d2ir: allow absolute imports

ci/release/changelogs/next.md

@@ -5,6 +5,7 @@
   scope (e.g. to a sibling board at the scope its imported to) [#2075](https://github.com/terrastruct/d2/pull/2075)
 - Autoformat: Reserved keywords are formatted to be lowercase [#2098](https://github.com/terrastruct/d2/pull/2098)
 - Misc: characters in the unicode range for Latin-1 and geometric shapes are measured more accurately [#2100](https://github.com/terrastruct/d2/pull/2100)
+- Imports: can now import from absolute file paths [#2113](https://github.com/terrastruct/d2/pull/2113)
 
 #### Improvements 🧹
 

d2ir/import.go

@@ -17,17 +17,13 @@ func (c *compiler) pushImportStack(imp *d2ast.Import) (string, bool) {
 		return "", false
 	}
 	if len(c.importStack) > 0 {
-		if path.IsAbs(impPath) {
-			c.errorf(imp, "import paths must be relative")
-			return "", false
-		}
-
 		if path.Ext(impPath) != ".d2" {
 			impPath += ".d2"
 		}
 
-		// Imports are always relative to the importing file.
-		impPath = path.Join(path.Dir(c.importStack[len(c.importStack)-1]), impPath)
+		if !path.IsAbs(impPath) {
+			impPath = path.Join(path.Dir(c.importStack[len(c.importStack)-1]), impPath)
+		}
 	}
 
 	for i, p := range c.importStack {

d2ir/import_test.go

@@ -252,15 +252,6 @@ label: meow`,
 					assert.ErrorString(t, err, `index.d2:1:1: failed to import "../x.d2": open ../x.d2: invalid argument`)
 				},
 			},
-			{
-				name: "absolute",
-				run: func(t testing.TB) {
-					_, err := compileFS(t, "index.d2", map[string]string{
-						"index.d2": "...@/x.d2",
-					})
-					assert.ErrorString(t, err, `index.d2:1:1: import paths must be relative`)
-				},
-			},
 			{
 				name: "parse",
 				run: func(t testing.TB) {