fix(path): resolve short wikilinks to folder notes

.changeset/folder-note-shortest-links.md

@@ -0,0 +1,9 @@
+---
+"@quartz-community/utils": patch
+---
+
+Resolve short wikilinks to Obsidian folder notes.
+
+`slugifyFilePath` rewrites `Foo/Foo.md` to the slug `Foo/index`. The last path segment is then `index`, so the `shortest` strategy in `transformLink` never matched a short `[[Foo]]` link. The link resolved to a root-relative "guess" that does not exist, and no error occurred.
+
+`transformLink` now retries against the folder name. The retry runs only when no real file claims that name. Links that already resolve do not change.

src/path.ts

@@ -258,7 +258,7 @@ export function transformLink(src: FullSlug, target: string, opts: TransformOpti
     if (opts.strategy === "shortest") {
       const isMultiSegment = targetCanonical.includes("/");
       const isFolderTarget = isFolderPath(targetSlug);
-      const matchingFileNames = opts.allSlugs.filter((slug) => {
+      let matchingFileNames = opts.allSlugs.filter((slug) => {
         if (isMultiSegment) {
           // Multi-segment partial path: match by suffix
           if (slug === targetCanonical || slug.endsWith("/" + targetCanonical)) {
@@ -276,6 +276,15 @@ export function transformLink(src: FullSlug, target: string, opts: TransformOpti
         return targetCanonical === fileName;
       });
 
+      // Folder note Foo/Foo.md slugs to Foo/index, so its last segment never matches [[Foo]]
+      // Retry by folder name, only when no real file claims it
+      if (matchingFileNames.length === 0 && !isMultiSegment) {
+        matchingFileNames = opts.allSlugs.filter((slug) => {
+          const parts = slug.split("/");
+          return parts.at(-1) === "index" && parts.at(-2) === targetCanonical;
+        });
+      }
+
       if (matchingFileNames.length === 1) {
         const matchedSlug = matchingFileNames[0]!;
         return (resolveRelative(effectiveSrc, matchedSlug) + targetAnchor) as RelativeURL;

test/path.test.ts

@@ -442,6 +442,22 @@ describe("transformLink", () => {
       expect(transformLink(cur, "index", opts)).toBe("../../");
     });
 
+    it("resolves a folder note by its folder name", () => {
+      // slugifyFilePath gives a/b/b.md the slug a/b/index, per Obsidian folder-note convention
+      const cur = "a/b/c" as FullSlug;
+      expect(transformLink(cur, "b", opts)).toBe("../../a/b/");
+    });
+
+    it("prefers a real file over a folder note of the same name", () => {
+      const withCollision = [...allSlugs, "archive/b"] as FullSlug[];
+      const collisionOpts: TransformOptions = {
+        strategy: "shortest",
+        allSlugs: withCollision,
+      };
+      const cur = "a/b/c" as FullSlug;
+      expect(transformLink(cur, "b", collisionOpts)).toBe("../../archive/b");
+    });
+
     it("resolves from a/b/index (explicit index slug)", () => {
       const cur = "a/b/index" as FullSlug;
       expect(transformLink(cur, "d", opts)).toBe("../../a/b/d");