fix(forms): FormBuilder.group return right type with shorthand parameters. (#48084)

JeanMeche · dylhunn · commit a12a12027202 · 2022-11-17T11:04:54.000-08:00
Extract AbstractControlOptions from type when used in shorthand parameters on FormBuilder.group Fixes 48073 PR Close #48084
diff --git a/packages/forms/src/form_builder.ts b/packages/forms/src/form_builder.ts
@@ -38,6 +38,14 @@ type ValidatorConfig = ValidatorFn|AsyncValidatorFn|ValidatorFn[]|AsyncValidator
  */
 type PermissiveControlConfig<T> = Array<T|FormControlState<T>|ValidatorConfig>;
 
+/**
+ * Helper type to allow the compiler to accept [XXXX, { updateOn: string }] as a valid shorthand
+ * argument for .group()
+ */
+interface PermissiveAbstractControlOptions extends Omit<AbstractControlOptions, 'updateOn'> {
+  updateOn?: string;
+}
+
 /**
  * ControlConfig<T> is a tuple containing a value of type T, plus optional validators and async
  * validators.
@@ -82,7 +90,7 @@ export type ɵElement<T, N extends null> =
   // FormControlState object container, which produces a nullable control.
   [T] extends [FormControlState<infer U>] ? FormControl<U|N> :
   // A ControlConfig tuple, which produces a nullable control.
-  [T] extends [PermissiveControlConfig<infer U>] ? FormControl<Exclude<U, ValidatorConfig>|N> :
+  [T] extends [PermissiveControlConfig<infer U>] ? FormControl<Exclude<U, ValidatorConfig| PermissiveAbstractControlOptions>|N> :
   FormControl<T|N>;
 
 // clang-format on
diff --git a/packages/forms/test/form_builder_spec.ts b/packages/forms/test/form_builder_spec.ts
@@ -189,6 +189,22 @@ describe('Form Builder', () => {
     expect(g.asyncValidator).toBe(null);
   });
 
+  it('should create groups with shorthand parameters and with right typings', () => {
+    const form = b.group({
+      shorthand: [3, Validators.required],
+      shorthand2: [5, {validators: Validators.required}],
+    });
+
+    expect((form.get('shorthand')?.value)).toEqual(3);
+    expect(((form.get('shorthand2')!.value ?? 0) + 0)).toEqual(5);
+
+
+    const form2 = b.group({
+      shorthand2: [5, {updateOn: 'blur'}],
+    });
+    expect(((form2.get('shorthand2')!.value ?? 0) + 0)).toEqual(5);
+  });
+
   it('should create control arrays', () => {
     const c = b.control('three');
     const e = b.control(null);
