Infer artifact dependencies from configured inputs

internal/config/validate_scriptorium.go

@@ -108,10 +108,9 @@ func validateScriptoriumDependenciesAndInputs(
 	referencedArtifacts := make(map[string]struct{})
 	for _, artifactName := range artifactNames {
 		artifactCfg := artifacts[artifactName]
-		depSet := make(map[string]struct{}, len(artifactCfg.DependsOn))
-		for i, depName := range artifactCfg.DependsOn {
+		for _, depName := range artifactCfg.DependsOn {
 			trimmedDep := strings.TrimSpace(depName)
-			field := fmt.Sprintf("pipeline.scriptorium.artifacts.%s.depends_on[%d]", artifactName, i)
+			field := dependencyOriginField(artifactName, trimmedDep, artifactCfg)
 			if trimmedDep == "" {
 				return nil, fmt.Errorf("%s must be non-empty", field)
 			}
@@ -119,9 +118,8 @@ func validateScriptoriumDependenciesAndInputs(
 				return nil, fmt.Errorf("%s %q is not a configured artifact key", field, depName)
 			}
 			if trimmedDep == artifactName {
-				return nil, fmt.Errorf("pipeline.scriptorium.artifacts.%s.depends_on must not include itself", artifactName)
+				return nil, fmt.Errorf("%s must not include itself", field)
 			}
-			depSet[trimmedDep] = struct{}{}
 			referencedArtifacts[trimmedDep] = struct{}{}
 		}
 
@@ -146,15 +144,6 @@ func validateScriptoriumDependenciesAndInputs(
 				return nil, err
 			}
 			if referencedArtifact != "" {
-				if _, ok := depSet[referencedArtifact]; !ok {
-					return nil, fmt.Errorf(
-						"pipeline.scriptorium.artifacts.%s.inputs.%s.source %q requires depends_on entry %q",
-						artifactName,
-						inputName,
-						source,
-						referencedArtifact,
-					)
-				}
 				referencedArtifacts[referencedArtifact] = struct{}{}
 			}
 		}
@@ -281,13 +270,17 @@ func ValidateScriptoriumArtifactDependencies(artifacts map[string]ScriptoriumArt
 		for _, dep := range cfg.DependsOn {
 			trimmedDep := strings.TrimSpace(dep)
 			if trimmedDep == "" {
-				return fmt.Errorf("pipeline.scriptorium.artifacts.%s.depends_on entries must be non-empty", name)
+				field := dependencyOriginField(name, trimmedDep, cfg)
+				if field == fmt.Sprintf("pipeline.scriptorium.artifacts.%s.depends_on", name) {
+					return fmt.Errorf("%s entries must be non-empty", field)
+				}
+				return fmt.Errorf("%s must be non-empty", field)
 			}
 			if _, ok := artifacts[trimmedDep]; !ok {
-				return fmt.Errorf("pipeline.scriptorium.artifacts.%s dependency %q is not configured", name, dep)
+				return fmt.Errorf("%s dependency %q is not configured", dependencyOriginField(name, trimmedDep, cfg), dep)
 			}
 			if trimmedDep == name {
-				return fmt.Errorf("pipeline.scriptorium.artifacts.%s.depends_on must not include itself", name)
+				return fmt.Errorf("%s must not include itself", dependencyOriginField(name, trimmedDep, cfg))
 			}
 			if _, duplicate := seen[trimmedDep]; duplicate {
 				continue
@@ -303,14 +296,17 @@ func ValidateScriptoriumArtifactDependencies(artifacts map[string]ScriptoriumArt
 
 	var visit func(node string) error
 	visit = func(node string) error {
-		if visiting[node] {
-			return fmt.Errorf("pipeline.scriptorium.artifacts dependencies must not contain cycles")
-		}
 		if visited[node] {
 			return nil
 		}
 		visiting[node] = true
 		for _, dep := range graph[node] {
+			if visiting[dep] {
+				return fmt.Errorf(
+					"%s creates a cycle; pipeline.scriptorium.artifacts dependencies must not contain cycles",
+					dependencyOriginField(node, dep, artifacts[node]),
+				)
+			}
 			if err := visit(dep); err != nil {
 				return err
 			}