[BUG] fails to parse commits with nested parentheses

[jguddas]

Description

Conventional commit parsing in release-please can misbehave or fail when a commit or it's body contains nested parentheses, such as code references or function calls (e.g., Foo.Bar(baz(abc))). This issue is particularly notable in GitHub squash merge commits where nested parentheses are nested inside squashed comments or split commits in the message body.

Test Cases

Here are the test cases that demonstrate the desired behavior:

  it('handles commits with nested parentheses in body', async () => {
    const commits = [
      buildMockCommit(
        'feat: something\n\nFoo.Bar(baz(abc)). Some trailing text.'
      ),
    ];
    const conventionalCommits = parseConventionalCommits(commits);
    expect(conventionalCommits).lengthOf(1);
    expect(conventionalCommits[0].type).to.equal('feat');
  });

  it('handles a GitHub squash merge commit with nested parentheses inside squashed comments in the body', async () => {
    const squashCommitMessage = 
      'feat(scope): some message (#123)\n\n' +
      '* refactor(subscope): first squashed change\n\n' +
      'Some details here.\n\n' +
      '* refactor(subscope): second squashed change\n\n' +
      'Foo.Bar(baz(abc)). More details.';

    const commits = [buildMockCommit(squashCommitMessage)];
    const conventionalCommits = parseConventionalCommits(commits);
    expect(conventionalCommits).lengthOf(1);
    expect(conventionalCommits[0].type).to.equal('feat');
    expect(conventionalCommits[0].scope).to.equal('scope');
  });

  it('handles a squash merge with split commits that contain a nested parenthesis commit', async () => {
    const squashSplitMessage = 
      'feat(scope): some message (#123)\n\n' +
      'refactor(subscope): first squashed change\n\n' +
      'Some details here.\n\n' +
      'refactor(subscope): second squashed change\n\n' +
      'Foo.Bar(baz(abc)). More details.';

    const commits = [buildMockCommit(squashSplitMessage)];
    const conventionalCommits = parseConventionalCommits(commits);
    expect(conventionalCommits).lengthOf(3);
    expect(conventionalCommits[0].type).to.equal('feat');
    expect(conventionalCommits[1].type).to.equal('refactor');
    expect(conventionalCommits[2].type).to.equal('refactor');
  });