 100644
--- a/crates/ui-egui/src/dialogs/find_links.rs
+++ b/crates/ui-egui/src/dialogs/find_links.rs
@@ -384,339 +384,4 @@ fn confirm(app: &mut VectorcraftApp, d: &Dialog) -> Result<Value, String> {
 }
 
 #[cfg(test)]
-mod tests {
-    use std::path::{Path, PathBuf};
-    use std::time::Instant;
-
-    use vectorcraft_engine::Session;
-    use vectorcraft_engine::cmd::findfiles::Rules;
-
-    use super::*;
-
-    fn frame(app: &mut VectorcraftApp) -> String {
-        crate::tests_labels::painted_text(app, |app, ui| super::super::show(app, ui.ctx()))
-    }
-
-    /// A fresh temporary folder (canonical, as a search reports it).
-    fn folder(tag: &str) -> PathBuf {
-        let dir = vectorcraft_testkit::temp_dir(&format!("find-links-{tag}"));
-        let _ = std::fs::remove_dir_all(&dir);
-        std::fs::create_dir_all(&dir).unwrap();
-        vectorcraft_engine::cmd::findfiles::plain(std::fs::canonicalize(&dir).unwrap())
-    }
-
-    /// An app that reads files, shows a folder picker and whose searches may go anywhere in `root`,
-    /// on two threads.
-    fn app_for(root: &Path) -> VectorcraftApp {
-        let mut app = VectorcraftApp::new(Session::new(), Default::default());
-        app.services.read = Some(Box::new(|p: &str| std::fs::read(p).map_err(|e| e.to_string())));
-        app.services.pick_folder = Some(Box::new(|| None));
-        app.session.search_rules = Some(Rules { user_content: vec![root.to_path_buf()], ..Rules::default() });
-        app.session.search_threads = Some(2);
-        app
-    }
-
-    /// `rel` (`/`-separated) inside `root`, with the platform's separators, as the app reports paths.
-    fn at(root: &Path, rel: &str) -> PathBuf {
-        rel.split('/').fold(root.to_path_buf(), |p, c| p.join(c))
-    }
-
-    fn write(path: &Path, bytes: &[u8]) {
-        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
-        std::fs::write(path, bytes).unwrap();
-    }
-
-    /// A PNG of one color, a different one for each `n`.
-    fn png(n: u8) -> Vec<u8> {
-        let mut out = vec![];
-        image::RgbaImage::from_pixel(40, 30, image::Rgba([200, n.wrapping_mul(40), 0, 255]))
-            .write_to(&mut std::io::Cursor::new(&mut out), image::ImageFormat::Png)
-            .unwrap();
-        out
-    }
-
-    /// A document linking to files `names` in `root/orig`, saved as `root/doc/doc.vectorcraft`; the
-    /// files are then deleted and the document opened again → each file's bytes.
-    fn opened_without(app: &mut VectorcraftApp, root: &Path, names: &[&str]) -> Vec<Vec<u8>> {
-        app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
-        let mut files = vec![];
-        for (n, name) in (0..).zip(names) {
-            let path = root.join("orig").join(name);
-            write(&path, &png(n));
-            app.run("file.place", json!({"path": path})).unwrap();
-            files.push(png(n));
-        }
-        let doc = at(root, "doc/doc.vectorcraft");
-        std::fs::create_dir_all(doc.parent().unwrap()).unwrap();
-        app.run("document.save", json!({"path": doc})).unwrap();
-        std::fs::remove_dir_all(root.join("orig")).unwrap();
-        crate::io::open_path(app, &doc.to_string_lossy()).unwrap();
-        files
-    }
-
-    /// Draw the dialog until its search ends (10 seconds at most).
-    fn searched(app: &mut VectorcraftApp) {
-        let until = Instant::now() + Duration::from_secs(10);
-        while app.ui.dialog.as_ref().is_some_and(|d| d.str("state") == "searching") && Instant::now() < until {
-            frame(app);
-            std::thread::sleep(Duration::from_millis(5));
-        }
-    }
-
-    fn kind(app: &VectorcraftApp) -> Option<&str> {
-        app.ui.dialog.as_ref().map(|d| d.kind.as_str())
-    }
-
-    /// The pick of the row named `name`.
-    fn pick<'a>(d: &'a Dialog, name: &str) -> &'a Value {
-        let i = d.fields["missing"].as_array().unwrap().iter().position(|r| r["name"] == name).unwrap();
-        &d.fields["picks"][i]
-    }
-
-    /// Find in Folder… in Linked File Not Found: each missing file's same file is chosen, and Relink
-    /// relinks them.
-    #[test]
-    fn find_in_folder_relinks_the_missing_files_to_the_files_found() {
-        let root = folder("relink");
-        let mut app = app_for(&root);
-        let bytes = opened_without(&mut app, &root, &["a.png", "b.png"]);
-        assert_eq!(kind(&app), Some(super::super::missing_links::KIND));
-        assert!(frame(&mut app).contains("Find in Folder…"));
-        let (a, b) = (at(&root, "found/sub/a.png"), at(&root, "found/b.png"));
-        write(&a, &bytes[0]);
-        write(&b, &bytes[1]);
-        write(&at(&root, "found/other/b.png"), b"another file");
-        // What Find in Folder… does with the folder picked.
-        app.ui.dialog.as_mut().unwrap().fields.insert("searchFolder".into(), json!(root.join("found")));
-        let r = super::super::confirm(&mut app).unwrap();
-        assert!(matches!(r["state"].as_str(), Some("searching" | "done")), "{r}");
-        assert_eq!(kind(&app), Some(KIND));
-        searched(&mut app);
-        let d = app.ui.dialog.as_ref().unwrap();
-        assert_eq!((d.str("state"), pick(d, "a.png"), pick(d, "b.png")), ("done".to_string(), &json!(a), &json!(b)));
-        let text = frame(&mut app);
-        for label in
-            ["Find Linked Files", "a.png", "b.png", "Same file", "Don't Relink", "Find in Folder…", "Copy into the document's folder", "Relink"]
-        {
-            assert!(text.contains(label), "{label} in {text}");
-        }
-        super::super::confirm(&mut app).unwrap();
-        assert!(app.ui.dialog.is_none());
-        assert_eq!(app.ui.status, "Relinked 2 image(s)");
-        assert_eq!(app.run("links.check", json!({})).unwrap()["missing"], 0);
-    }
-
-    /// The files left without a file, or whose file fails to relink, go back to Linked File Not
-    /// Found; the failure is named in the status line, and the other files still relink.
-    #[test]
-    fn files_not_relinked_go_back_to_linked_file_not_found() {
-        let root = folder("back");
-        let mut app = app_for(&root);
-        let bytes = opened_without(&mut app, &root, &["a.png", "b.png", "c.png"]);
-        write(&at(&root, "found/a.png"), &bytes[0]);
-        write(&at(&root, "found/b.png"), b"not an image");
-        app.ui.dialog.as_mut().unwrap().fields.insert("searchFolder".into(), json!(root.join("found")));
-        super::super::confirm(&mut app).unwrap();
-        searched(&mut app);
-        let d = app.ui.dialog.as_ref().unwrap();
-        // b.png's only file is chosen, c.png has none.
-        assert_eq!((pick(d, "b.png"), pick(d, "c.png")), (&json!(at(&root, "found/b.png")), &Value::Null));
-        assert!(frame(&mut app).contains("Not found"));
-        super::super::confirm(&mut app).unwrap();
-        assert!(app.ui.status.starts_with("Relinked 1 image(s); b.png couldn't be relinked: "), "{}", app.ui.status);
-        let d = app.ui.dialog.as_ref().expect("Linked File Not Found again");
-        let names: Vec<&str> = d.fields["missing"].as_array().unwrap().iter().map(|r| r["name"].as_str().unwrap()).collect();
-        assert_eq!((d.kind.as_str(), names.len()), (super::super::missing_links::KIND, 2));
-        assert!(names.contains(&"b.png") && names.contains(&"c.png"), "{names:?}");
-        super::super::cancel(&mut app);
-        assert_eq!(app.run("links.check", json!({})).unwrap()["missing"], 2);
-    }
-
-    /// A file is chosen when the choice is clear: the only same file, else the only file. A row the
-    /// user chose for keeps its choice as the search goes on.
-    #[test]
-    fn a_file_is_chosen_only_when_the_choice_is_clear() {
-        let row = |p: &str| json!({"name": "a.png", "path": p, "ids": [1]});
-        let mut d = Dialog::new(KIND, json!({"missing": [row("/x/a.png"), row("/y/a.png"), row("/z/a.png")], "picks": [], "touched": []}));
-        let file = |p: &str, m: &str| json!({"path": p, "match": m});
-        let answer = |y: Vec<Value>| {
-            json!({"state": "searching", "links": [
-                {"path": "/x/a.png", "ids": [1], "files": [file("/f/a.png", "same"), file("/g/a.png", "name")]},
-                {"path": "/y/a.png", "ids": [1], "files": y},
-                {"path": "/z/a.png", "ids": [1], "files": [file("/f/a.png", "size"), file("/g/a.png", "name")]},
-            ]})
-        };
-        update(&mut d, &answer(vec![file("/f/a.png", "name")]));
-        assert_eq!(d.fields["picks"], json!(["/f/a.png", "/f/a.png", null]));
-        // Don't Relink chosen for the first row: the next answer leaves it, and the second row has
-        // two files now.
-        d.fields.insert("picks".into(), json!([null, "/f/a.png", null]));
-        d.fields.insert("touched".into(), json!([0]));
-        update(&mut d, &answer(vec![file("/f/a.png", "name"), file("/g/a.png", "name")]));
-        assert_eq!(d.fields["picks"], json!([null, null, null]));
-    }
-
-    /// A search of another folder starts the choices over: a file chosen from the last folder's
-    /// results isn't kept.
-    #[test]
-    fn another_folder_starts_the_choices_over() {
-        let root = folder("again");
-        let mut app = app_for(&root);
-        opened_without(&mut app, &root, &["a.png"]);
-        super::super::cancel(&mut app);
-        // Two files of the name and neither the same file: the search reads both folders.
-        write(&at(&root, "one/a.png"), b"one file");
-        write(&at(&root, "one/x/a.png"), b"another file");
-        std::fs::create_dir_all(root.join("two")).unwrap();
-        app.run("ui.findLinksInFolder", json!({"folder": root.join("one")})).unwrap();
-        searched(&mut app);
-        assert_eq!(app.ui.dialog.as_ref().unwrap().fields["found"][0]["files"].as_array().map(Vec::len), Some(2));
-        // The second file chosen, then another folder searched, which has no file of the name.
-        let d = app.ui.dialog.as_mut().unwrap();
-        d.fields.insert("picks".into(), json!([at(&root, "one/x/a.png")]));
-        d.fields.insert("touched".into(), json!([0]));
-        d.fields.insert("searchFolder".into(), json!(root.join("two")));
-        super::super::confirm(&mut app).unwrap();
-        searched(&mut app);
-        let d = app.ui.dialog.as_ref().unwrap();
-        assert_eq!((pick(d, "a.png"), &d.fields["touched"]), (&Value::Null, &json!([])));
-    }
-
-    #[test]
-    fn cancel_closes_the_dialog_and_stops_its_search() {
-        let root = folder("cancel");
-        // Enough folders that the search usually still runs when the dialog closes.
-        for a in 0..40 {
-            for b in 0..40 {
-                std::fs::create_dir_all(root.join(format!("tree/f{a}/g{b}"))).unwrap();
-            }
-        }
-        let mut app = app_for(&root);
-        app.session.search_threads = Some(1);
-        opened_without(&mut app, &root, &["a.png"]);
-        super::super::cancel(&mut app);
-        app.run("ui.findLinksInFolder", json!({"folder": root.join("tree")})).unwrap();
-        let id = app.ui.links_search.expect("the dialog's search");
-        assert_eq!((kind(&app), app.ui.dialog.as_ref().unwrap().bool("back")), (Some(KIND), false));
-        super::super::cancel(&mut app);
-        assert!(app.ui.dialog.is_none() && app.ui.links_search.is_none());
-        // Stopped by the close, unless the walker finished the folders first.
-        let r = app.session.execute("links.findFiles", &json!({})).unwrap();
-        assert_eq!(r["id"].as_u64(), Some(id), "{r}");
-        match r["state"].as_str() {
-            Some("stopped") => assert_eq!(r["stopped"], "stop", "{r}"),
-            state => assert_eq!(state, Some("done"), "{r}"),
-        }
-    }
-
-    /// Copy into the document's folder, for a saved document: the file is copied there first.
-    #[test]
-    fn copy_into_the_documents_folder_copies_before_relinking() {
-        let root = folder("copy");
-        let mut app = app_for(&root);
-        let bytes = opened_without(&mut app, &root, &["a.png"]);
-        super::super::cancel(&mut app);
-        write(&at(&root, "found/a.png"), &bytes[0]);
-        app.run("ui.findLinksInFolder", json!({"folder": root.join("found")})).unwrap();
-        searched(&mut app);
-        assert!(frame(&mut app).contains("Copy into the document's folder"));
-        app.ui.dialog.as_mut().unwrap().fields.insert("copy".into(), json!(true));
-        let r = super::super::confirm(&mut app).unwrap();
-        assert_eq!((r["relinked"].as_array().unwrap().len(), app.ui.dialog.is_none()), (1, true), "{r}");
-        let copy = at(&root, "doc/a.png");
-        assert_eq!(std::fs::read(&copy).unwrap(), bytes[0]);
-        let c = app.run("links.check", json!({})).unwrap();
-        assert_eq!((c["missing"].as_u64(), c["links"][0]["path"].as_str()), (Some(0), Some(&*copy.to_string_lossy())), "{c}");
-        // An unsaved document has no folder to copy into.
-        app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
-        let id = app.run("file.place", json!({"path": at(&root, "found/a.png")})).unwrap()["ids"][0].clone();
-        app.run("select.set", json!({"ids": [id]})).unwrap();
-        app.run("ui.findLinksInFolder", json!({"folder": root.join("found")})).unwrap();
-        searched(&mut app);
-        assert!(!frame(&mut app).contains("Copy into the document's folder"));
-    }
-
-    /// With Copy into the document's folder, a placed document is relinked where its file is.
-    #[test]
-    fn copy_leaves_placed_documents_where_they_are() {
-        let root = folder("placed");
-        let mut app = app_for(&root);
-        app.run("file.new", json!({"width": 100, "height": 100})).unwrap();
-        app.run("shape.rectangle", json!({"x": 10, "y": 10, "width": 50, "height": 50})).unwrap();
-        let badge = at(&root, "orig/badge.vectorcraft");
-        std::fs::create_dir_all(badge.parent().unwrap()).unwrap();
-        app.run("document.save", json!({"path": badge})).unwrap();
-        let found = at(&root, "found/badge.vectorcraft");
-        write(&found, &std::fs::read(&badge).unwrap());
-        app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
-        app.run("file.place", json!({"path": badge, "link": true})).unwrap();
-        let doc = at(&root, "doc/doc.vectorcraft");
-        std::fs::create_dir_all(doc.parent().unwrap()).unwrap();
-        app.run("document.save", json!({"path": doc})).unwrap();
-        std::fs::remove_dir_all(root.join("orig")).unwrap();
-        crate::io::open_path(&mut app, &doc.to_string_lossy()).unwrap();
-        super::super::cancel(&mut app);
-        app.run("ui.findLinksInFolder", json!({"folder": root.join("found")})).unwrap();
-        searched(&mut app);
-        app.ui.dialog.as_mut().unwrap().fields.insert("copy".into(), json!(true));
-        let r = super::super::confirm(&mut app).unwrap();
-        assert_eq!((r["relinked"].as_array().unwrap().len(), &r["failed"]), (1, &json!([])), "{r}");
-        assert!(!at(&root, "doc/badge.vectorcraft").exists());
-        assert_eq!(app.run("links.check", json!({})).unwrap()["links"][0]["path"], json!(found));
-    }
-
-    /// The Links panel's Find in Folder… (`ui.findLinksInFolder`): the selected linked files, else
-    /// the missing ones, in a folder the user picks.
-    #[test]
-    fn the_links_panel_looks_for_the_selected_or_the_missing_files() {
-        let root = folder("panel");
-        let mut app = app_for(&root);
-        app.services.pick_folder = None;
-        app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
-        assert!(!crate::menus::enabled(&app, "ui.findLinksInFolder"), "no folder picker (the web)");
-        let picked = root.join("found").to_string_lossy().into_owned();
-        let answer = picked.clone();
-        app.services.pick_folder = Some(Box::new(move || Some(answer.clone())));
-        assert!(crate::menus::enabled(&app, "ui.findLinksInFolder"));
-        // Nothing to look for: no folder is asked for.
-        assert_eq!(app.run("ui.findLinksInFolder", json!({})).err().as_deref(), Some("No linked files to look for"));
-        let here = at(&root, "found/here.png");
-        write(&here, &png(1));
-        let id = app.run("file.place", json!({"path": here})).unwrap()["ids"][0].clone();
-        app.run("select.set", json!({"ids": [id]})).unwrap();
-        let menu = crate::tests_labels::painted_text(&mut app, crate::panels::links::menu);
-        assert!(menu.contains("Find in Folder…"), "{menu}");
-        app.run("ui.findLinksInFolder", json!({})).unwrap();
-        let d = app.ui.dialog.as_ref().unwrap();
-        assert_eq!((d.kind.as_str(), d.fields["missing"][0]["name"].as_str(), d.str("folder")), (KIND, Some("here.png"), picked));
-        // here.png isn't missing: the dialog asks about linked files.
-        assert!(frame(&mut app).contains("Choose the file to relink each linked file to."));
-        searched(&mut app);
-        assert_eq!(pick(app.ui.dialog.as_ref().unwrap(), "here.png"), &json!(here));
-    }
-
-    /// The Links panel's Find in Folder… asks for the folder off the UI thread (#867): Find Linked
-    /// Files opens on the folder when the folder picker answers.
-    #[test]
-    fn find_in_folder_asks_for_the_folder_off_the_ui_thread() {
-        let root = folder("later");
-        let mut app = app_for(&root);
-        let (shown, _) = crate::tests_picks::off_the_ui_thread(&mut app.services);
-        app.services.read = Some(Box::new(|p: &str| std::fs::read(p).map_err(|e| e.to_string())));
-        app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
-        let here = at(&root, "found/here.png");
-        write(&here, &png(1));
-        let id = app.run("file.place", json!({"path": here})).unwrap()["ids"][0].clone();
-        app.run("select.set", json!({"ids": [id]})).unwrap();
-        // Nothing opens until the picker answers.
-        assert!(app.run("ui.findLinksInFolder", json!({})).is_err());
-        assert_eq!((shown.requests(), kind(&app)), (vec![PickRequest::Folder], None));
-        let found = root.join("found").to_string_lossy().into_owned();
-        shown.answer(&[found.as_str()]);
-        crate::picks::poll(&mut app, &egui::Context::default());
-        let d = app.ui.dialog.as_ref().expect("Find Linked Files");
-        assert_eq!((d.kind.as_str(), d.str("folder")), (KIND, found));
-        searched(&mut app);
-        assert_eq!(pick(app.ui.dialog.as_ref().unwrap(), "here.png"), &json!(here));
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/dialogs/find_links/tests.rs b/crates/ui-egui/src/dialogs/find_links/tests.rs
new file mode 100644
index 000000000..fe8f38240
--- /dev/null
+++ b/crates/ui-egui/src/dialogs/find_links/tests.rs
@@ -0,0 +1,334 @@
+use std::path::{Path, PathBuf};
+use std::time::Instant;
+
+use vectorcraft_engine::Session;
+use vectorcraft_engine::cmd::findfiles::Rules;
+
+use super::*;
+
+fn frame(app: &mut VectorcraftApp) -> String {
+    crate::tests_labels::painted_text(app, |app, ui| super::super::show(app, ui.ctx()))
+}
+
+/// A fresh temporary folder (canonical, as a search reports it).
+fn folder(tag: &str) -> PathBuf {
+    let dir = vectorcraft_testkit::temp_dir(&format!("find-links-{tag}"));
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).unwrap();
+    vectorcraft_engine::cmd::findfiles::plain(std::fs::canonicalize(&dir).unwrap())
+}
+
+/// An app that reads files, shows a folder picker and whose searches may go anywhere in `root`,
+/// on two threads.
+fn app_for(root: &Path) -> VectorcraftApp {
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.services.read = Some(Box::new(|p: &str| std::fs::read(p).map_err(|e| e.to_string())));
+    app.services.pick_folder = Some(Box::new(|| None));
+    app.session.search_rules = Some(Rules { user_content: vec![root.to_path_buf()], ..Rules::default() });
+    app.session.search_threads = Some(2);
+    app
+}
+
+/// `rel` (`/`-separated) inside `root`, with the platform's separators, as the app reports paths.
+fn at(root: &Path, rel: &str) -> PathBuf {
+    rel.split('/').fold(root.to_path_buf(), |p, c| p.join(c))
+}
+
+fn write(path: &Path, bytes: &[u8]) {
+    std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+    std::fs::write(path, bytes).unwrap();
+}
+
+/// A PNG of one color, a different one for each `n`.
+fn png(n: u8) -> Vec<u8> {
+    let mut out = vec![];
+    image::RgbaImage::from_pixel(40, 30, image::Rgba([200, n.wrapping_mul(40), 0, 255]))
+        .write_to(&mut std::io::Cursor::new(&mut out), image::ImageFormat::Png)
+        .unwrap();
+    out
+}
+
+/// A document linking to files `names` in `root/orig`, saved as `root/doc/doc.vectorcraft`; the
+/// files are then deleted and the document opened again → each file's bytes.
+fn opened_without(app: &mut VectorcraftApp, root: &Path, names: &[&str]) -> Vec<Vec<u8>> {
+    app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
+    let mut files = vec![];
+    for (n, name) in (0..).zip(names) {
+        let path = root.join("orig").join(name);
+        write(&path, &png(n));
+        app.run("file.place", json!({"path": path})).unwrap();
+        files.push(png(n));
+    }
+    let doc = at(root, "doc/doc.vectorcraft");
+    std::fs::create_dir_all(doc.parent().unwrap()).unwrap();
+    app.run("document.save", json!({"path": doc})).unwrap();
+    std::fs::remove_dir_all(root.join("orig")).unwrap();
+    crate::io::open_path(app, &doc.to_string_lossy()).unwrap();
+    files
+}
+
+/// Draw the dialog until its search ends (10 seconds at most).
+fn searched(app: &mut VectorcraftApp) {
+    let until = Instant::now() + Duration::from_secs(10);
+    while app.ui.dialog.as_ref().is_some_and(|d| d.str("state") == "searching") && Instant::now() < until {
+        frame(app);
+        std::thread::sleep(Duration::from_millis(5));
+    }
+}
+
+fn kind(app: &VectorcraftApp) -> Option<&str> {
+    app.ui.dialog.as_ref().map(|d| d.kind.as_str())
+}
+
+/// The pick of the row named `name`.
+fn pick<'a>(d: &'a Dialog, name: &str) -> &'a Value {
+    let i = d.fields["missing"].as_array().unwrap().iter().position(|r| r["name"] == name).unwrap();
+    &d.fields["picks"][i]
+}
+
+/// Find in Folder… in Linked File Not Found: each missing file's same file is chosen, and Relink
+/// relinks them.
+#[test]
+fn find_in_folder_relinks_the_missing_files_to_the_files_found() {
+    let root = folder("relink");
+    let mut app = app_for(&root);
+    let bytes = opened_without(&mut app, &root, &["a.png", "b.png"]);
+    assert_eq!(kind(&app), Some(super::super::missing_links::KIND));
+    assert!(frame(&mut app).contains("Find in Folder…"));
+    let (a, b) = (at(&root, "found/sub/a.png"), at(&root, "found/b.png"));
+    write(&a, &bytes[0]);
+    write(&b, &bytes[1]);
+    write(&at(&root, "found/other/b.png"), b"another file");
+    // What Find in Folder… does with the folder picked.
+    app.ui.dialog.as_mut().unwrap().fields.insert("searchFolder".into(), json!(root.join("found")));
+    let r = super::super::confirm(&mut app).unwrap();
+    assert!(matches!(r["state"].as_str(), Some("searching" | "done")), "{r}");
+    assert_eq!(kind(&app), Some(KIND));
+    searched(&mut app);
+    let d = app.ui.dialog.as_ref().unwrap();
+    assert_eq!((d.str("state"), pick(d, "a.png"), pick(d, "b.png")), ("done".to_string(), &json!(a), &json!(b)));
+    let text = frame(&mut app);
+    for label in
+        ["Find Linked Files", "a.png", "b.png", "Same file", "Don't Relink", "Find in Folder…", "Copy into the document's folder", "Relink"]
+    {
+        assert!(text.contains(label), "{label} in {text}");
+    }
+    super::super::confirm(&mut app).unwrap();
+    assert!(app.ui.dialog.is_none());
+    assert_eq!(app.ui.status, "Relinked 2 image(s)");
+    assert_eq!(app.run("links.check", json!({})).unwrap()["missing"], 0);
+}
+
+/// The files left without a file, or whose file fails to relink, go back to Linked File Not
+/// Found; the failure is named in the status line, and the other files still relink.
+#[test]
+fn files_not_relinked_go_back_to_linked_file_not_found() {
+    let root = folder("back");
+    let mut app = app_for(&root);
+    let bytes = opened_without(&mut app, &root, &["a.png", "b.png", "c.png"]);
+    write(&at(&root, "found/a.png"), &bytes[0]);
+    write(&at(&root, "found/b.png"), b"not an image");
+    app.ui.dialog.as_mut().unwrap().fields.insert("searchFolder".into(), json!(root.join("found")));
+    super::super::confirm(&mut app).unwrap();
+    searched(&mut app);
+    let d = app.ui.dialog.as_ref().unwrap();
+    // b.png's only file is chosen, c.png has none.
+    assert_eq!((pick(d, "b.png"), pick(d, "c.png")), (&json!(at(&root, "found/b.png")), &Value::Null));
+    assert!(frame(&mut app).contains("Not found"));
+    super::super::confirm(&mut app).unwrap();
+    assert!(app.ui.status.starts_with("Relinked 1 image(s); b.png couldn't be relinked: "), "{}", app.ui.status);
+    let d = app.ui.dialog.as_ref().expect("Linked File Not Found again");
+    let names: Vec<&str> = d.fields["missing"].as_array().unwrap().iter().map(|r| r["name"].as_str().unwrap()).collect();
+    assert_eq!((d.kind.as_str(), names.len()), (super::super::missing_links::KIND, 2));
+    assert!(names.contains(&"b.png") && names.contains(&"c.png"), "{names:?}");
+    super::super::cancel(&mut app);
+    assert_eq!(app.run("links.check", json!({})).unwrap()["missing"], 2);
+}
+
+/// A file is chosen when the choice is clear: the only same file, else the only file. A row the
+/// user chose for keeps its choice as the search goes on.
+#[test]
+fn a_file_is_chosen_only_when_the_choice_is_clear() {
+    let row = |p: &str| json!({"name": "a.png", "path": p, "ids": [1]});
+    let mut d = Dialog::new(KIND, json!({"missing": [row("/x/a.png"), row("/y/a.png"), row("/z/a.png")], "picks": [], "touched": []}));
+    let file = |p: &str, m: &str| json!({"path": p, "match": m});
+    let answer = |y: Vec<Value>| {
+        json!({"state": "searching", "links": [
+            {"path": "/x/a.png", "ids": [1], "files": [file("/f/a.png", "same"), file("/g/a.png", "name")]},
+            {"path": "/y/a.png", "ids": [1], "files": y},
+            {"path": "/z/a.png", "ids": [1], "files": [file("/f/a.png", "size"), file("/g/a.png", "name")]},
+        ]})
+    };
+    update(&mut d, &answer(vec![file("/f/a.png", "name")]));
+    assert_eq!(d.fields["picks"], json!(["/f/a.png", "/f/a.png", null]));
+    // Don't Relink chosen for the first row: the next answer leaves it, and the second row has
+    // two files now.
+    d.fields.insert("picks".into(), json!([null, "/f/a.png", null]));
+    d.fields.insert("touched".into(), json!([0]));
+    update(&mut d, &answer(vec![file("/f/a.png", "name"), file("/g/a.png", "name")]));
+    assert_eq!(d.fields["picks"], json!([null, null, null]));
+}
+
+/// A search of another folder starts the choices over: a file chosen from the last folder's
+/// results isn't kept.
+#[test]
+fn another_folder_starts_the_choices_over() {
+    let root = folder("again");
+    let mut app = app_for(&root);
+    opened_without(&mut app, &root, &["a.png"]);
+    super::super::cancel(&mut app);
+    // Two files of the name and neither the same file: the search reads both folders.
+    write(&at(&root, "one/a.png"), b"one file");
+    write(&at(&root, "one/x/a.png"), b"another file");
+    std::fs::create_dir_all(root.join("two")).unwrap();
+    app.run("ui.findLinksInFolder", json!({"folder": root.join("one")})).unwrap();
+    searched(&mut app);
+    assert_eq!(app.ui.dialog.as_ref().unwrap().fields["found"][0]["files"].as_array().map(Vec::len), Some(2));
+    // The second file chosen, then another folder searched, which has no file of the name.
+    let d = app.ui.dialog.as_mut().unwrap();
+    d.fields.insert("picks".into(), json!([at(&root, "one/x/a.png")]));
+    d.fields.insert("touched".into(), json!([0]));
+    d.fields.insert("searchFolder".into(), json!(root.join("two")));
+    super::super::confirm(&mut app).unwrap();
+    searched(&mut app);
+    let d = app.ui.dialog.as_ref().unwrap();
+    assert_eq!((pick(d, "a.png"), &d.fields["touched"]), (&Value::Null, &json!([])));
+}
+
+#[test]
+fn cancel_closes_the_dialog_and_stops_its_search() {
+    let root = folder("cancel");
+    // Enough folders that the search usually still runs when the dialog closes.
+    for a in 0..40 {
+        for b in 0..40 {
+            std::fs::create_dir_all(root.join(format!("tree/f{a}/g{b}"))).unwrap();
+        }
+    }
+    let mut app = app_for(&root);
+    app.session.search_threads = Some(1);
+    opened_without(&mut app, &root, &["a.png"]);
+    super::super::cancel(&mut app);
+    app.run("ui.findLinksInFolder", json!({"folder": root.join("tree")})).unwrap();
+    let id = app.ui.links_search.expect("the dialog's search");
+    assert_eq!((kind(&app), app.ui.dialog.as_ref().unwrap().bool("back")), (Some(KIND), false));
+    super::super::cancel(&mut app);
+    assert!(app.ui.dialog.is_none() && app.ui.links_search.is_none());
+    // Stopped by the close, unless the walker finished the folders first.
+    let r = app.session.execute("links.findFiles", &json!({})).unwrap();
+    assert_eq!(r["id"].as_u64(), Some(id), "{r}");
+    match r["state"].as_str() {
+        Some("stopped") => assert_eq!(r["stopped"], "stop", "{r}"),
+        state => assert_eq!(state, Some("done"), "{r}"),
+    }
+}
+
+/// Copy into the document's folder, for a saved document: the file is copied there first.
+#[test]
+fn copy_into_the_documents_folder_copies_before_relinking() {
+    let root = folder("copy");
+    let mut app = app_for(&root);
+    let bytes = opened_without(&mut app, &root, &["a.png"]);
+    super::super::cancel(&mut app);
+    write(&at(&root, "found/a.png"), &bytes[0]);
+    app.run("ui.findLinksInFolder", json!({"folder": root.join("found")})).unwrap();
+    searched(&mut app);
+    assert!(frame(&mut app).contains("Copy into the document's folder"));
+    app.ui.dialog.as_mut().unwrap().fields.insert("copy".into(), json!(true));
+    let r = super::super::confirm(&mut app).unwrap();
+    assert_eq!((r["relinked"].as_array().unwrap().len(), app.ui.dialog.is_none()), (1, true), "{r}");
+    let copy = at(&root, "doc/a.png");
+    assert_eq!(std::fs::read(&copy).unwrap(), bytes[0]);
+    let c = app.run("links.check", json!({})).unwrap();
+    assert_eq!((c["missing"].as_u64(), c["links"][0]["path"].as_str()), (Some(0), Some(&*copy.to_string_lossy())), "{c}");
+    // An unsaved document has no folder to copy into.
+    app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
+    let id = app.run("file.place", json!({"path": at(&root, "found/a.png")})).unwrap()["ids"][0].clone();
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    app.run("ui.findLinksInFolder", json!({"folder": root.join("found")})).unwrap();
+    searched(&mut app);
+    assert!(!frame(&mut app).contains("Copy into the document's folder"));
+}
+
+/// With Copy into the document's folder, a placed document is relinked where its file is.
+#[test]
+fn copy_leaves_placed_documents_where_they_are() {
+    let root = folder("placed");
+    let mut app = app_for(&root);
+    app.run("file.new", json!({"width": 100, "height": 100})).unwrap();
+    app.run("shape.rectangle", json!({"x": 10, "y": 10, "width": 50, "height": 50})).unwrap();
+    let badge = at(&root, "orig/badge.vectorcraft");
+    std::fs::create_dir_all(badge.parent().unwrap()).unwrap();
+    app.run("document.save", json!({"path": badge})).unwrap();
+    let found = at(&root, "found/badge.vectorcraft");
+    write(&found, &std::fs::read(&badge).unwrap());
+    app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
+    app.run("file.place", json!({"path": badge, "link": true})).unwrap();
+    let doc = at(&root, "doc/doc.vectorcraft");
+    std::fs::create_dir_all(doc.parent().unwrap()).unwrap();
+    app.run("document.save", json!({"path": doc})).unwrap();
+    std::fs::remove_dir_all(root.join("orig")).unwrap();
+    crate::io::open_path(&mut app, &doc.to_string_lossy()).unwrap();
+    super::super::cancel(&mut app);
+    app.run("ui.findLinksInFolder", json!({"folder": root.join("found")})).unwrap();
+    searched(&mut app);
+    app.ui.dialog.as_mut().unwrap().fields.insert("copy".into(), json!(true));
+    let r = super::super::confirm(&mut app).unwrap();
+    assert_eq!((r["relinked"].as_array().unwrap().len(), &r["failed"]), (1, &json!([])), "{r}");
+    assert!(!at(&root, "doc/badge.vectorcraft").exists());
+    assert_eq!(app.run("links.check", json!({})).unwrap()["links"][0]["path"], json!(found));
+}
+
+/// The Links panel's Find in Folder… (`ui.findLinksInFolder`): the selected linked files, else
+/// the missing ones, in a folder the user picks.
+#[test]
+fn the_links_panel_looks_for_the_selected_or_the_missing_files() {
+    let root = folder("panel");
+    let mut app = app_for(&root);
+    app.services.pick_folder = None;
+    app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
+    assert!(!crate::menus::enabled(&app, "ui.findLinksInFolder"), "no folder picker (the web)");
+    let picked = root.join("found").to_string_lossy().into_owned();
+    let answer = picked.clone();
+    app.services.pick_folder = Some(Box::new(move || Some(answer.clone())));
+    assert!(crate::menus::enabled(&app, "ui.findLinksInFolder"));
+    // Nothing to look for: no folder is asked for.
+    assert_eq!(app.run("ui.findLinksInFolder", json!({})).err().as_deref(), Some("No linked files to look for"));
+    let here = at(&root, "found/here.png");
+    write(&here, &png(1));
+    let id = app.run("file.place", json!({"path": here})).unwrap()["ids"][0].clone();
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    let menu = crate::tests_labels::painted_text(&mut app, crate::panels::links::menu);
+    assert!(menu.contains("Find in Folder…"), "{menu}");
+    app.run("ui.findLinksInFolder", json!({})).unwrap();
+    let d = app.ui.dialog.as_ref().unwrap();
+    assert_eq!((d.kind.as_str(), d.fields["missing"][0]["name"].as_str(), d.str("folder")), (KIND, Some("here.png"), picked));
+    // here.png isn't missing: the dialog asks about linked files.
+    assert!(frame(&mut app).contains("Choose the file to relink each linked file to."));
+    searched(&mut app);
+    assert_eq!(pick(app.ui.dialog.as_ref().unwrap(), "here.png"), &json!(here));
+}
+
+/// The Links panel's Find in Folder… asks for the folder off the UI thread (#867): Find Linked
+/// Files opens on the folder when the folder picker answers.
+#[test]
+fn find_in_folder_asks_for_the_folder_off_the_ui_thread() {
+    let root = folder("later");
+    let mut app = app_for(&root);
+    let (shown, _) = crate::tests_picks::off_the_ui_thread(&mut app.services);
+    app.services.read = Some(Box::new(|p: &str| std::fs::read(p).map_err(|e| e.to_string())));
+    app.run("file.new", json!({"width": 400, "height": 300})).unwrap();
+    let here = at(&root, "found/here.png");
+    write(&here, &png(1));
+    let id = app.run("file.place", json!({"path": here})).unwrap()["ids"][0].clone();
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    // Nothing opens until the picker answers.
+    assert!(app.run("ui.findLinksInFolder", json!({})).is_err());
+    assert_eq!((shown.requests(), kind(&app)), (vec![PickRequest::Folder], None));
+    let found = root.join("found").to_string_lossy().into_owned();
+    shown.answer(&[found.as_str()]);
+    crate::picks::poll(&mut app, &egui::Context::default());
+    let d = app.ui.dialog.as_ref().expect("Find Linked Files");
+    assert_eq!((d.kind.as_str(), d.str("folder")), (KIND, found));
+    searched(&mut app);
+    assert_eq!(pick(app.ui.dialog.as_ref().unwrap(), "here.png"), &json!(here));
+}