feat(cli): implement print-config cli flag (#2391)

* feat(cli): implement print-config cli flag

* test(cli): normalize difference between node console.log

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

@@ -446,6 +446,7 @@ test('should print help', async () => {
 		Options:
 		  -c, --color          toggle colored output           [boolean] [default: true]
 		  -g, --config         path to the config file                          [string]
+		      --print-config   print resolved config          [boolean] [default: false]
 		  -d, --cwd            directory to execute in
 		                                         [string] [default: (Working Directory)]
 		  -e, --edit           read last commit message from the specified file or
@@ -475,6 +476,27 @@ test('should print version', async () => {
 	expect(actual.stdout).toMatch('@commitlint/cli@');
 });
 
+test('should print config', async () => {
+	const cwd = await gitBootstrap('fixtures/default');
+	const actual = await cli(['--print-config', '--no-color'], {cwd})();
+	const stdout = actual.stdout
+		.replace(/^{[^\n]/g, '{\n  ')
+		.replace(/[^\n]}$/g, '\n}')
+		.replace(/(helpUrl:)\n[ ]+/, '$1 ');
+	expect(stdout).toMatchInlineSnapshot(`
+		"{
+		  extends: [],
+		  formatter: '@commitlint/format',
+		  parserPreset: undefined,
+		  ignores: undefined,
+		  defaultIgnores: undefined,
+		  plugins: {},
+		  rules: { 'type-enum': [ 2, 'never', [ 'foo' ] ] },
+		  helpUrl: 'https://github.com/conventional-changelog/commitlint/#what-is-commitlint'
+		}"
+	`);
+});
+
 async function writePkg(payload: unknown, options: TestOptions) {
 	const pkgPath = path.join(options.cwd, 'package.json');
 	const pkg = JSON.parse(await fs.readFile(pkgPath, 'utf-8'));

@commitlint/cli/src/cli.ts

@@ -6,6 +6,7 @@ import stdin from 'get-stdin';
 import resolveFrom from 'resolve-from';
 import resolveGlobal from 'resolve-global';
 import yargs from 'yargs';
+import util from 'util';
 
 import {CliFlags, Seed} from './types';
 import {
@@ -33,6 +34,11 @@ const cli = yargs
 			description: 'path to the config file',
 			type: 'string',
 		},
+		'print-config': {
+			type: 'boolean',
+			default: false,
+			description: 'print resolved config',
+		},
 		cwd: {
 			alias: 'd',
 			default: process.cwd(),
@@ -123,6 +129,16 @@ main({edit: false, ...cli.argv}).catch((err) => {
 async function main(options: CliFlags) {
 	const raw = options._;
 	const flags = normalizeFlags(options);
+
+	if (flags['print-config']) {
+		const loaded = await load(getSeed(flags), {
+			cwd: flags.cwd,
+			file: flags.config,
+		});
+		console.log(util.inspect(loaded, false, null, options.color));
+		return;
+	}
+
 	const fromStdin = checkFromStdin(raw, flags);
 
 	const input = await (fromStdin
@@ -149,8 +165,10 @@ async function main(options: CliFlags) {
 		throw err;
 	}
 
-	const loadOpts = {cwd: flags.cwd, file: flags.config};
-	const loaded = await load(getSeed(flags), loadOpts);
+	const loaded = await load(getSeed(flags), {
+		cwd: flags.cwd,
+		file: flags.config,
+	});
 	const parserOpts = selectParserOpts(loaded.parserPreset);
 	const opts: LintOptions & {parserOpts: ParserOptions} = {
 		parserOpts: {},

@commitlint/cli/src/types.ts

@@ -14,6 +14,7 @@ export interface CliFlags {
 	to?: string;
 	version?: boolean;
 	verbose?: boolean;
+	'print-config'?: boolean;
 	_: string[];
 	$0: string;
 }

docs/reference-cli.md

@@ -3,31 +3,32 @@
 ```bash
 ❯ npx commitlint --help
 
-@commitlint/cli@8.3.5 - Lint your commit messages
+@commitlint/cli@11.0.0 - Lint your commit messages
 
 [input] reads from stdin if --edit, --env, --from and --to are omitted
 
 Options:
-  --color, -c          toggle colored output           [boolean] [default: true]
-  --config, -g         path to the config file                          [string]
-  --cwd, -d            directory to execute in           [string] [default: cwd]
-  --edit, -e           read last commit message from the specified file or
-                       fallbacks to ./.git/COMMIT_EDITMSG
-                                                       [string] [default: false]
-  --env, -E            check message in the file at path given by environment
+  -c, --color          toggle colored output           [boolean] [default: true]
+  -g, --config         path to the config file                          [string]
+      --print-config   print resolved config          [boolean] [default: false]
+  -d, --cwd            directory to execute in
+                                         [string] [default: (Working Directory)]
+  -e, --edit           read last commit message from the specified file or
+                       fallbacks to ./.git/COMMIT_EDITMSG               [string]
+  -E, --env            check message in the file at path given by environment
                        variable value                                   [string]
-  --extends, -x        array of shareable configurations to extend       [array]
-  --help-url, -H       helpurl in error message                         [string]
-  --from, -f           lower end of the commit range to lint; applies if
+  -x, --extends        array of shareable configurations to extend       [array]
+  -H, --help-url       help url in error message                        [string]
+  -f, --from           lower end of the commit range to lint; applies if
                        edit=false                                       [string]
-  --format, -o         output format of the results                     [string]
-  --parser-preset, -p  configuration preset to use for
+  -o, --format         output format of the results                     [string]
+  -p, --parser-preset  configuration preset to use for
                        conventional-commits-parser                      [string]
-  --quiet, -q          toggle console output          [boolean] [default: false]
-  --to, -t             upper end of the commit range to lint; applies if
+  -q, --quiet          toggle console output          [boolean] [default: false]
+  -t, --to             upper end of the commit range to lint; applies if
                        edit=false                                       [string]
-  --verbose, -V        enable verbose output for reports without problems
+  -V, --verbose        enable verbose output for reports without problems
                                                                        [boolean]
   -v, --version        display version information                     [boolean]
-  -h, --help           Show help                                       [boolean]
+  -h, --help           Show help                                       [boolean]"
 ```