cli-node: refactor role utils into PackageRoles + document, move stuff back

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/cli/src/lib/role.test.ts

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import mockFs from 'mock-fs';
+import { Command } from 'commander';
+import { findRoleFromCommand } from './role';
+
+describe('findRoleFromCommand', () => {
+  function mkCommand(args: string) {
+    const parsed = new Command()
+      .option('--role <role>', 'test role')
+      .parse(['node', 'entry.js', ...args.split(' ')]) as Command;
+    return parsed.opts();
+  }
+
+  beforeEach(() => {
+    mockFs({
+      'package.json': JSON.stringify({
+        name: 'test',
+        backstage: {
+          role: 'web-library',
+        },
+      }),
+    });
+  });
+
+  afterEach(() => {
+    mockFs.restore();
+  });
+
+  it('provides role info by role', async () => {
+    await expect(findRoleFromCommand(mkCommand(''))).resolves.toEqual(
+      'web-library',
+    );
+
+    await expect(
+      findRoleFromCommand(mkCommand('--role node-library')),
+    ).resolves.toEqual('node-library');
+
+    await expect(
+      findRoleFromCommand(mkCommand('--role invalid')),
+    ).rejects.toThrow(`Unknown package role 'invalid'`);
+  });
+});

packages/cli/src/lib/role.ts

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import fs from 'fs-extra';
+import { OptionValues } from 'commander';
+import { paths } from './paths';
+
+export async function findRoleFromCommand(
+  opts: OptionValues,
+): Promise<PackageRole> {
+  if (opts.role) {
+    return getRoleInfo(opts.role)?.role;
+  }
+
+  const pkg = await fs.readJson(paths.resolveTarget('package.json'));
+  const info = getRoleFromPackage(pkg);
+  if (!info) {
+    throw new Error(`Target package must have 'backstage.role' set`);
+  }
+  return info;
+}