fix(@angular/cli): register schematic aliases when providing collection name in ng generate.

Previously, schematic aliases were not registered when a collection name was provided to `ng generate`.  Example: `ng generate c` where `c` is an alias for `component` would work, but `ng generate @schematics/angular:c` would fail. This commits fixes the schematic registration to handle the latter case.

Closes #24518

Author: alan-agius4

packages/angular/cli/src/commands/generate/cli.ts

@@ -165,6 +165,7 @@ export class GenerateCommandModule
    */
   private async *getSchematics(): AsyncGenerator<{
     schematicName: string;
+    schematicAliases?: Set<string>;
     collectionName: string;
   }> {
     const seenNames = new Set<string>();
@@ -176,7 +177,10 @@ export class GenerateCommandModule
         // If a schematic with this same name is already registered skip.
         if (!seenNames.has(schematicName)) {
           seenNames.add(schematicName);
-          yield { schematicName, collectionName };
+          const { aliases } = collection.description.schematics[schematicName];
+          const schematicAliases = aliases && new Set(aliases);
+
+          yield { schematicName, schematicAliases, collectionName };
         }
       }
     }
@@ -196,8 +200,11 @@ export class GenerateCommandModule
       this.context.args.positional[1],
     );
 
-    for await (const { schematicName, collectionName } of this.getSchematics()) {
-      if (schematicName === schematicNameFromArgs) {
+    for await (const { schematicName, collectionName, schematicAliases } of this.getSchematics()) {
+      if (
+        schematicNameFromArgs &&
+        (schematicName === schematicNameFromArgs || schematicAliases?.has(schematicNameFromArgs))
+      ) {
         return [[schematicName, collectionName]];
       }
 

tests/legacy-cli/e2e/tests/generate/schematic-aliases.ts

@@ -0,0 +1,15 @@
+import { ng } from '../../utils/process';
+
+export default async function () {
+  // Verify that there are no duplicate options
+  const schematicNameVariation = [
+    'component',
+    'c',
+    '@schematics/angular:component',
+    '@schematics/angular:c',
+  ];
+
+  for (const schematic of schematicNameVariation) {
+    await ng('generate', schematic, 'comp-name', '--display-block', '--dry-run');
+  }
+}