feat: support BREAKING CHANGE

README.md

@@ -59,8 +59,9 @@ This is a release commit. Returning false.
 Based on a commit's conventional commit message type:
 
 1. If the type is `feat` `fix`, or `perf`, it's considered "meaningful"
-2. If the type is `docs`, `refactor`, `style`, or `test`, it's ignored
-3. If the message looks like `v1.2.3`, `chore: release 1.2.3`, or similar, it's considered a "release"
+1. If the commit is marked as being a breaking change, either via a `BREAKING CHANGE:` at the start of any commit message lines or via an `!` appended to the type, it's considered "meaningful"
+1. If the type is `docs`, `refactor`, `style`, or `test`, it's ignored
+1. If the message looks like `v1.2.3`, `chore: release 1.2.3`, or similar, it's considered a "release"
 
 See [`getCommitMeaning`](./src/getCommitMeaning.ts) for the exact logic used.
 

src/getCommitMeaning.test.ts

@@ -40,6 +40,41 @@ describe("getCommitMeaning", () => {
 		["chore(deps): release", "release"],
 		["chore(deps): release 1.2.3", "release"],
 		["chore(deps): release v1.2.3", "release"],
+		["chore!: message", "meaningful"],
+		["docs!: message", "meaningful"],
+		["chore!: release", "meaningful"],
+		["feat!: a feature with a breaking change", "meaningful"],
+		["chore: bump\n\nBREAKING CHANGE: breaks things", "meaningful"],
+		["chore: bump\n\nBREAKING-CHANGE: breaks things", "meaningful"],
+		["docs: bump\n\nBREAKING CHANGE: breaks things", "meaningful"],
+		["docs: bump\n\nBREAKING-CHANGE: breaks things", "meaningful"],
+		[
+			"chore: deps\n\nBREAKING-CHANGE: breaks things\nMultiple: footer notes",
+			"meaningful",
+		],
+		["chore: deps\n\n! in the commit body", { type: "chore" }],
+		[
+			"chore: deps\n\nFooter-note: other than BREAKING CHANGE",
+			{ type: "chore" },
+		],
+		[
+			"chore: deps\n\nMultiple: footer notes\nMultiple: footer notes",
+			{ type: "chore" },
+		],
+		// This test may should be { type: "chore" },
+		// but conventionalCommitsParser looks like can't parse this case correctly
+		[
+			"chore: deps\n\nBREAKING CHANGE line starts with BREAKING CHANGE (no :)",
+			"meaningful",
+		],
+		[
+			"chore: deps\n\nline contains BREAKING CHANGE:  inside it",
+			{ type: "chore" },
+		],
+		[
+			"BREAKING CHANGE (major): line starts with something like BREAKING CHANGE",
+			{ type: undefined },
+		],
 	])("returns %j for %s", (input, expected) => {
 		expect(getCommitMeaning(input)).toEqual(expected);
 	});

src/getCommitMeaning.ts

@@ -9,7 +9,14 @@ const releaseCommitTester =
 
 export function getCommitMeaning(message: string) {
 	// Some types are always meaningful or ignored, regardless of potentially release-like messages
-	const { type } = conventionalCommitsParser.sync(message);
+	// options from https://github.com/conventional-changelog/conventional-changelog/issues/648#issuecomment-704867077
+	const { notes, type } = conventionalCommitsParser.sync(message, {
+		breakingHeaderPattern: /^(\w*)(?:\((.*)\))?!: (.*)$/,
+	} as object);
+	if (notes.some((note) => note.title.match(/^BREAKING[ -]CHANGE$/))) {
+		return "meaningful";
+	}
+
 	if (type) {
 		if (alwaysMeaningfulTypes.has(type)) {
 			return "meaningful";