validate edges

d2compiler/compile.go

@@ -73,6 +73,7 @@ func (c *compiler) compileBoard(g *d2graph.Graph, ir *d2ir.Map) *d2graph.Graph {
 		c.validateKeys(g.Root, ir)
 	}
 	c.validateNear(g)
+	c.validateEdges(g)
 
 	c.compileBoardsField(g, ir, "layers")
 	c.compileBoardsField(g, ir, "scenarios")
@@ -787,6 +788,19 @@ func (c *compiler) validateNear(g *d2graph.Graph) {
 	}
 }
 
+func (c *compiler) validateEdges(g *d2graph.Graph) {
+	for _, edge := range g.Edges {
+		if grid := edge.Src.ClosestGrid(); grid != nil {
+			c.errorf(edge.GetAstEdge(), "edge %#v cannot enter grid %#v", d2format.Format(edge.GetAstEdge()), grid.AbsID())
+			continue
+		}
+		if grid := edge.Dst.ClosestGrid(); grid != nil {
+			c.errorf(edge.GetAstEdge(), "edge %#v cannot enter grid %#v", d2format.Format(edge.GetAstEdge()), grid.AbsID())
+			continue
+		}
+	}
+}
+
 func (c *compiler) validateBoardLinks(g *d2graph.Graph) {
 	for _, obj := range g.Objects {
 		if obj.Attributes.Link == nil {

d2compiler/compile_test.go

@@ -2288,6 +2288,21 @@ obj {
 `,
 			expErr: `d2/testdata/d2compiler/TestCompile/grid_negative.d2:3:11: columns must be a positive integer: "-200"`,
 		},
+		{
+			name: "grid_edge",
+			text: `hey: {
+	rows: 1
+	a -> b
+}
+	c -> hey.b
+	hey.a -> c
+
+	hey -> c: ok
+`,
+			expErr: `d2/testdata/d2compiler/TestCompile/grid_edge.d2:3:2: edge "a -> b" cannot enter grid "hey"
+d2/testdata/d2compiler/TestCompile/grid_edge.d2:5:2: edge "c -> hey.b" cannot enter grid "hey"
+d2/testdata/d2compiler/TestCompile/grid_edge.d2:6:2: edge "hey.a -> c" cannot enter grid "hey"`,
+		},
 	}
 
 	for _, tc := range testCases {

d2graph/d2graph.go

@@ -1013,6 +1013,10 @@ type EdgeReference struct {
 	ScopeObj        *Object    `json:"-"`
 }
 
+func (e *Edge) GetAstEdge() *d2ast.Edge {
+	return e.References[0].Edge
+}
+
 func (e *Edge) GetStroke(dashGapSize interface{}) string {
 	if dashGapSize != 0.0 {
 		return color.B2

d2graph/grid.go

@@ -4,3 +4,13 @@ func (obj *Object) IsGrid() bool {
 	return obj != nil && obj.Attributes != nil &&
 		(obj.Attributes.Rows != nil || obj.Attributes.Columns != nil)
 }
+
+func (obj *Object) ClosestGrid() *Object {
+	if obj.Parent == nil {
+		return nil
+	}
+	if obj.Parent.IsGrid() {
+		return obj.Parent
+	}
+	return obj.Parent.ClosestGrid()
+}

testdata/d2compiler/TestCompile/grid_edge.exp.json

@@ -0,0 +1,20 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/grid_edge.d2,2:1:17-2:7:23",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/grid_edge.d2:3:2: edge \"a -> b\" cannot enter grid \"hey\""
+      },
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/grid_edge.d2,4:1:27-4:11:37",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/grid_edge.d2:5:2: edge \"c -> hey.b\" cannot enter grid \"hey\""
+      },
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/grid_edge.d2,5:1:39-5:11:49",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/grid_edge.d2:6:2: edge \"hey.a -> c\" cannot enter grid \"hey\""
+      }
+    ]
+  }
+}