Why Writing Fewer, Purposeful Tests Can Build More Confidence Than Many

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A developer building a Candidate Tracker job-creation workflow found that application-service tests had grown more complex than the feature they were meant to protect. After review, only three core test cases were kept — covering valid input normalization, invalid input rejection, and orphan-record prevention — because these directly guarded real business rules. The developer argued that mocking every repository method largely proves trivial control-flow logic already enforced by TypeScript, not meaningful behavior. Integration tests and manual end-to-end checks were deemed better suited for verifying persistence and full user workflows. The resulting guideline: test business decisions and real behaviors, add regression tests when actual bugs surface, and never optimize purely for test count or branch coverage.

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