fix(config-lerna-scopes): ignore packages without names (#2514)

Some packages now include package.json file in sub-directories which dont contain names

@commitlint/config-lerna-scopes/fixtures/modules/lerna.json

@@ -0,0 +1,5 @@
+{
+  "lerna": "4",
+  "version": "1.0.0",
+  "packages": ["packages/*"]
+}

@commitlint/config-lerna-scopes/fixtures/modules/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "basic",
+  "version": "1.0.0",
+  "devDependencies": {
+    "lerna": "^4.0.0"
+  }
+}

@commitlint/config-lerna-scopes/fixtures/modules/packages/a/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "a",
+  "version": "1.0.0"
+}

@commitlint/config-lerna-scopes/fixtures/modules/packages/module/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

@commitlint/config-lerna-scopes/index.js

@@ -49,6 +49,7 @@ function getPackages(context) {
 		.then((packages) => {
 			return packages
 				.map((pkg) => pkg.name)
+				.filter(Boolean)
 				.map((name) => (name.charAt(0) === '@' ? name.split('/')[1] : name));
 		});
 }

@commitlint/config-lerna-scopes/index.test.js

@@ -60,6 +60,14 @@ test('returns expected value for basic lerna repository', async () => {
 	expect(value).toEqual(['a', 'b']);
 });
 
+test('returns expected value for lerna repository containing modules', async () => {
+	const {'scope-enum': fn} = config.rules;
+	const cwd = await lerna.bootstrap('modules', __dirname);
+
+	const [, , value] = await fn({cwd});
+	expect(value).toEqual(['a']);
+});
+
 test('returns expected value for scoped lerna repository', async () => {
 	const {'scope-enum': fn} = config.rules;
 	const cwd = await lerna.bootstrap('scoped', __dirname);