nixd/definition: regression test, for goto-definition on derivation

tools/nixd/test/goto-definition-derivation.md

@@ -0,0 +1,91 @@
+# RUN: nixd --lit-test < %s | FileCheck %s
+
+<-- initialize(0)
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":0,
+   "method":"initialize",
+   "params":{
+      "processId":123,
+      "rootPath":"",
+      "capabilities":{
+      },
+      "trace":"off"
+   }
+}
+```
+
+
+<-- textDocument/didOpen
+
+Testing this nix file, a dummy derivation.
+
+```nix
+let
+  foo = {
+    type = "derivation";
+    meta.position = "/foo.nix:4";
+  };
+in
+foo
+#^ expected location: foo.nix:4
+```
+
+```json
+{
+    "jsonrpc": "2.0",
+    "method": "textDocument/didOpen",
+    "params": {
+        "textDocument": {
+            "uri": "file:///derivation.nix",
+            "languageId": "nix",
+            "version": 1,
+            "text": "let\r\n  foo = {\r\n    type = \"derivation\";\r\n    meta.position = \"\/foo.nix:4\";\r\n  };\r\nin\r\nfoo"
+        }
+    }
+}
+```
+
+<-- textDocument/definition
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":1,
+   "method":"textDocument/definition",
+   "params":{
+      "textDocument":{
+         "uri":"file:///derivation.nix"
+      },
+      "position":{
+         "line":6,
+         "character":0
+      }
+   }
+}
+```
+
+
+```
+     CHECK: "id": 1,
+CHECK-NEXT:   "jsonrpc": "2.0",
+CHECK-NEXT:   "result": {
+CHECK-NEXT:     "range": {
+CHECK-NEXT:       "end": {
+CHECK-NEXT:         "character": 0,
+CHECK-NEXT:         "line": 4
+CHECK-NEXT:       },
+CHECK-NEXT:       "start": {
+CHECK-NEXT:         "character": 0,
+CHECK-NEXT:         "line": 4
+CHECK-NEXT:       }
+CHECK-NEXT:     },
+CHECK-NEXT:     "uri": "file:///foo.nix"
+CHECK-NEXT:   }
+```
+
+```json
+{"jsonrpc":"2.0","method":"exit"}
+```