feat(load): add cosmiconfig typescript loader

@commitlint/load/fixtures/recursive-extends-ts/commitlint.config.ts

@@ -0,0 +1,9 @@
+import type {UserConfig} from './types';
+
+const Configuration: UserConfig = {
+	extends: ['./first-extended'],
+	rules: {
+		zero: [0, 'never', 'zero']
+	}
+};
+module.exports = Configuration;

@commitlint/load/fixtures/recursive-extends-ts/first-extended/index.ts

@@ -0,0 +1,7 @@
+import type {UserConfig} from '../types';
+module.exports = {
+	extends: ['./second-extended'],
+	rules: {
+		one: [1, 'never', 'one']
+	}
+} as UserConfig;

@commitlint/load/fixtures/recursive-extends-ts/first-extended/second-extended/index.ts

@@ -0,0 +1,6 @@
+import type {UserConfig} from '../../types';
+module.exports = {
+	rules: {
+		two: [2, 'never', 'two']
+	}
+} as UserConfig;

@commitlint/load/fixtures/recursive-extends-ts/types.ts

@@ -0,0 +1,11 @@
+export interface UserConfig {
+	extends?: string[];
+	formatter?: string;
+	rules?: any;
+	parserPreset?: any;
+	ignores?: ((commit: string) => boolean)[];
+	defaultIgnores?: boolean;
+	plugins?: (string | Plugin)[];
+	helpUrl?: string;
+	prompt?: any;
+}

@commitlint/load/src/load.test.ts

@@ -248,6 +248,22 @@ test('recursive extends with package.json file', async () => {
 	});
 });
 
+test('recursive extends with ts file', async () => {
+	const cwd = await gitBootstrap('fixtures/recursive-extends-ts');
+	const actual = await load({}, {cwd});
+
+	expect(actual).toMatchObject({
+		formatter: '@commitlint/format',
+		extends: ['./first-extended'],
+		plugins: {},
+		rules: {
+			zero: [0, 'never', 'zero'],
+			one: [1, 'never', 'one'],
+			two: [2, 'never', 'two'],
+		},
+	});
+});
+
 test('parser preset overwrites completely instead of merging', async () => {
 	const cwd = await gitBootstrap('fixtures/parser-preset-override');
 	const actual = await load({}, {cwd});