module check refuses an artifact context naming another repository (issue 1019)

cmd/mesh-controller/check.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/link"
 )
 
 // moduleCheck judges manifests where they are written, with no mesh (novox/hq ADR 0037, issue 148).
@@ -114,6 +115,20 @@ func moduleCheckFor(paths []string, longestMachine int, out io.Writer) error {
 			failed += len(wrong)
 			faulted[m.Module] = true
 		}
+		// A module lives whole in one repository (novox/hq ADR 0420 §1, issue 1019): when the check is told the
+		// repository it runs for (MESH_CHECK_REPOSITORY, set by the build's check), an artifact building from
+		// another is refused, as the merge gate refuses it. A run by hand names no repository and judges none.
+		if repo := os.Getenv("MESH_CHECK_REPOSITORY"); repo != "" && m.Build != nil {
+			for _, a := range m.Build.Artifacts {
+				if a.Context != nil && a.Context.Repository != "" && !sameRepository(a.Context.Repository,
+					link.SourceMoved{Owner: ownerOf(repo), Repo: repoOf(repo)}) {
+					fmt.Fprintf(out, "%s: %s builds artifact %s from %s: a module lives whole in one repository "+
+						"(novox/hq ADR 0420 §1)\n", path, m.Module, a.Name, a.Context.Repository)
+					failed++
+					faulted[m.Module] = true
+				}
+			}
+		}
 		if named := catalogue.InstallationProblems(m); len(named) > 0 {
 			for _, p := range named {
 				fmt.Fprintf(out, "%s: %s\n", path, p)