add option to customize namespaces

src/environment-base.ts

@@ -50,6 +50,13 @@ const ENVIRONMENT_VERSION = require('../package.json').version;
 
 const debug = createdLogger('yeoman:environment');
 
+export type EnvironmentLookupOptions = LookupOptions & {
+  /** Add a scope to the namespace if there is no scope */
+  registerToScope?: string;
+  /** Customize the namespace to be registered */
+  customizeNamespace?: (ns?: string) => string;
+};
+
 export type EnvironmentOptions = BaseEnvironmentOptions &
   Omit<TerminalAdapterOptions, 'promptModule'> & {
     adapter?: InputOutputAdapter;
@@ -600,8 +607,13 @@ export default class EnvironmentBase extends EventEmitter implements BaseEnviron
    * So this index file `node_modules/generator-dummy/lib/generators/yo/index.js` would be
    * registered as `dummy:yo` generator.
    */
-  async lookup(options?: LookupOptions & { registerToScope?: string }): Promise<LookupGeneratorMeta[]> {
-    const { registerToScope, lookups = this.lookups, ...remainingOptions } = options ?? { localOnly: false };
+  async lookup(options?: EnvironmentLookupOptions): Promise<LookupGeneratorMeta[]> {
+    const {
+      registerToScope,
+      customizeNamespace = (ns: string) => ns,
+      lookups = this.lookups,
+      ...remainingOptions
+    } = options ?? { localOnly: false };
     options = {
       ...remainingOptions,
       lookups,
@@ -615,11 +627,11 @@ export default class EnvironmentBase extends EventEmitter implements BaseEnviron
         repositoryPath = join(repositoryPath, '..');
       }
 
-      let namespace = asNamespace(relative(repositoryPath, filePath), { lookups });
+      let namespace = customizeNamespace(asNamespace(relative(repositoryPath, filePath), { lookups }));
       try {
         const resolved = realpathSync(filePath);
         if (!namespace) {
-          namespace = asNamespace(resolved, { lookups });
+          namespace = customizeNamespace(asNamespace(resolved, { lookups }));
         }
 
         if (registerToScope && !namespace.startsWith('@')) {

test/__snapshots__/resolver.js.snap

@@ -930,6 +930,21 @@ exports[`Environment Resolver #lookup() with options with 3 packagePaths 1`] = `
 }
 `;
 
+exports[`Environment Resolver #lookup() with options with customizeNamespace 1`] = `
+{
+  "custom:app": {
+    "importGenerator": [Function],
+    "importModule": [Function],
+    "instantiate": [Function],
+    "instantiateHelp": [Function],
+    "namespace": "custom:app",
+    "packageNamespace": "custom",
+    "packagePath": "fixtures/lookup-custom/node_modules/generator-module",
+    "resolved": "fixtures/generator-module/generators/app/index.js",
+  },
+}
+`;
+
 exports[`Environment Resolver #lookup() with options with npmPaths 1`] = `
 {
   "@scoped/scoped:app": {

test/resolver.js

@@ -399,6 +399,19 @@ describe('Environment Resolver', async function () {
       assert.ok(this.env.getRegisteredPackages().length === 1);
     });
 
+    it('with customizeNamespace', async function () {
+      await this.env.lookup({
+        localOnly: true,
+        packagePaths: ['node_modules/generator-module'],
+        customizeNamespace: ns => ns.replace('module', 'custom'),
+      });
+
+      expect(toRelativeMeta(this.env.getGeneratorsMeta())).toMatchSnapshot();
+
+      assert.ok(await this.env.get('custom:app'));
+      assert.ok(this.env.getRegisteredPackages().length === 1);
+    });
+
     it('with scope and packagePaths', async function () {
       await this.env.lookup({
         localOnly: true,