fix(links): Fix relative link resolution (#30)

spec/link_utils_spec.js

@@ -29,7 +29,41 @@ describe('linkUtils.getAbsolute', () => {
   });
 });
 
-xdescribe('linkUtils.resolveLinks', () => {
+describe('linkUtils.getRelative', () => {
+  const files = [
+    {
+      actualUrl: 'https://www.github.com/user/repo/blob/master/docs/doc.md',
+      name: 'doc.md',
+      path: 'docs/doc.md',
+      relativePath: './doc.md',
+      repo: 'repo'
+    },
+    {
+      actualUrl: 'https://www.github.com/user/repo/blob/master/docs/subdir/doc.md',
+      name: 'doc.md',
+      path: 'docs/subdir/doc.md',
+      relativePath: './subdir/doc.md',
+      repo: 'repo'
+    },
+    {
+      actualUrl: 'https://www.github.com/user/repo2/blob/master/docs/sub/doc.md',
+      name: 'doc.md',
+      path: 'docs/sub/doc.md',
+      relativePath: './sub/docs.md',
+      repo: 'repo2'
+    }
+  ];
+
+  it('returns a relative path from one absolute location to another within the same repo', () => {
+    expect(linkUtils.getRelative(files[1], files[0])).toEqual('../doc.md');
+  });
+
+  it('returns a relative path from one absolute location to another within another known repo', () => {
+    expect(linkUtils.getRelative(files[2], files[0])).toEqual('../../repo/doc.md');
+  });
+});
+
+describe('linkUtils.resolveLinks', () => {
   describe('given markdown content', () => {
     const unkownRelativeMarkdown = `
       # headline
@@ -56,15 +90,32 @@ xdescribe('linkUtils.resolveLinks', () => {
     const knownLocations = [
       {
         actualUrl: 'https://www.github.com/user/repo/blob/master/docs/doc.md',
-        path: 'docs/doc.md'
+        name: 'doc.md',
+        path: 'docs/doc.md',
+        relativePath: './doc.md',
+        repo: 'repo'
+      },
+      {
+        actualUrl: 'https://www.github.com/user/repo/blob/master/docs/doc.md',
+        name: 'docs/doc.md',
+        path: 'docs/doc.md',
+        relativePath: './doc.md',
+        repo: 'repo'
+      },
+      {
+        actualUrl: 'https://www.github.com/user/repo2/blob/master/docs/sub/doc.md',
+        name: 'doc.md',
+        path: 'docs/sub/doc.md',
+        relativePath: './sub/docs.md',
+        repo: 'repo2'
       }
     ];
 
     it('updates unknown relative links to be exact', () => {
       const output = linkUtils.resolveLinks(
         unkownRelativeMarkdown,
         knownLocations,
-        'https://www.github.com/user/repo/blob/master/docs/'
+        knownLocations[0]
       );
       expect(output).toContain(
         'Some content with an unknown [link](https://www.github.com/user/repo/blob/master/images/thing.png)'
@@ -75,7 +126,7 @@ xdescribe('linkUtils.resolveLinks', () => {
       const output = linkUtils.resolveLinks(
         knownRelativeMarkdown,
         knownLocations,
-        'https://www.github.com/user/repo/blob/master/'
+        knownLocations[1]
       );
       expect(output).toContain('Some content with a known [link](./doc.md)');
     });
@@ -84,26 +135,24 @@ xdescribe('linkUtils.resolveLinks', () => {
       const output = linkUtils.resolveLinks(
         knownRelativeMarkdownInCurrentDir,
         knownLocations,
-        'https://www.github.com/user/repo/blob/master/docs/'
+        knownLocations[0]
       );
       expect(output).toContain('a known [link](./doc.md)');
     });
 
-    it('updates known exact links to be relative', () => {
-      const output = linkUtils.resolveLinks(
-        absoluteMarkdown,
-        knownLocations,
-        'https://www.github.com/user/repo/blob/master/docs/'
-      );
+    it('updates known exact links to be relative within the same repo', () => {
+      const output = linkUtils.resolveLinks(absoluteMarkdown, knownLocations, knownLocations[0]);
       expect(output).toContain('a [known doc](./doc.md)');
     });
 
+    it('updates known exact links to be relative from another repo', () => {
+      // Go back out to root, then back in on another project
+      const output = linkUtils.resolveLinks(absoluteMarkdown, knownLocations, knownLocations[2]);
+      expect(output).toContain('a [known doc](../../repo/doc.md)');
+    });
+
     it('does not update local header references', () => {
-      const output = linkUtils.resolveLinks(
-        localMarkdown,
-        knownLocations,
-        'https://www.github.com/user/repo/blob/master/docs/'
-      );
+      const output = linkUtils.resolveLinks(localMarkdown, knownLocations, knownLocations[0]);
       expect(output).toEqual(localMarkdown);
     });
   });

src/link_utils.js

@@ -30,7 +30,29 @@ const getAbsolute = (baseUrl, path) => {
   return stack.join('/');
 };
 
-const resolveLinks = (markdownContent, knownFiles, absoluteLocation) => {
+const getRelative = (fromLink, toLink) => {
+  let fromLinkRelative = '';
+  const removeFirstTwoChars = toLink.relativePath.slice(0, 2) === './';
+  let toLinkRelative = removeFirstTwoChars
+    ? toLink.relativePath.slice(2, toLink.relativePath.length)
+    : toLink.relativePath;
+
+  const fromDirCount = fromLink.relativePath.split('/').length - 2;
+
+  for (let index = 0; index < fromDirCount; index++) {
+    fromLinkRelative += '../';
+  }
+
+  if (fromLink.repo !== toLink.repo) {
+    toLinkRelative = `../${toLink.repo}/${toLinkRelative}`;
+  }
+
+  const result = (fromLinkRelative || './') + toLinkRelative;
+
+  return result;
+};
+
+const resolveLinks = (markdownContent, knownFiles, currentFile) => {
   const markdownLinkMatcher = /\[([^[\]]+)\]\(([^)]+)/gm;
   let markdownContentCopy = markdownContent;
   let match;
@@ -39,11 +61,15 @@ const resolveLinks = (markdownContent, knownFiles, absoluteLocation) => {
     const linkIsLocalHeader = match[2][0] === '#';
     if (linkIsLocalHeader) return markdownContentCopy;
 
-    const absoluteUrl = getAbsolute(absoluteLocation, match[2]);
+    const absLocation = currentFile.actualUrl.replace(currentFile.name, '');
+    const absoluteUrl = getAbsolute(absLocation, match[2]);
     const knownFile = knownFiles.find(fileData => fileData.actualUrl === absoluteUrl);
 
     if (knownFile) {
-      markdownContentCopy = markdownContentCopy.replace(match[2], `${knownFile.relativePath}`);
+      markdownContentCopy = markdownContentCopy.replace(
+        match[2],
+        getRelative(currentFile, knownFile)
+      );
     } else {
       markdownContentCopy = markdownContentCopy.replace(match[2], absoluteUrl);
     }
@@ -54,5 +80,6 @@ const resolveLinks = (markdownContent, knownFiles, absoluteLocation) => {
 
 module.exports = {
   getAbsolute,
+  getRelative,
   resolveLinks
 };

src/resolve_links.js

@@ -20,8 +20,7 @@ const resolveLinks = fileList => {
           return reject(readError);
         }
 
-        const absLocation = file.actualUrl.replace(file.name, '');
-        const resolvedData = linkUtils.resolveLinks(data, fileList, absLocation);
+        const resolvedData = linkUtils.resolveLinks(data, fileList, file);
 
         fs.writeFile(fileUtils.findLocalFilePath(file), resolvedData, writeError => {
           if (writeError) {