Add preferred prefix support

src/prefixer/RopmModule.spec.ts

@@ -68,6 +68,46 @@ describe('RopmModule', () => {
             await module.init();
             expect(module.isValid).to.be.false;
         });
+
+        it('uses preferredPrefix when no alias is given', async () => {
+            const [promises] = createProjects(hostDir, hostDir, {
+                name: 'host',
+                dependencies: [{
+                    name: '@rokucommunity/promises',
+                    ropm: {
+                        preferredPrefix: 'promises'
+                    }
+                }]
+            });
+            await promises.init();
+            expect(promises.ropmModuleName).to.equal('promises');
+        });
+
+        it('ignores preferredPrefix when a user alias is given', async () => {
+            const [promises] = createProjects(hostDir, hostDir, {
+                name: 'host',
+                dependencies: [{
+                    name: '@rokucommunity/promises',
+                    alias: 'mypkg',
+                    ropm: {
+                        preferredPrefix: 'promises'
+                    }
+                }]
+            });
+            await promises.init();
+            expect(promises.ropmModuleName).to.equal('mypkg');
+        });
+
+        it('uses default derived prefix when preferredPrefix is absent', async () => {
+            const [promises] = createProjects(hostDir, hostDir, {
+                name: 'host',
+                dependencies: [{
+                    name: '@rokucommunity/promises'
+                }]
+            });
+            await promises.init();
+            expect(promises.ropmModuleName).to.equal('rokucommunity_promises');
+        });
     });
 
     describe('createPrefixMap', () => {

src/prefixer/RopmModule.ts

@@ -147,6 +147,16 @@ export class RopmModule {
 
         this.npmModuleName = this.packageJson.name;
 
+        //detect if the user supplied an explicit alias at install time by comparing the local name vs the resolved package name
+        const hasUserAlias = this.npmAliasName.toLowerCase() !== this.npmModuleName.toLowerCase();
+
+        //apply preferredPrefix only when the user did not provide an explicit alias
+        if (!hasUserAlias && this.packageJson.ropm?.preferredPrefix) {
+            const defaultPrefix = this.ropmModuleName;
+            this.ropmModuleName = this.packageJson.ropm.preferredPrefix;
+            this.logger.info(`Using preferredPrefix "${this.ropmModuleName}" for "${this.npmModuleName}" (overrides default prefix "${defaultPrefix}")`);
+        }
+
         //disallow using `noprefix` within dependencies
         if (this.packageJson.ropm?.noprefix) {
             this.logger.error(`Using "ropm.noprefix" in a ropm module is forbidden: "${path.join(this.moduleDir, 'package.json')}`);

src/util.ts

@@ -348,6 +348,12 @@ export interface RopmOptions {
      */
     noprefix?: string[];
 
+    /**
+     * A preferred prefix for this module to suggest to consumers. When a consumer installs this module
+     * without an explicit alias, this prefix will be used instead of the auto-derived one.
+     */
+    preferredPrefix?: string;
+
     /**
      * What level of ropm's internal logging should be performed
      */