fix: graph support for default transformers (#877)

* fix: graph support for default transformers
* fix: add named returnparameters
* fix: single entry point from start
* fix: add source vertex id to graph

Signed-off-by: Mehant Kammakomati <kmehant@gmail.com>

transformer/transformer.go

@@ -409,6 +409,7 @@ func Transform(planArtifacts []plantypes.PlanArtifact, sourceDir, outputPath str
 	var allArtifacts []transformertypes.Artifact
 	newArtifactsToProcess := []transformertypes.Artifact{}
 	pathMappings := []transformertypes.PathMapping{}
+	defaultNewArtifactsToProcess := []transformertypes.Artifact{}
 	iteration := 1
 	// transform default transformers
 	graph := graphtypes.NewGraph()
@@ -419,7 +420,7 @@ func Transform(planArtifacts []plantypes.PlanArtifact, sourceDir, outputPath str
 		if err != nil {
 			logrus.Errorf("failed to transform using the transformer %s. Error: %q", tDefaultConfig.Name, err)
 		}
-		newArtifactsToProcess = append(newArtifactsToProcess, defaultArtifacts...)
+		defaultNewArtifactsToProcess = append(defaultNewArtifactsToProcess, defaultArtifacts...)
 		pathMappings = append(pathMappings, newPathMappings...)
 	}
 	logrus.Infof("Iteration %d", iteration)
@@ -442,10 +443,11 @@ func Transform(planArtifacts []plantypes.PlanArtifact, sourceDir, outputPath str
 	}
 
 	// logging
-	allArtifacts = newArtifactsToProcess
 	for _, artifact := range newArtifactsToProcess {
 		artifact.Configs[graphtypes.GraphSourceVertexKey] = startVertexId
 	}
+	newArtifactsToProcess = append(newArtifactsToProcess, defaultNewArtifactsToProcess...)
+	allArtifacts = newArtifactsToProcess
 	// logging
 
 	for {
@@ -558,16 +560,15 @@ func transform(newArtifactsToProcess, allArtifacts []transformertypes.Artifact,
 	return pathMappings, newArtifactsCreated, nil
 }
 
-func runSingleTransform(artifactsToProcess, allArtifacts []transformertypes.Artifact, transformer Transformer, tconfig transformertypes.Transformer, env *environment.Environment, graph *graphtypes.Graph, iteration int) ([]transformertypes.PathMapping, []transformertypes.Artifact, error) {
+func runSingleTransform(artifactsToProcess, allArtifacts []transformertypes.Artifact, transformer Transformer, tconfig transformertypes.Transformer, env *environment.Environment, graph *graphtypes.Graph, iteration int) (newPathMappings []transformertypes.PathMapping, newArtifacts []transformertypes.Artifact, err error) {
 	if err := env.Reset(); err != nil {
 		return nil, nil, fmt.Errorf("failed to reset the environment: %+v Error: %q", env, err)
 	}
 
-	newPathMappings, newArtifacts, err := transformer.Transform(
+	newPathMappings, newArtifacts, err = transformer.Transform(
 		*env.Encode(&artifactsToProcess).(*[]transformertypes.Artifact),
 		*env.Encode(&allArtifacts).(*[]transformertypes.Artifact),
 	)
-
 	// logging
 	{
 		vertexName := fmt.Sprintf("iteration: %d\nclass: %s\nname: %s", iteration, tconfig.Spec.Class, tconfig.Name)
@@ -580,6 +581,11 @@ func runSingleTransform(artifactsToProcess, allArtifacts []transformertypes.Arti
 				"pathMappings":      summarizePathMappings(newPathMappings),
 			},
 		)
+		// transformers that are invoked by default has source vertex as start
+		if tconfig.Spec.InvokedByDefault.Enabled {
+			edgeName := fmt.Sprintf("%d -> %d (invoked by default)", 0, targetVertexId)
+			graph.AddEdge(graph.SourceVertexId, targetVertexId, edgeName, nil)
+		}
 		for _, artifact := range artifactsToProcess {
 			sourceVertexId, ok := artifact.Configs[graphtypes.GraphSourceVertexKey].(int)
 			if !ok {

types/graph/graph.go

@@ -18,11 +18,12 @@ package graph
 
 // Graph contains transformers and artifacts being passed between them.
 type Graph struct {
-	vertexId int
-	edgeId   int
-	Version  string         `json:"version"`
-	Vertices map[int]Vertex `json:"vertices,omitempty"`
-	Edges    map[int]Edge   `json:"edges,omitempty"`
+	SourceVertexId int
+	vertexId       int
+	edgeId         int
+	Version        string         `json:"version"`
+	Vertices       map[int]Vertex `json:"vertices,omitempty"`
+	Edges          map[int]Edge   `json:"edges,omitempty"`
 }
 
 // Vertex is a single transformer.
@@ -100,18 +101,22 @@ const (
 // NewGraph creates a new graph.
 func NewGraph() *Graph {
 	return &Graph{
-		vertexId: -1,
-		edgeId:   -1,
-		Version:  GraphFileVersion,
-		Vertices: map[int]Vertex{},
-		Edges:    map[int]Edge{},
+		SourceVertexId: -1,
+		vertexId:       -1,
+		edgeId:         -1,
+		Version:        GraphFileVersion,
+		Vertices:       map[int]Vertex{},
+		Edges:          map[int]Edge{},
 	}
 }
 
 // AddVertex adds a new vertex to the graph.
 func (g *Graph) AddVertex(name string, iteration int, data map[string]interface{}) int {
 	g.vertexId++
 	g.Vertices[g.vertexId] = Vertex{Id: g.vertexId, Iteration: iteration, Name: name, Data: data}
+	if g.SourceVertexId == -1 {
+		g.SourceVertexId = g.vertexId
+	}
 	return g.vertexId
 }