fix(@angular-devkit/core): only invoke smart default provider when value is undefined

Previously, `CoreSchemaRegistry._applySmartDefaults` invoked the smart default provider unconditionally before `CoreSchemaRegistry._set` checked whether the target property already had a defined value. This caused smart default providers to be evaluated even when an option was explicitly provided.

(cherry picked from commit c44762f)

Author: alan-agius4

packages/angular_devkit/core/src/json/schema/registry.ts

@@ -585,11 +585,11 @@ export class CoreSchemaRegistry implements SchemaRegistry {
     for (const path in answers) {
       const pathFragments = path.split('/').slice(1);
 
-      CoreSchemaRegistry._set(data, pathFragments, answers[path], null, undefined, true);
+      await CoreSchemaRegistry._set(data, pathFragments, answers[path], null, undefined, true);
     }
   }
 
-  private static _set(
+  private static async _set(
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     data: any,
     fragments: string[],
@@ -598,7 +598,7 @@ export class CoreSchemaRegistry implements SchemaRegistry {
     parent: any = null,
     parentProperty?: string,
     force?: boolean,
-  ): void {
+  ): Promise<void> {
     for (let index = 0; index < fragments.length; index++) {
       const fragment = fragments[index];
       if (/^i\d+$/.test(fragment)) {
@@ -607,7 +607,7 @@ export class CoreSchemaRegistry implements SchemaRegistry {
         }
 
         for (let dataIndex = 0; dataIndex < data.length; dataIndex++) {
-          CoreSchemaRegistry._set(
+          await CoreSchemaRegistry._set(
             data[dataIndex],
             fragments.slice(index + 1),
             value,
@@ -629,7 +629,12 @@ export class CoreSchemaRegistry implements SchemaRegistry {
     }
 
     if (parent && parentProperty && (force || parent[parentProperty] === undefined)) {
-      parent[parentProperty] = value;
+      let resolvedValue = typeof value === 'function' ? value() : value;
+      if (isObservable(resolvedValue)) {
+        resolvedValue = await lastValueFrom(resolvedValue);
+      }
+
+      parent[parentProperty] = resolvedValue;
     }
   }
 
@@ -644,12 +649,7 @@ export class CoreSchemaRegistry implements SchemaRegistry {
         continue;
       }
 
-      let value = source(schema);
-      if (isObservable(value)) {
-        value = (await lastValueFrom(value)) as {};
-      }
-
-      CoreSchemaRegistry._set(data, fragments, value);
+      await CoreSchemaRegistry._set(data, fragments, () => source(schema));
     }
   }
 

packages/angular_devkit/core/src/json/schema/registry_spec.ts

@@ -305,6 +305,29 @@ describe('CoreSchemaRegistry', () => {
     expect(data.obj.deep.arr).toEqual([1, 2, 3]);
   });
 
+  it('does not call smart default provider when value is already defined', async () => {
+    const registry = new CoreSchemaRegistry();
+    const provider = jasmine.createSpy('provider').and.returnValue('default-val');
+    registry.addSmartDefaultProvider('test', provider);
+
+    const validator = await registry.compile({
+      properties: {
+        prop: {
+          type: 'string',
+          $default: {
+            $source: 'test',
+          },
+        },
+      },
+    });
+
+    const data = { prop: 'explicit-val' };
+    const result = await validator(data);
+    expect(result.success).toBe(true);
+    expect(data.prop).toBe('explicit-val');
+    expect(provider).not.toHaveBeenCalled();
+  });
+
   it('works with true as a schema and post-transforms', async () => {
     const registry = new CoreSchemaRegistry();
     registry.addPostTransform(addUndefinedDefaults);