fix(@angular/cli): add choices to command line parser when type is array and has an enum

This commit enhances the command-line parser in `@angular/cli` by adding support for displaying available choices when a command option is of type `array` and has an `enum`.

Author: alan-agius4

packages/angular/cli/src/command-builder/utilities/json-schema.ts

@@ -148,7 +148,7 @@ export async function parseJsonSchemaToOptions(
           if (
             json.isJsonObject(current.items) &&
             typeof current.items.type == 'string' &&
-            ['boolean', 'number', 'string'].includes(current.items.type)
+            isValidTypeForEnum(current.items.type)
           ) {
             return true;
           }
@@ -169,17 +169,15 @@ export async function parseJsonSchemaToOptions(
     }
 
     // Only keep enum values we support (booleans, numbers and strings).
-    const enumValues = ((json.isJsonArray(current.enum) && current.enum) || []).filter((x) => {
-      switch (typeof x) {
-        case 'boolean':
-        case 'number':
-        case 'string':
-          return true;
-
-        default:
-          return false;
-      }
-    }) as (string | true | number)[];
+    const enumValues = (
+      (json.isJsonArray(current.enum) && current.enum) ||
+      (json.isJsonObject(current.items) &&
+        json.isJsonArray(current.items.enum) &&
+        current.items.enum) ||
+      []
+    )
+      .filter((value) => isValidTypeForEnum(typeof value))
+      .sort() as (string | true | number)[];
 
     let defaultValue: string | number | boolean | undefined = undefined;
     if (current.default !== undefined) {
@@ -356,3 +354,8 @@ export function addSchemaOptionsToCommand<T>(
 
   return optionsWithAnalytics;
 }
+
+const VALID_ENUM_TYPES = new Set(['boolean', 'number', 'string']);
+function isValidTypeForEnum(value: string): boolean {
+  return VALID_ENUM_TYPES.has(value);
+}

packages/angular/cli/src/command-builder/utilities/json-schema_spec.ts

@@ -7,7 +7,7 @@
  */
 
 import { json, schema } from '@angular-devkit/core';
-import yargs, { positional } from 'yargs';
+import yargs from 'yargs';
 
 import { addSchemaOptionsToCommand, parseJsonSchemaToOptions } from './json-schema';
 
@@ -74,6 +74,13 @@ describe('parseJsonSchemaToOptions', () => {
           'type': 'string',
           'enum': ['always', 'surprise-me', 'never'],
         },
+        'arrayWithChoices': {
+          'type': 'array',
+          'items': {
+            'type': 'string',
+            'enum': ['always', 'never'],
+          },
+        },
         'extendable': {
           'type': 'object',
           'properties': {},
@@ -100,6 +107,24 @@ describe('parseJsonSchemaToOptions', () => {
       });
     });
 
+    describe('type=array, enum', () => {
+      it('parses valid option value', async () => {
+        expect(
+          await parse(['--arrayWithChoices', 'always', '--arrayWithChoices', 'never']),
+        ).toEqual(
+          jasmine.objectContaining({
+            'arrayWithChoices': ['always', 'never'],
+          }),
+        );
+      });
+
+      it('rejects non-enum values', async () => {
+        await expectAsync(parse(['--arrayWithChoices', 'yes'])).toBeRejectedWithError(
+          /Argument: array-with-choices, Given: "yes", Choices:/,
+        );
+      });
+    });
+
     describe('type=string, enum', () => {
       it('parses valid option value', async () => {
         expect(await parse(['--ssr', 'never'])).toEqual(