fix(@angular/cli): handle oneOf when converting schema to yargs options

This change fixes JSONSchemas where `oneOf` is placed at the root of the
schema rather than in an array's `items`. This allows an array to be
passed via the command-line, but additional types to be represented via
configuration.

Author: terencehonles

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

@@ -130,21 +130,22 @@ function isStringMap(node: json.JsonObject): boolean {
   );
 }
 
-const SUPPORTED_PRIMITIVE_TYPES = new Set(['boolean', 'number', 'string']);
+const SUPPORTED_PRIMITIVE_TYPES = new Set(['boolean', 'number', 'string'] as const);
+type SupportedPrimitiveType = Parameters<typeof SUPPORTED_PRIMITIVE_TYPES.add>[0];
 
 /**
  * Checks if a string is a supported primitive type.
  * @param value The string to check.
  * @returns `true` if the string is a supported primitive type, otherwise `false`.
  */
-function isSupportedPrimitiveType(value: string): boolean {
-  return SUPPORTED_PRIMITIVE_TYPES.has(value);
+function isSupportedPrimitiveType(value: string): value is SupportedPrimitiveType {
+  return SUPPORTED_PRIMITIVE_TYPES.has(value as any);
 }
 
 /**
  * Recursively checks if a JSON schema for an array's items is a supported primitive type.
  * It supports `oneOf` and `anyOf` keywords.
- * @param schema The JSON schema for the array's items.
+ * @param schema The JSON schema to check.
  * @returns `true` if the schema is a supported primitive type, otherwise `false`.
  */
 function isSupportedArrayItemSchema(schema: json.JsonObject): boolean {
@@ -156,6 +157,10 @@ function isSupportedArrayItemSchema(schema: json.JsonObject): boolean {
     return true;
   }
 
+  if (isJsonObject(schema.items)) {
+    return isSupportedArrayItemSchema(schema.items);
+  }
+
   if (json.isJsonArray(schema.items)) {
     return schema.items.some((item) => isJsonObject(item) && isSupportedArrayItemSchema(item));
   }
@@ -177,6 +182,40 @@ function isSupportedArrayItemSchema(schema: json.JsonObject): boolean {
   return false;
 }
 
+/**
+ * Recursively finds the first supported array primitive type for the given JSON schema.
+ * It supports `oneOf` and `anyOf` keywords.
+ * @param schema The JSON schema to inspect.
+ * @returns The supported primitive type or 'string' if none is found.
+ */
+function getSupportedArrayType(schema: json.JsonObject): SupportedPrimitiveType {
+  if (typeof schema.type === 'string' && isSupportedPrimitiveType(schema.type)) {
+    return schema.type;
+  }
+
+  if (json.isJsonArray(schema.enum)) {
+    return 'string';
+  }
+
+  if (isJsonObject(schema.items)) {
+    const result = getSupportedArrayType(schema.items);
+    if (result) return result;
+  }
+
+  for (const key of ['items', 'oneOf', 'anyOf']) {
+    if (json.isJsonArray(schema[key])) {
+      for (const item in schema[key]) {
+        if (isJsonObject(item)) {
+          const result = getSupportedArrayType(item);
+          if (result) return result;
+        }
+      }
+    }
+  }
+
+  return 'string';
+}
+
 /**
  * Gets the supported types for a JSON schema node.
  * @param current The JSON schema node to get the supported types for.
@@ -198,7 +237,7 @@ function getSupportedTypes(
       case 'string':
         return true;
       case 'array':
-        return isJsonObject(current.items) && isSupportedArrayItemSchema(current.items);
+        return isSupportedArrayItemSchema(current);
       case 'object':
         return isStringMap(current);
       default:
@@ -377,9 +416,13 @@ export async function parseJsonSchemaToOptions(
             type: 'array',
             itemValueType: 'string',
           }
-        : {
-            type,
-          }),
+        : type === 'array'
+          ? {
+              type: getSupportedArrayType(current),
+            }
+          : {
+              type,
+            }),
     };
 
     options.push(option);

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

@@ -116,6 +116,9 @@ describe('parseJsonSchemaToOptions', () => {
               ],
             },
           },
+          'oneOfAtRoot': {
+            'oneOf': [{ 'type': 'array', 'items': { 'type': 'string' } }, { 'type': 'boolean' }],
+          },
         },
       };
       const registry = new schema.CoreSchemaRegistry();
@@ -199,6 +202,27 @@ describe('parseJsonSchemaToOptions', () => {
       });
     });
 
+    describe('type=array, oneOf at root', () => {
+      it('parses valid option value', async () => {
+        expect(
+          await parse([
+            '--oneOfAtRoot',
+            'first',
+            '--oneOfAtRoot',
+            'second',
+            '--oneOfAtRoot',
+            'third',
+          ]),
+        ).toEqual(jasmine.objectContaining({ 'oneOfAtRoot': ['first', 'second', 'third'] }));
+      });
+
+      it('parses --no prefix', async () => {
+        expect(await parse(['--no-oneOfAtRoot'])).toEqual(
+          jasmine.objectContaining({ 'oneOfAtRoot': false }),
+        );
+      });
+    });
+
     describe('type=string, enum', () => {
       it('parses valid option value', async () => {
         expect(await parse(['--ssr', 'never'])).toEqual(