go generate: Usage, Options & Common CI Errors

Run the code generators embedded in your source.

go generate scans for //go:generate directives and runs the commands they specify. It is never run automatically by build or test - you invoke it explicitly and commit the generated files.

What it does

Finds //go:generate lines in the named packages and executes each command (e.g. stringer, mockgen, protoc). It does no dependency analysis and never re-runs on its own; you decide when to run it.

Common usage

go generate ./...                 # run all generators
go generate -run stringer ./...   # only directives matching a regex
go generate -x ./...              # print the commands as they run

Common CI error: generated code is stale

A build uses out-of-date generated files because someone changed the source but did not re-run go generate. Gate it in CI: run go generate ./... then git diff --exit-code, which fails when the committed generated output no longer matches. The generator binaries (stringer, mockgen) must be installed on the runner first.

Options

Related guides