From dd1de57200b7b146aaa42e298d60389fc0ee5e0f Mon Sep 17 00:00:00 2001
From: Anmol Sethi <anmol@terrastruct.com>
Date: Mon, 26 Dec 2022 11:18:09 -0800
Subject: [PATCH] d2format: Escape null correctly

---
 d2compiler/compile_test.go                    | 2 +-
 d2format/escape.go                            | 4 ++++
 d2format/escape_test.go                       | 2 +-
 testdata/d2compiler/TestCompile/null.exp.json | 2 +-
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/d2compiler/compile_test.go b/d2compiler/compile_test.go
index 311dd2267..f72894721 100644
--- a/d2compiler/compile_test.go
+++ b/d2compiler/compile_test.go
@@ -1656,7 +1656,7 @@ choo: {
 			text: `null
 `,
 			assertions: func(t *testing.T, g *d2graph.Graph) {
-				tassert.Equal(t, "null", g.Objects[0].ID)
+				tassert.Equal(t, "'null'", g.Objects[0].ID)
 				tassert.Equal(t, "null", g.Objects[0].IDVal)
 			},
 		},
diff --git a/d2format/escape.go b/d2format/escape.go
index 8fad2892c..9789a9c2d 100644
--- a/d2format/escape.go
+++ b/d2format/escape.go
@@ -47,6 +47,10 @@ func escapeUnquotedValue(s string, inKey bool) string {
 		return `""`
 	}
 
+	if strings.EqualFold(s, "null") {
+		return `'null'`
+	}
+
 	var b strings.Builder
 	for i, r := range s {
 		switch r {
diff --git a/d2format/escape_test.go b/d2format/escape_test.go
index c0090c03f..b7e67837c 100644
--- a/d2format/escape_test.go
+++ b/d2format/escape_test.go
@@ -170,7 +170,7 @@ func TestEscapeUnquoted(t *testing.T) {
 		{
 			name: "null",
 			str:  `null`,
-			exp:  `\null`,
+			exp:  `'null'`,
 		},
 		{
 			name: "empty",
diff --git a/testdata/d2compiler/TestCompile/null.exp.json b/testdata/d2compiler/TestCompile/null.exp.json
index 220260a45..f38e28de6 100644
--- a/testdata/d2compiler/TestCompile/null.exp.json
+++ b/testdata/d2compiler/TestCompile/null.exp.json
@@ -53,7 +53,7 @@
     "edges": null,
     "objects": [
       {
-        "id": "null",
+        "id": "'null'",
         "id_val": "null",
         "label_dimensions": {
           "width": 0,