feat(cli): implement new --last CLI flag

The upgrade of ES2017 to ES2022 is because of the use of
`Object.hasOwn` API which is less ugly than hardcoding
`undefined`.

Author: Mersho

@commitlint/cli/src/cli.test.ts

@@ -55,7 +55,7 @@ test('should produce success output with --verbose flag', async () => {
 test('should produce last commit and success output with --verbose flag', async () => {
 	const cwd = await gitBootstrap('fixtures/simple');
 	await execa('git', ['add', 'commitlint.config.js'], {cwd});
-	const commit = await execa(
+	await execa(
 		'git',
 		['commit', '-m', '"test: this should work"'],
 		{cwd}
@@ -543,6 +543,7 @@ test('should print help', async () => {
 		  -H, --help-url       help url in error message  [string]
 		  -f, --from           lower end of the commit range to lint; applies if edit=false  [string]
 		      --git-log-args   additional git log arguments as space separated string, example '--first-parent --cherry-pick'  [string]
+		  -l, --last           just analyze the last commit; applies if edit=false  [boolean]
 		  -o, --format         output format of the results  [string]
 		  -p, --parser-preset  configuration preset to use for conventional-commits-parser  [string]
 		  -q, --quiet          toggle console output  [boolean] [default: false]

@commitlint/cli/src/cli.ts

@@ -95,6 +95,11 @@ const cli = yargs(process.argv.slice(2))
 				"additional git log arguments as space separated string, example '--first-parent --cherry-pick'",
 			type: 'string',
 		},
+		last: {
+			alias: 'l',
+			description: 'just analyze the last commit; applies if edit=false',
+			type: 'boolean',
+		},
 		format: {
 			alias: 'o',
 			description: 'output format of the results',
@@ -214,15 +219,34 @@ async function main(args: MainArgs): Promise<void> {
 
 	const fromStdin = checkFromStdin(raw, flags);
 
-	const input = await (fromStdin
-		? stdin()
-		: read({
-				to: flags.to,
-				from: flags.from,
-				edit: flags.edit,
-				cwd: flags.cwd,
-				gitLogArgs: flags['git-log-args'],
-		  }));
+	if (
+		Object.hasOwn(flags, 'last') &&
+		(Object.hasOwn(flags, 'from') || Object.hasOwn(flags, 'to') || flags.edit)
+	) {
+		const err = new CliError(
+			'Please use the --last flag alone. The --last flag should not be used with --to or --from or --edit.',
+			pkg.name
+		);
+		cli.showHelp('log');
+		console.log(err.message);
+		throw err;
+	}
+
+	let input;
+	if (Object.hasOwn(flags, 'last')) {
+		const executeGitCommand = await execa('git', ['log', '-1', '--pretty=%B']);
+		input = executeGitCommand.stdout;
+	} else {
+		input = await (fromStdin
+			? stdin()
+			: read({
+					to: flags.to,
+					from: flags.from,
+					edit: flags.edit,
+					cwd: flags.cwd,
+					gitLogArgs: flags['git-log-args'],
+			  }));
+	}
 
 	const messages = (Array.isArray(input) ? input : [input])
 		.filter((message) => typeof message === 'string')
@@ -231,7 +255,7 @@ async function main(args: MainArgs): Promise<void> {
 
 	if (messages.length === 0 && !checkFromRepository(flags)) {
 		const err = new CliError(
-			'[input] is required: supply via stdin, or --env or --edit or --from and --to',
+			'[input] is required: supply via stdin, or --env or --edit or --last or --from and --to',
 			pkg.name
 		);
 		cli.showHelp('log');
@@ -374,7 +398,11 @@ function checkFromEdit(flags: CliFlags): boolean {
 }
 
 function checkFromHistory(flags: CliFlags): boolean {
-	return typeof flags.from === 'string' || typeof flags.to === 'string';
+	return (
+		typeof flags.from === 'string' ||
+		typeof flags.to === 'string' ||
+		typeof flags.last === 'boolean'
+	);
 }
 
 function normalizeFlags(flags: CliFlags): CliFlags {

@commitlint/cli/src/types.ts

@@ -9,6 +9,7 @@ export interface CliFlags {
 	'help-url'?: string;
 	from?: string;
 	'git-log-args'?: string;
+	last?: boolean;
 	format?: string;
 	'parser-preset'?: string;
 	quiet: boolean;

tsconfig.shared.json

@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
-    "target": "ES2017",
-    "lib": ["es2017"],
+    "target": "ES2022",
+    "lib": ["es2022"],
     "declaration": true,
     "declarationMap": true,
     "sourceMap": true,