Added GoTo Implementation test

Author: gnikit

test/test_server_implementation.py

@@ -0,0 +1,41 @@
+# from types import NoneType
+from setup_tests import (
+    path_to_uri,
+    run_request,
+    test_dir,
+    write_rpc_request,
+)
+from fortls.json_templates import uri_json
+
+
+def imp_request(file, line, char):
+    return write_rpc_request(
+        1,
+        "textDocument/implementation",
+        {
+            "textDocument": {"uri": path_to_uri(str(file))},
+            "position": {"line": line, "character": char},
+        },
+    )
+
+
+def check_imp_request(response: dict, references: dict):
+    for uri, changes in response.items():
+        refs = references[uri]
+        # Loop over all the changes in the current URI, instances of object
+        for c, r in zip(changes, refs):
+            assert c["range"] == r["range"]
+
+
+def create(file, line, schar, echar):
+    return uri_json(path_to_uri(str(file)), line, schar, line, echar)
+
+
+def test_implementation_type_bound():
+    """Go to implementation of type-bound procedures"""
+    string = write_rpc_request(1, "initialize", {"rootPath": str(test_dir)})
+    file_path = test_dir / "test.f90"
+    string += imp_request(file_path, 3, 17)
+    errcode, results = run_request(string, ["-n", "1"])
+    assert errcode == 0
+    assert results[1] == create(test_dir / "subdir" / "test_free.f90", 49, 11, 28)