From 31564f148769f753a6d95e750bb104825c015b57 Mon Sep 17 00:00:00 2001
From: Alexander Wang <alex@terrastruct.com>
Date: Mon, 26 Dec 2022 20:51:37 -0800
Subject: [PATCH 1/2] exercise serde

---
 d2layouts/d2sequence/layout.go | 31 ++++++++++++++++++++-----------
 e2etests/e2e_test.go           | 26 ++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/d2layouts/d2sequence/layout.go b/d2layouts/d2sequence/layout.go
index 1747c859b..49ae00b43 100644
--- a/d2layouts/d2sequence/layout.go
+++ b/d2layouts/d2sequence/layout.go
@@ -12,16 +12,7 @@ import (
 	"oss.terrastruct.com/util-go/go2"
 )
 
-// Layout runs the sequence diagram layout engine on objects of shape sequence_diagram
-//
-// 1. Traverse graph from root, skip objects with shape not `sequence_diagram`
-// 2. Construct a sequence diagram from all descendant objects and edges
-// 3. Remove those objects and edges from the main graph
-// 4. Run layout on sequence diagrams
-// 5. Set the resulting dimensions to the main graph shape
-// 6. Run core layouts (still without sequence diagram innards)
-// 7. Put back sequence diagram innards in correct location
-func Layout(ctx context.Context, g *d2graph.Graph, layout func(ctx context.Context, g *d2graph.Graph) error) error {
+func WithoutSequenceDiagrams(ctx context.Context, g *d2graph.Graph) (map[string]*sequenceDiagram, map[string]int, map[string]int, error) {
 	objectsToRemove := make(map[*d2graph.Object]struct{})
 	edgesToRemove := make(map[*d2graph.Edge]struct{})
 	sequenceDiagrams := make(map[string]*sequenceDiagram)
@@ -41,7 +32,7 @@ func Layout(ctx context.Context, g *d2graph.Graph, layout func(ctx context.Conte
 
 		sd, err := layoutSequenceDiagram(g, obj)
 		if err != nil {
-			return err
+			return nil, nil, nil, err
 		}
 		obj.Children = make(map[string]*d2graph.Object)
 		obj.ChildrenArray = nil
@@ -72,6 +63,24 @@ func Layout(ctx context.Context, g *d2graph.Graph, layout func(ctx context.Conte
 	// TODO this isn't a proper deletion because the objects still appear as children of the object
 	g.Objects = layoutObjects
 
+	return sequenceDiagrams, objectOrder, edgeOrder, nil
+}
+
+// Layout runs the sequence diagram layout engine on objects of shape sequence_diagram
+//
+// 1. Traverse graph from root, skip objects with shape not `sequence_diagram`
+// 2. Construct a sequence diagram from all descendant objects and edges
+// 3. Remove those objects and edges from the main graph
+// 4. Run layout on sequence diagrams
+// 5. Set the resulting dimensions to the main graph shape
+// 6. Run core layouts (still without sequence diagram innards)
+// 7. Put back sequence diagram innards in correct location
+func Layout(ctx context.Context, g *d2graph.Graph, layout func(ctx context.Context, g *d2graph.Graph) error) error {
+	sequenceDiagrams, objectOrder, edgeOrder, err := WithoutSequenceDiagrams(ctx, g)
+	if err != nil {
+		return err
+	}
+
 	if g.Root.IsSequenceDiagram() {
 		// the sequence diagram is the only layout engine if the whole diagram is
 		// shape: sequence_diagram
diff --git a/e2etests/e2e_test.go b/e2etests/e2e_test.go
index ec6a2e2cc..ccf4fec8d 100644
--- a/e2etests/e2e_test.go
+++ b/e2etests/e2e_test.go
@@ -17,9 +17,12 @@ import (
 	"oss.terrastruct.com/util-go/assert"
 	"oss.terrastruct.com/util-go/diff"
 
+	"oss.terrastruct.com/d2/d2compiler"
 	"oss.terrastruct.com/d2/d2graph"
 	"oss.terrastruct.com/d2/d2layouts/d2dagrelayout"
 	"oss.terrastruct.com/d2/d2layouts/d2elklayout"
+	"oss.terrastruct.com/d2/d2layouts/d2near"
+	"oss.terrastruct.com/d2/d2layouts/d2sequence"
 	"oss.terrastruct.com/d2/d2lib"
 	"oss.terrastruct.com/d2/d2renderers/d2svg"
 	"oss.terrastruct.com/d2/d2target"
@@ -88,6 +91,27 @@ func runa(t *testing.T, tcs []testCase) {
 	}
 }
 
+// serde exercises serializing and deserializing the graph
+func serde(t *testing.T, tc testCase, ruler *textmeasure.Ruler) {
+	ctx := context.Background()
+	ctx = log.WithTB(ctx, t, nil)
+	g, err := d2compiler.Compile("", strings.NewReader(tc.script), &d2compiler.CompileOptions{
+		UTF16: false,
+	})
+	tassert.Nil(t, err)
+	if len(g.Objects) > 0 {
+		err = g.SetDimensions(nil, ruler, nil)
+		tassert.Nil(t, err)
+		d2near.WithoutConstantNears(ctx, g)
+		d2sequence.WithoutSequenceDiagrams(ctx, g)
+	}
+	b, err := d2graph.SerializeGraph(g)
+	tassert.Nil(t, err)
+	var newG d2graph.Graph
+	err = d2graph.DeserializeGraph(b, &newG)
+	tassert.Nil(t, err)
+}
+
 func run(t *testing.T, tc testCase) {
 	ctx := context.Background()
 	ctx = log.WithTB(ctx, t, nil)
@@ -98,6 +122,8 @@ func run(t *testing.T, tc testCase) {
 		return
 	}
 
+	serde(t, tc, ruler)
+
 	layoutsTested := []string{"dagre", "elk"}
 
 	for _, layoutName := range layoutsTested {

From 45797eb8599350e641f83cb8d66ec1849f62cf94 Mon Sep 17 00:00:00 2001
From: Alexander Wang <alex@terrastruct.com>
Date: Mon, 26 Dec 2022 20:52:47 -0800
Subject: [PATCH 2/2] comment

---
 e2etests/e2e_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/e2etests/e2e_test.go b/e2etests/e2e_test.go
index ccf4fec8d..994770426 100644
--- a/e2etests/e2e_test.go
+++ b/e2etests/e2e_test.go
@@ -92,6 +92,7 @@ func runa(t *testing.T, tcs []testCase) {
 }
 
 // serde exercises serializing and deserializing the graph
+// We want to run all the steps leading up to serialization in the course of regular layout
 func serde(t *testing.T, tc testCase, ruler *textmeasure.Ruler) {
 	ctx := context.Background()
 	ctx = log.WithTB(ctx, t, nil)