Karate match contains vs match equals for dynamic JSON fields

Goal

Validate JSON API responses in Karate DSL while tolerating server-added dynamic fields such as timestamps and generated IDs.

The project uses Karate’s built-in JSON matchers. `match equals` requires an exact body match and fails when the response includes any undeclared key. `match contains` asserts only the expected subset and ignores extra fields, but it does not prove that no additional fields exist. The team needs to choose one default matcher for contract tests without introducing brittleness or hiding response bloat.

Assuming a recent stable Karate release where both operators behave consistently for JSON, which matcher should be the project default, and under what conditions should the stricter operator override it?

• Does `match contains` sufficiently protect against accidental field removal when expected keys are nested?
• Should `match equals` be reserved for endpoints whose schema explicitly forbids extra properties?
• How should custom matchers or project-level overrides affect this default decision?