feat: autodetect changelog file name (#1770)

Improves changelog detection algorithm to look for different upper/lower case options as well as alternative filenames like `History.md`.

Resolves #1754

lib/workers/pr/release-notes.js

 const ghGot = require('../../platform/github/gh-got-wrapper');
+const changelogFilenameRegex = require('changelog-filename-regex');
 const MarkdownIt = require('markdown-it');
 
 const markdown = new MarkdownIt('zero');
@@ -101,20 +102,30 @@ function sectionize(text, level) {
 
 async function getReleaseNotesMd(repository, version) {
   logger.debug(`getReleaseNotes(${repository}, ${version})`);
-  let changelogMd;
+  let changelogMd = '';
   try {
-    const res = await ghGot(
-      `https://api.github.com/repos/${repository}/contents/CHANGELOG.md`
-    );
+    const apiPrefix = `https://api.github.com/repos/${repository}/contents/`;
+    const filesRes = await ghGot(apiPrefix);
+    const files = filesRes.body
+      .map(f => f.name)
+      .filter(f => changelogFilenameRegex.test(f));
+    if (!files.length) {
+      logger.debug('no changelog file found');
+      return null;
+    }
+    const file = files[0];
+    /* istanbul ignore if */
+    if (files.length > 1) {
+      logger.info(`Multiple candidates for changelog file, using ${file}`);
+    }
+    const fileRes = await ghGot(`${apiPrefix}/${file}`);
     changelogMd =
-      Buffer.from(res.body.content, 'base64').toString() + '\n#\n##';
+      Buffer.from(fileRes.body.content, 'base64').toString() + '\n#\n##';
   } catch (err) {
-    // Probably a 404
-  }
-  if (!changelogMd) {
-    logger.debug('CHANGELOG.md not found');
+    // Probably a 404?
     return null;
   }
+
   changelogMd = changelogMd.replace(/\n\s*<a name="[^"]*">.*?<\/a>\n/g, '\n');
   for (const level of [1, 2, 3, 4, 5, 6, 7]) {
     const changelogParsed = sectionize(changelogMd, level);

package.json

@@ -53,6 +53,7 @@
     "cacache": "10.0.4",
     "chalk": "2.3.2",
     "changelog": "1.4.2",
+    "changelog-filename-regex": "1.1.1",
     "child-process-promise": "2.2.1",
     "clean-git-ref": "1.0.3",
     "commander": "2.15.1",

test/workers/pr/release-notes.spec.js

@@ -19,6 +19,12 @@ const jsYamlChangelogMd = fs.readFileSync(
   'utf8'
 );
 
+const contentsResponse = [
+  { name: 'lib' },
+  { name: 'CHANGELOG.md' },
+  { name: 'README.md' },
+];
+
 jest.mock('gh-got');
 
 describe('workers/pr/release-notes', () => {
@@ -36,8 +42,17 @@ describe('workers/pr/release-notes', () => {
       const res = await getReleaseNotesMd('chalk', '2.0.0');
       expect(res).toBe(null);
     });
-    it('handles wrong format', async () => {
+    it('handles files mismatch', async () => {
       ghGot.mockReturnValueOnce({
+        body: [{ name: 'lib' }, { name: 'README.md' }],
+      });
+      const res = await getReleaseNotesMd('chalk', '2.0.0');
+      expect(res).toBe(null);
+    });
+    it('handles wrong format', async () => {
+      ghGot
+        .mockReturnValueOnce({ body: contentsResponse })
+        .mockReturnValueOnce({
           body: {
             content: Buffer.from('not really markdown').toString('base64'),
           },
@@ -46,7 +61,9 @@ describe('workers/pr/release-notes', () => {
       expect(res).toBe(null);
     });
     it('handles bad markdown', async () => {
-      ghGot.mockReturnValueOnce({
+      ghGot
+        .mockReturnValueOnce({ body: contentsResponse })
+        .mockReturnValueOnce({
           body: {
             content: Buffer.from(`#\nha\nha\n#\nha\nha`).toString('base64'),
           },
@@ -55,7 +72,9 @@ describe('workers/pr/release-notes', () => {
       expect(res).toBe(null);
     });
     it('parses angular.js', async () => {
-      ghGot.mockReturnValueOnce({
+      ghGot
+        .mockReturnValueOnce({ body: contentsResponse })
+        .mockReturnValueOnce({
           body: {
             content: Buffer.from(angularJsChangelogMd).toString('base64'),
           },
@@ -65,7 +84,9 @@ describe('workers/pr/release-notes', () => {
       expect(res).toMatchSnapshot();
     });
     it('parses jest', async () => {
-      ghGot.mockReturnValueOnce({
+      ghGot
+        .mockReturnValueOnce({ body: contentsResponse })
+        .mockReturnValueOnce({
           body: {
             content: Buffer.from(jestChangelogMd).toString('base64'),
           },
@@ -75,7 +96,9 @@ describe('workers/pr/release-notes', () => {
       expect(res).toMatchSnapshot();
     });
     it('parses js-yaml', async () => {
-      ghGot.mockReturnValueOnce({
+      ghGot
+        .mockReturnValueOnce({ body: contentsResponse })
+        .mockReturnValueOnce({
           body: {
             content: Buffer.from(jsYamlChangelogMd).toString('base64'),
           },

yarn.lock

@@ -895,6 +895,10 @@ chalk@^1.1.3:
     strip-ansi "^3.0.0"
     supports-color "^2.0.0"
 
+changelog-filename-regex@1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/changelog-filename-regex/-/changelog-filename-regex-1.1.1.tgz#8a2eb3049a652e3c03c8b601e3cbb032ee9f4e6d"
+
 changelog@1.4.2:
   version "1.4.2"
   resolved "https://registry.yarnpkg.com/changelog/-/changelog-1.4.2.tgz#618abaecfaff42cf2452d52c195ff83b5589d2fe"