refactor(migrations): handle safe property reads in signal input migr…

…ation (angular#57318)

As of this commit, the migration will also inspect safe property reads
and migrate them, if they reference an input that is being migrated.

PR Close angular#57318

packages/core/schematics/migrations/signal-migration/src/input_detection/template_reference_visitor.ts

@@ -17,6 +17,7 @@ import {
   PropertyRead,
   PropertyWrite,
   RecursiveAstVisitor,
+  SafePropertyRead,
   ThisReceiver,
   TmplAstBoundAttribute,
   TmplAstBoundEvent,
@@ -274,12 +275,15 @@ export class TemplateExpressionReferenceVisitor<ExprContext> extends RecursiveAs
     super.visitLiteralMap(ast, context);
   }
 
-  // TODO: Consider safe property reads/writes.
-
   override visitPropertyRead(ast: PropertyRead) {
     this._inspectPropertyAccess(ast);
     super.visitPropertyRead(ast, null);
   }
+  override visitSafePropertyRead(ast: SafePropertyRead) {
+    this._inspectPropertyAccess(ast);
+    super.visitPropertyRead(ast, null);
+  }
+
   override visitPropertyWrite(ast: PropertyWrite) {
     this._inspectPropertyAccess(ast);
     super.visitPropertyWrite(ast, null);

packages/core/schematics/migrations/signal-migration/test/golden-test/safe_property_reads.ts

@@ -0,0 +1,22 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+// tslint:disable
+
+import {Component, Input} from '@angular/core';
+
+@Component({
+  template: `
+    {{bla?.myInput}}
+  `,
+})
+class WithSafePropertyReads {
+  @Input() myInput = 0;
+
+  bla: this | undefined = this;
+}

packages/core/schematics/migrations/signal-migration/test/golden.txt

@@ -751,6 +751,30 @@ import { input } from '@angular/core';
 class Required {
   simpleInput = input.required<string>();
 }
+@@@@@@ safe_property_reads.ts @@@@@@
+
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+// tslint:disable
+
+import { Component, input } from '@angular/core';
+
+@Component({
+  template: `
+    {{bla?.myInput()}}
+  `,
+})
+class WithSafePropertyReads {
+  myInput = input(0);
+
+  bla: this | undefined = this;
+}
 @@@@@@ scope_sharing.ts @@@@@@
 
 // tslint:disable

packages/core/schematics/migrations/signal-migration/test/golden_best_effort.txt

@@ -751,6 +751,30 @@ import { input } from '@angular/core';
 class Required {
   simpleInput = input.required<string>();
 }
+@@@@@@ safe_property_reads.ts @@@@@@
+
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+// tslint:disable
+
+import { Component, input } from '@angular/core';
+
+@Component({
+  template: `
+    {{bla?.myInput()}}
+  `,
+})
+class WithSafePropertyReads {
+  myInput = input(0);
+
+  bla: this | undefined = this;
+}
 @@@@@@ scope_sharing.ts @@@@@@
 
 // tslint:disable