Check committed Go formatting

check.go

@@ -49,6 +49,9 @@ type ReleaseRequest struct {
 // preserves the current validation behavior.
 type ValidationSpec struct {
 	Go GoValidationSpec
+	// GoFormat checks the formatting of committed regular Go source files. It
+	// does not modify repository contents and is disabled when false.
+	GoFormat bool
 }
 
 // GoValidationSpec selects checks performed by the Go toolchain.
@@ -74,7 +77,9 @@ type GoValidationSpec struct {
 // of test-time vet, and Validation.Go.CompileTargets compiles all packages for
 // each selected GOOS/GOARCH pair after tests and vet with cgo disabled. Package
 // compilation produces no artifacts and does not execute target binaries.
-// Their zero values preserve the ordinary suite. If
+// Validation.GoFormat checks regular committed Go source after those selected
+// Go checks and before AdditionalChecks. Its zero value disables formatting.
+// The zero values of all selections preserve the ordinary suite. If
 // Build selects targets, Check builds them after validation in temporary
 // storage outside the worktree, then rechecks
 // branch, HEAD, worktree, index, and local tag state. Success establishes local
@@ -100,6 +105,7 @@ func candidateRequest(request ReleaseRequest) candidate.Request {
 			Race:           request.Validation.Go.Race,
 			FullVet:        request.Validation.Go.FullVet,
 			CompileTargets: make([]validation.Target, len(request.Validation.Go.CompileTargets)),
+			GoFormat:       request.Validation.GoFormat,
 		},
 		AdditionalChecks: candidateChecks(request.AdditionalChecks),
 		AfterValidate:    internalbuild.CandidateCallback(internalBuildSpec(request.Build), request.Output),