How do you deal with unstable tests when the contract or parameter changes?

If the contract or parameter has changed, causing tests to become unstable, you should:

• First, analyze the changes in the contract and understand which tests are affected.
• Update test data and scenarios according to the new contract.
• Use contract versioning so that tests can work with different API versions.
• Implement contract testing (e.g., using Pact) to automatically verify compliance between services.
• Add checks in tests for parameter correctness and error handling to prevent tests from failing due to unexpected changes.
• If necessary, use mock services with current contracts.

Example: if the date format in the API changes from "YYYY-MM-DD" to "DD.MM.YYYY", update parsing and checks in tests to match the new format.