Merge pull request #538 from alixander/restrict-near-constant

restrict near criteria

ci/release/changelogs/next.md

@@ -3,3 +3,5 @@
 #### Improvements 🧹
 
 #### Bugfixes ⛑️
+
+- Restricts where `near` key constant values can be used, with good error messages, instead of erroring (e.g. setting `near: top-center` on a container would cause bad layouts or error). [#538](https://github.com/terrastruct/d2/pull/538)

d2compiler/compile.go

@@ -860,6 +860,23 @@ func (c *compiler) validateNear(g *d2graph.Graph) {
 				c.errorf(obj.Attributes.NearKey.GetRange().Start, obj.Attributes.NearKey.GetRange().End, "constant near keys can only be set on root level shapes")
 				continue
 			}
+			if !isKey && isConst && len(obj.ChildrenArray) > 0 {
+				c.errorf(obj.Attributes.NearKey.GetRange().Start, obj.Attributes.NearKey.GetRange().End, "constant near keys cannot be set on shapes with children")
+				continue
+			}
+			if !isKey && isConst {
+				is := false
+				for _, e := range g.Edges {
+					if e.Src == obj || e.Dst == obj {
+						is = true
+						break
+					}
+				}
+				if is {
+					c.errorf(obj.Attributes.NearKey.GetRange().Start, obj.Attributes.NearKey.GetRange().End, "constant near keys cannot be set on connected shapes")
+					continue
+				}
+			}
 		}
 	}
 }

d2compiler/compile_test.go

@@ -1278,6 +1278,28 @@ x -> y: {
 			text: `x.near: txop-center
 `,
 			expErr: `d2/testdata/d2compiler/TestCompile/near_bad_constant.d2:1:1: 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_bad_container",
+
+			text: `x: {
+  near: top-center
+  y
+}
+`,
+			expErr: `d2/testdata/d2compiler/TestCompile/near_bad_container.d2:1:1: constant near keys cannot be set on shapes with children
+`,
+		},
+		{
+			name: "near_bad_connected",
+
+			text: `x: {
+  near: top-center
+}
+x -> y
+`,
+			expErr: `d2/testdata/d2compiler/TestCompile/near_bad_connected.d2:1:1: constant near keys cannot be set on connected shapes
 `,
 		},
 		{

testdata/d2compiler/TestCompile/near_bad_connected.exp.json

@@ -0,0 +1,12 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/near_bad_connected.d2,0:0:0-0:10:10",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/near_bad_connected.d2:1:1: constant near keys cannot be set on connected shapes"
+      }
+    ]
+  }
+}

testdata/d2compiler/TestCompile/near_bad_container.exp.json

@@ -0,0 +1,12 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/near_bad_container.d2,0:0:0-0:10:10",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/near_bad_container.d2:1:1: constant near keys cannot be set on shapes with children"
+      }
+    ]
+  }
+}