fix(mdx-loader): avoid transforming dotted directory links into asset…

packages/docusaurus-mdx-loader/src/remark/transformLinks/__tests__/index.test.ts

@@ -80,10 +80,29 @@ describe('transformLinks plugin', () => {
     expect(result).toMatchInlineSnapshot(`"[file](dir/file.zip)"`);
   });
 
+  it('does not transform existing dotted directory links to asset requires', async () => {
+    const result = await processContent(
+      `[directory](../dotted-directory.whatever)`,
+    );
+    expect(result).toMatchInlineSnapshot(
+      `"[directory](../dotted-directory.whatever)"`,
+    );
+  });
+
+  it('does not transform absolute dotted directory links to asset requires', async () => {
+    const result = await processContent(
+      `[directory](/static-dotted-directory.test)`,
+    );
+    expect(result).toMatchInlineSnapshot(
+      `"[directory](/static-dotted-directory.test)"`,
+    );
+  });
+
   describe('onBrokenMarkdownLinks', () => {
     const fixtures = {
       urlEmpty: `[empty]()`,
       fileDoesNotExistSiteAlias: `[file](@site/file.zip)`,
+      directoryWithDotSiteAlias: `[dir](@site/dotted-directory.whatever)`,
     };
 
     describe('throws', () => {
@@ -103,6 +122,15 @@ describe('transformLinks plugin', () => {
           To ignore this error, use the \`siteConfig.markdown.hooks.onBrokenMarkdownLinks\` option, or apply the \`pathname://\` protocol to the broken link URLs."
         `);
       });
+
+      it('if site alias points to a directory with a dot', async () => {
+        await expect(processContent(fixtures.directoryWithDotSiteAlias)).rejects
+          .toThrowErrorMatchingInlineSnapshot(`
+          "Markdown link with URL \`@site/dotted-directory.whatever\` in source file "packages/docusaurus-mdx-loader/src/remark/transformLinks/__tests__/__fixtures__/docs/myFile.mdx" (1:1) couldn't be resolved.
+          Make sure it references a local Markdown file that exists within the current plugin.
+          To ignore this error, use the \`siteConfig.markdown.hooks.onBrokenMarkdownLinks\` option, or apply the \`pathname://\` protocol to the broken link URLs."
+        `);
+      });
     });
 
     describe('warns', () => {
@@ -141,6 +169,22 @@ describe('transformLinks plugin', () => {
           ]
         `);
       });
+
+      it('if site alias points to a directory with a dot', async () => {
+        const result = await processWarn(fixtures.directoryWithDotSiteAlias);
+        expect(result).toMatchInlineSnapshot(
+          `"[dir](@site/dotted-directory.whatever)"`,
+        );
+        expect(warnMock).toHaveBeenCalledTimes(1);
+        expect(warnMock.mock.calls).toMatchInlineSnapshot(`
+          [
+            [
+              "[WARNING] Markdown link with URL \`@site/dotted-directory.whatever\` in source file "packages/docusaurus-mdx-loader/src/remark/transformLinks/__tests__/__fixtures__/docs/myFile.mdx" (1:1) couldn't be resolved.
+          Make sure it references a local Markdown file that exists within the current plugin.",
+            ],
+          ]
+        `);
+      });
     });
 
     describe('function form', () => {
@@ -269,6 +313,60 @@ describe('transformLinks plugin', () => {
           ]
         `);
       });
+
+      it('if site alias points to a directory with a dot', async () => {
+        const result = await processWarn(fixtures.directoryWithDotSiteAlias);
+        expect(result).toMatchInlineSnapshot(
+          `"[dir](/404 "fixed link title")"`,
+        );
+        expect(logMock).toHaveBeenCalledTimes(1);
+        expect(logMock.mock.calls).toMatchInlineSnapshot(`
+          [
+            [
+              "onBrokenMarkdownLinks called with",
+              {
+                "node": {
+                  "children": [
+                    {
+                      "position": {
+                        "end": {
+                          "column": 5,
+                          "line": 1,
+                          "offset": 4,
+                        },
+                        "start": {
+                          "column": 2,
+                          "line": 1,
+                          "offset": 1,
+                        },
+                      },
+                      "type": "text",
+                      "value": "dir",
+                    },
+                  ],
+                  "position": {
+                    "end": {
+                      "column": 39,
+                      "line": 1,
+                      "offset": 38,
+                    },
+                    "start": {
+                      "column": 1,
+                      "line": 1,
+                      "offset": 0,
+                    },
+                  },
+                  "title": "fixed link title",
+                  "type": "link",
+                  "url": "/404",
+                },
+                "sourceFilePath": "packages/docusaurus-mdx-loader/src/remark/transformLinks/__tests__/__fixtures__/docs/myFile.mdx",
+                "url": "@site/dotted-directory.whatever",
+              },
+            ],
+          ]
+        `);
+      });
     });
   });
 });

packages/docusaurus-mdx-loader/src/remark/transformLinks/index.ts

@@ -171,26 +171,38 @@ async function toAssetRequireNode(
   });
 }
 
+/**
+ * Checks if the given file path exists and is a file.
+ * Returns true if it exists, false otherwise.
+ */
+async function isExistingFile(filePath: string): Promise<boolean> {
+  try {
+    return (await fs.stat(filePath)).isFile();
+  } catch {
+    return false;
+  }
+}
+
 async function getLocalFileAbsolutePath(
   assetPath: string,
   {siteDir, filePath, staticDirs}: Context,
 ) {
   if (assetPath.startsWith('@site/')) {
     const assetFilePath = path.join(siteDir, assetPath.replace('@site/', ''));
-    if (await fs.pathExists(assetFilePath)) {
+    if (await isExistingFile(assetFilePath)) {
       return assetFilePath;
     }
   } else if (path.isAbsolute(assetPath)) {
     const assetFilePath = await findAsyncSequential(
       staticDirs.map((dir) => path.join(dir, assetPath)),
-      fs.pathExists,
+      isExistingFile,
     );
     if (assetFilePath) {
       return assetFilePath;
     }
   } else {
     const assetFilePath = path.join(path.dirname(filePath), assetPath);
-    if (await fs.pathExists(assetFilePath)) {
+    if (await isExistingFile(assetFilePath)) {
       return assetFilePath;
     }
   }