prevent near to special objects

ci/release/changelogs/next.md

@@ -4,7 +4,8 @@
 
 #### Improvements 🧹
 
-- Boards no longer inherit `label` fields from parents. [#1838](https://github.com/terrastruct/d2/pull/1838)
+- Boards no longer inherit `label` fields from parents [#1838](https://github.com/terrastruct/d2/pull/1838)
+- Prevents `near` targeting a child of a special object like grid cells, which wasn't doing anything [#1851](https://github.com/terrastruct/d2/pull/1851)
 
 #### Bugfixes ⛑️
 

d2compiler/compile.go

@@ -1097,6 +1097,14 @@ func (c *compiler) validateNear(g *d2graph.Graph) {
 						continue
 					}
 				}
+				if nearObj.ClosestGridDiagram() != nil {
+					c.errorf(obj.NearKey, "near keys cannot be set to descendants of special objects, like grid cells")
+					continue
+				}
+				if nearObj.OuterSequenceDiagram() != nil {
+					c.errorf(obj.NearKey, "near keys cannot be set to descendants of special objects, like sequence diagram actors")
+					continue
+				}
 			} else if isConst {
 				if obj.Parent != g.Root {
 					c.errorf(obj.NearKey, "constant near keys can only be set on root level shapes")

d2compiler/compile_test.go

@@ -1607,6 +1607,17 @@ d2/testdata/d2compiler/TestCompile/near-invalid.d2:14:9: near keys cannot be set
 `,
 			expErr: `d2/testdata/d2compiler/TestCompile/near_bad_constant.d2:1:9: near key "txop-center" must be the absolute path to a shape or one of the following constants: top-left, top-center, top-right, center-left, center-right, bottom-left, bottom-center, bottom-right`,
 		},
+		{
+			name: "near_special",
+
+			text: `x.near: z.x
+z: {
+  grid-rows: 1
+  x
+}
+`,
+			expErr: `d2/testdata/d2compiler/TestCompile/near_special.d2:1:9: near keys cannot be set to descendants of special objects, like grid cells`,
+		},
 		{
 			name: "near_bad_connected",