Presubmit

Presubmit is a term used in software development to describe the set of checks and validations performed on a code change before it is submitted for review or merged into the main repository. The goal is to catch issues early and ensure adherence to project standards, compatibility with the base code, and absence of obvious defects. Presubmit checks can be executed in different places: locally by the developer through pre-submit hooks or scripts, in a code review system before a patch set is accepted, or in continuous integration pipelines after submission but before merging.

Typical presubmit checks include build and compilation tests, unit tests, and integration tests; they also commonly cover static analysis, linting, and type checking. Additional verifications may involve formatting and style conformity, license and copyright headers, dependency integrity, and checks for security or known vulnerable patterns. Some environments also audit for sensitive data exposure or ensure documentation updates accompany code changes.

Process and workflow considerations vary by organization. A patch that passes presubmit checks is typically allowed to proceed to code review or be merged, while failing checks block submission until issues are resolved. In some workflows, presubmit runs locally or at submission time, and may be reinforced by server-side continuous integration.

Presubmit serves to improve code quality, reduce regressions, and streamline reviews by catching defects early. It can, however, introduce delays if the checks are overly strict or slow, and may produce false positives or require ongoing maintenance to reflect evolving project standards.