Router PR Review Guidelines

When reviewing pull requests that modify the Angular Router (packages/router), pay special attention to the following:

• Timing Sensitivity: The router is extremely sensitive to timing changes. Any changes that alter the asynchronous timing of navigations, resolvers, or guards are almost always breaking changes and must be scrutinized carefully.
• Testing Practices: Tests should usually use the RouterTestingHarness. Many existing tests are older and do not use this harness. Do not blindly follow the shape of existing tests when writing or reviewing new ones; encourage the use of modern testing utilities.
• Feature Justification: Changes to router core code should be well-justified. Consider whether the change is proven to be a core developer ask, such as resolving a highly upvoted GitHub issue or addressing a critical bug.