feat: allow nesting multiple commits that are parsed independently (g…

…oogleapis#1566)

* test: failing test for parsing commit with special commit separator annotations

* feat: allow nesting multiple commits that are parsed independently

src/commit.ts

@@ -338,6 +338,23 @@ function parseCommits(message: string): parser.ConventionalChangelogCommit[] {
   ).map(postProcessCommits);
 }
 
+// If someone wishes to aggregate multiple, complex commit messages into a
+// single commit, they can include one or more `BEGIN_NESTED_COMMIT`/`END_NESTED_COMMIT`
+// blocks into the body of the commit
+function splitMessages(message: string): string[] {
+  const parts = message.split('BEGIN_NESTED_COMMIT');
+  const messages = [parts.shift()!];
+  for (const part of parts) {
+    const [newMessage, ...rest] = part.split('END_NESTED_COMMIT');
+    messages.push(newMessage);
+    // anthing outside of the BEGIN/END annotations are added to the original
+    // commit
+    messages[0] = messages[0] + rest.join();
+  }
+
+  return messages;
+}
+
 /**
  * Given a list of raw commits, parse and expand into conventional commits.
  *
@@ -354,31 +371,34 @@ export function parseConventionalCommits(
   const conventionalCommits: ConventionalCommit[] = [];
 
   for (const commit of commits) {
-    const commitMessage = preprocessCommitMessage(commit);
-    try {
-      for (const parsedCommit of parseCommits(commitMessage)) {
-        const breaking =
-          parsedCommit.notes.filter(note => note.title === 'BREAKING CHANGE')
-            .length > 0;
-        conventionalCommits.push({
-          sha: commit.sha,
-          message: parsedCommit.header,
-          files: commit.files,
-          pullRequest: commit.pullRequest,
-          type: parsedCommit.type,
-          scope: parsedCommit.scope,
-          bareMessage: parsedCommit.subject,
-          notes: parsedCommit.notes,
-          references: parsedCommit.references,
-          breaking,
-        });
+    for (const commitMessage of splitMessages(
+      preprocessCommitMessage(commit)
+    )) {
+      try {
+        for (const parsedCommit of parseCommits(commitMessage)) {
+          const breaking =
+            parsedCommit.notes.filter(note => note.title === 'BREAKING CHANGE')
+              .length > 0;
+          conventionalCommits.push({
+            sha: commit.sha,
+            message: parsedCommit.header,
+            files: commit.files,
+            pullRequest: commit.pullRequest,
+            type: parsedCommit.type,
+            scope: parsedCommit.scope,
+            bareMessage: parsedCommit.subject,
+            notes: parsedCommit.notes,
+            references: parsedCommit.references,
+            breaking,
+          });
+        }
+      } catch (_err) {
+        logger.debug(
+          `commit could not be parsed: ${commit.sha} ${
+            commit.message.split('\n')[0]
+          }`
+        );
       }
-    } catch (_err) {
-      logger.debug(
-        `commit could not be parsed: ${commit.sha} ${
-          commit.message.split('\n')[0]
-        }`
-      );
     }
   }
 

test/commits.ts

@@ -15,7 +15,7 @@
 import {describe, it} from 'mocha';
 
 import {expect} from 'chai';
-import {parseConventionalCommits} from '../src/commit';
+import {parseConventionalCommits, ConventionalCommit} from '../src/commit';
 import {buildCommitFromFixture, buildMockCommit} from './helpers';
 
 describe('parseConventionalCommits', () => {
@@ -194,6 +194,7 @@ describe('parseConventionalCommits', () => {
     expect(conventionalCommits[0].type).to.eql('fix');
     expect(conventionalCommits[0].bareMessage).to.eql('some fix');
   });
+
   it('can override the commit message from BEGIN_COMMIT_OVERRIDE body with a meta commit', async () => {
     const commit = buildMockCommit('chore: some commit');
     const body =
@@ -216,6 +217,32 @@ describe('parseConventionalCommits', () => {
     expect(conventionalCommits[1].bareMessage).to.eql('some fix');
   });
 
+  it('handles a special commit separator', async () => {
+    const commits = [buildCommitFromFixture('multiple-commits-with-separator')];
+    const conventionalCommits = parseConventionalCommits(commits);
+    let commit = assertHasCommit(
+      conventionalCommits,
+      'annotating some fields as REQUIRED'
+    );
+    expect(commit.type).to.eql('fix');
+    commit = assertHasCommit(
+      conventionalCommits,
+      'include metadata file, add exclusions for samples to handwritten libraries'
+    );
+    expect(commit.type).to.eql('docs');
+    expect(commit.scope).to.eql('samples');
+    commit = assertHasCommit(
+      conventionalCommits,
+      'add flag to distinguish autogenerated libs with a handwritten layer'
+    );
+    expect(commit.type).to.eql('build');
+    commit = assertHasCommit(
+      conventionalCommits,
+      'update v2.14.1 gapic-generator-typescript'
+    );
+    expect(commit.type).to.eql('chore');
+  });
+
   // it('ignores reverted commits', async () => {
   //   const commits = [
   //     {sha: 'sha1', message: 'feat: some feature', files: ['path1/file1.txt']},
@@ -236,3 +263,14 @@ describe('parseConventionalCommits', () => {
   //   expect(conventionalCommits[0].scope).is.null;
   // });
 });
+
+function assertHasCommit(
+  commits: ConventionalCommit[],
+  bareMessage: string
+): ConventionalCommit {
+  const found = commits.find(commit =>
+    commit.bareMessage.includes(bareMessage)
+  );
+  expect(found, `commit with message: '${bareMessage}'`).to.not.be.undefined;
+  return found!;
+}

test/fixtures/commit-messages/multiple-commits-with-separator.txt

@@ -0,0 +1,35 @@
+fix: annotating some fields as REQUIRED
+
+These fields were actually always required by the backend, so annotation just documents status quo. I believe this change will not require major version bump for any language.
+
+PiperOrigin-RevId: 429093810
+Source-Link: googleapis/googleapis@dc04c1c
+Source-Link: https://github.com/googleapis/googleapis-gen/commit/0e23469bea2f397f2b783c5a25e64452f86be6bc
+Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiMGUyMzQ2OWJlYTJmMzk3ZjJiNzgzYzVhMjVlNjQ0NTJmODZiZTZiYyJ9
+See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md
+BEGIN_NESTED_COMMIT
+docs(samples): include metadata file, add exclusions for samples to handwritten libraries
+PiperOrigin-RevId: 429395631
+Source-Link: googleapis/googleapis@84594b3
+Source-Link: https://github.com/googleapis/googleapis-gen/commit/ed74f970fd82914874e6b27b04763cfa66bafe9b
+Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiZWQ3NGY5NzBmZDgyOTE0ODc0ZTZiMjdiMDQ3NjNjZmE2NmJhZmU5YiJ9
+See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md
+END_NESTED_COMMIT
+BEGIN_NESTED_COMMIT
+build: add flag to distinguish autogenerated libs with a handwritten layer
+PiperOrigin-RevId: 430741048
+Source-Link: googleapis/googleapis@6bd2087
+Source-Link: https://github.com/googleapis/googleapis-gen/commit/3691f4b4f9e4ba024ab044b946fc8572129e8c06
+Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiMzY5MWY0YjRmOWU0YmEwMjRhYjA0NGI5NDZmYzg1NzIxMjllOGMwNiJ9
+END_NESTED_COMMIT
+BEGIN_NESTED_COMMIT
+chore: update v2.14.1 gapic-generator-typescript
+Committer: @summer-ji-eng
+PiperOrigin-RevId: 433031262
+Source-Link: googleapis/googleapis@2a55d13
+Source-Link: https://github.com/googleapis/googleapis-gen/commit/2fce3893ae9da47763e0872c4a3a87d9ff78771f
+Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiMmZjZTM4OTNhZTlkYTQ3NzYzZTA4NzJjNGEzYTg3ZDlmZjc4NzcxZiJ9
+See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md
+END_NESTED_COMMIT
+Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
+Co-authored-by: Benjamin E. Coe <[email protected]>