fix null key

d2compiler/compile_test.go

@@ -1650,6 +1650,16 @@ choo: {
 				}
 			},
 		},
+		{
+			name: "null",
+
+			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].IDVal)
+			},
+		},
 	}
 
 	for _, tc := range testCases {

d2format/escape.go

@@ -47,10 +47,6 @@ 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 {

go.mod

@@ -6,6 +6,7 @@ require (
 	cdr.dev/slog v1.4.2-0.20221206192828-e4803b10ae17
 	github.com/PuerkitoBio/goquery v1.8.0
 	github.com/alecthomas/chroma v0.10.0
+	github.com/davecgh/go-spew v1.1.1
 	github.com/dop251/goja v0.0.0-20221118162653-d4bf6fde1b86
 	github.com/fsnotify/fsnotify v1.6.0
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
@@ -28,7 +29,6 @@ require (
 	cloud.google.com/go/compute v1.7.0 // indirect
 	github.com/andybalholm/cascadia v1.3.1 // indirect
 	github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dlclark/regexp2 v1.7.0 // indirect
 	github.com/fatih/color v1.13.0 // indirect
 	github.com/gin-gonic/gin v1.7.7 // indirect

testdata/d2compiler/TestCompile/null.exp.json

@@ -0,0 +1,102 @@
+{
+  "graph": {
+    "ast": {
+      "range": "d2/testdata/d2compiler/TestCompile/null.d2,0:0:0-1:0:5",
+      "nodes": [
+        {
+          "map_key": {
+            "range": "d2/testdata/d2compiler/TestCompile/null.d2,0:0:0-0:4:4",
+            "key": {
+              "range": "d2/testdata/d2compiler/TestCompile/null.d2,0:0:0-0:4:4",
+              "path": [
+                {
+                  "unquoted_string": {
+                    "range": "d2/testdata/d2compiler/TestCompile/null.d2,0:0:0-0:4:4",
+                    "value": [
+                      {
+                        "string": "null",
+                        "raw_string": "null"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "primary": {},
+            "value": {}
+          }
+        }
+      ]
+    },
+    "root": {
+      "id": "",
+      "id_val": "",
+      "label_dimensions": {
+        "width": 0,
+        "height": 0
+      },
+      "attributes": {
+        "label": {
+          "value": ""
+        },
+        "style": {},
+        "near_key": null,
+        "shape": {
+          "value": ""
+        },
+        "direction": {
+          "value": ""
+        }
+      },
+      "zIndex": 0
+    },
+    "edges": null,
+    "objects": [
+      {
+        "id": "null",
+        "id_val": "null",
+        "label_dimensions": {
+          "width": 0,
+          "height": 0
+        },
+        "references": [
+          {
+            "key": {
+              "range": "d2/testdata/d2compiler/TestCompile/null.d2,0:0:0-0:4:4",
+              "path": [
+                {
+                  "unquoted_string": {
+                    "range": "d2/testdata/d2compiler/TestCompile/null.d2,0:0:0-0:4:4",
+                    "value": [
+                      {
+                        "string": "null",
+                        "raw_string": "null"
+                      }
+                    ]
+                  }
+                }
+              ]
+            },
+            "key_path_index": 0,
+            "map_key_edge_index": 0
+          }
+        ],
+        "attributes": {
+          "label": {
+            "value": "null"
+          },
+          "style": {},
+          "near_key": null,
+          "shape": {
+            "value": ""
+          },
+          "direction": {
+            "value": ""
+          }
+        },
+        "zIndex": 0
+      }
+    ]
+  },
+  "err": null
+}