Marker name is a string, not a lexer token (#286)

* Marker name is a string, not a lexer token

* add unit test

Author: dimbleby

src/poetry/core/version/markers.py

@@ -742,7 +742,9 @@ def _compact_markers(tree_elements: "Tree", tree_prefix: str = "") -> MarkerType
                 )
 
             value = value[1:-1]
-            groups[-1] = MultiMarker.of(groups[-1], SingleMarker(name, f"{op}{value}"))
+            groups[-1] = MultiMarker.of(
+                groups[-1], SingleMarker(str(name), f"{op}{value}")
+            )
         elif token.data == f"{tree_prefix}BOOL_OP" and token.children[0] == "or":
             groups.append(MultiMarker())
 

tests/packages/test_dependency.py

@@ -298,3 +298,10 @@ def test_marker_properly_sets_python_constraint():
     dependency.marker = 'python_version >= "3.6" and python_version < "4.0"'
 
     assert str(dependency.python_constraint) == ">=3.6,<4.0"
+
+
+def test_dependency_markers_are_the_same_as_markers():
+    dependency = Dependency.create_from_pep_508('foo ; extra=="bar"')
+    marker = parse_marker('extra=="bar"')
+
+    assert dependency.marker == marker