fix: allow category extraction when scope is used (#240)

This PR changes the category extraction to use a RegExp to matches
[**Conventional Commits** that start with `feat:` or `fix:` (optionally
with a scope like
`feat(scope):`)](https://www.conventionalcommits.org/en/v1.0.0/#:~:text=A%20scope%20may%20be%20provided%20to%20a%20commit%E2%80%99s%20type%2C%20to%20provide%20additional%20contextual%20information%20and%20is%20contained%20within%20parenthesis%2C%20e.g.%2C%20feat(parser)%3A%20add%20ability%20to%20parse%20arrays.).

- adds tests for getCategory to make sure all previous behaviours are
preserved and new one works.
- exports getCategory to make it testable.
- updates getCategory to use regex to extract known category even when
scope is present.

### Regex breakdown

- `^` – Start of the string
- `(feat|fix)` – Must start with either `feat` or `fix`
- `(?:\([^)]*\))?` – Optionally match a scope in parentheses like
`(bridge)` or `(ramps)`
- `\s*:\s*` – Requires a colon `:` (with optional spaces before/after)
- `/u` – Unicode flag (as GitHub allows PR titles to contain unicode)

See https://consensys.slack.com/archives/C08N7NQRBPU/p1745578034343929

---------

Co-authored-by: Jongsun Suh <[email protected]>

Author: NicolasMassart

src/update-changelog.test.ts

@@ -1,5 +1,7 @@
+import { ChangeCategory } from './constants';
 import * as ChangeLogUtils from './get-new-changes';
 import * as ChangeLogManager from './update-changelog';
+import { getCategory } from './update-changelog';
 
 const emptyChangelog = `# Changelog
 All notable changes to this project will be documented in this file.
@@ -59,3 +61,47 @@ describe('updateChangelog', () => {
     expect(result).not.toContain('### Added');
   });
 });
+
+describe('getCategory', () => {
+  it('categorizes feat: prefix as Added', () => {
+    const description = 'feat: add new feature';
+    expect(getCategory(description)).toBe(ChangeCategory.Added);
+  });
+
+  it('categorizes fix: prefix as Fixed', () => {
+    const description = 'fix: resolve bug issue';
+    expect(getCategory(description)).toBe(ChangeCategory.Fixed);
+  });
+
+  it('finds category even if title has spaces', () => {
+    const description = 'feat : add new feature';
+    expect(getCategory(description)).toBe(ChangeCategory.Added);
+  });
+
+  it('returns Uncategorized for unknown prefix', () => {
+    const description = 'foo: update documentation';
+    expect(getCategory(description)).toBe(ChangeCategory.Uncategorized);
+  });
+
+  it('returns Uncategorized for title without colon', () => {
+    const description = 'just a regular commit message';
+    expect(getCategory(description)).toBe(ChangeCategory.Uncategorized);
+  });
+
+  it('returns Uncategorized for empty title', () => {
+    const description = '';
+    expect(getCategory(description)).toBe(ChangeCategory.Uncategorized);
+  });
+
+  it('returns category in title with multiple colons', () => {
+    const description = 'feat: add new feature: with details';
+    expect(getCategory(description)).toBe(ChangeCategory.Added);
+  });
+
+  // according to Conventional Commit practice, category can be followed by a scope
+  // see https://www.conventionalcommits.org/en/v1.0.0/
+  it('returns category with category scope', () => {
+    const description = 'feat(bridge): add new feature for the bridge scope';
+    expect(getCategory(description)).toBe(ChangeCategory.Added);
+  });
+});

src/update-changelog.ts

@@ -213,10 +213,12 @@ async function runCommand(command: string, args: string[]): Promise<string[]> {
  * @param description - The commit message description.
  * @returns The category of the change.
  */
-function getCategory(description: string): ChangeCategory {
-  // Check if description contains a colon
-  if (description.includes(':')) {
-    const [prefix] = description.split(':').map((part) => part.trim());
+export function getCategory(description: string): ChangeCategory {
+  const conventionalCommitPattern = /^(feat|fix)(?:\([^)]+\))?\s*:\s*/u;
+  const match = description.match(conventionalCommitPattern);
+
+  if (match) {
+    const prefix = match.length > 1 ? match[1] : undefined;
     switch (prefix) {
       case ConventionalCommitType.Feat:
         return ChangeCategory.Added;