Angular Upgrade Templates Angular V20 Template Operator Compat

---
id: angular.upgrade.templates.angular-v20-template-operator-compat
name: Angular v20 Template Operator Compatibility
description: >
  Review Angular 20 templates for operator and identifier compatibility when property names such as `in` or `void` collide with JavaScript operators or when parenthesized optional and nullish expressions may throw. Use when template syntax or selector names need safe compatibility cleanup.
stack:
  - Angular
  - TypeScript
category: templates
status: stable
version: 0.10.0
owner: NgAutoPilot
triggers:
  - template operator compatibility
  - in operator
  - void operator
  - parenthesized expressions
compatibility:
  angular:
    min: "20"
---

# Angular v20 Template Operator Compatibility

## Purpose

Review Angular 20 templates for operator and identifier compatibility.

## When to Use

- Templates use names that collide with `in` or `void`.
- Templates use parenthesized optional or nullish expressions.
- The app is stable on Angular 20.

## When Not to Use

- The app has no risky template expressions.
- The app is still in a version hop.

## Required Inputs

- templates
- template refs
- property names
- optional/nullish expressions

## Procedure

1. Identify colliding template names.
2. Rename refs or use safe property access.
3. Review parenthesized expressions.
4. Validate rendering.

## Do

- Prefer explicit and safe template expressions.
- Rename colliding refs.

## Do Not

- Do not leave ambiguous identifiers in templates.
- Do not mix this with the version hop.

## Review Checklist

- [ ] Colliding names are removed or escaped.
- [ ] Parenthesized expressions are safe.
- [ ] Rendering passes.

## Expected Output

1. Template compatibility summary.
2. Rename list.
3. Render/test result.

## Exit Criteria

- Template operator risk is explicit.