Implement tests to improve coverage:

* asts should be hashable/copyable/reprable.
* lexer tokens, loc and source locations should be able to be repr.
* visitors should properly inherit their enter/leave methods from parents.

Author: jhgg

graphql/core/language/source.py

@@ -9,6 +9,10 @@ def __init__(self, body, name='GraphQL'):
         self.name = name
 
     def __eq__(self, other):
-        if isinstance(other, Source):
-            return self.body == other.body and self.name == other.name
-        return False
+        return (
+            self is other or (
+                isinstance(other, Source) and
+                self.body == other.body and
+                self.name == other.name
+            )
+        )

graphql/core/language/visitor_meta.py

@@ -53,6 +53,7 @@ def __new__(cls, name, bases, attrs):
         for base in bases:
             if hasattr(base, '_enter_handlers'):
                 enter_handlers.update(base._enter_handlers)
+
             if hasattr(base, '_leave_handlers'):
                 leave_handlers.update(base._leave_handlers)
 
@@ -67,6 +68,8 @@ def __new__(cls, name, bases, attrs):
                 ast_type = AST_KIND_TO_TYPE.get(ast_kind)
                 leave_handlers[ast_type] = val
 
+        attrs['_enter_handlers'] = enter_handlers
+        attrs['_leave_handlers'] = leave_handlers
         attrs['_get_enter_handler'] = enter_handlers.get
         attrs['_get_leave_handler'] = leave_handlers.get
         return super(VisitorMeta, cls).__new__(cls, name, bases, attrs)

graphql/core/pyutils/defer.py

@@ -243,8 +243,8 @@ def add_callbacks(self, callback, errback=None,
         >>> deferred.result
         'Got: catched'
         """
-        assert isinstance(callback, collections.Callable)
-        assert errback is None or isinstance(errback, collections.Callable)
+        assert callback is _passthrough or isinstance(callback, collections.Callable)
+        assert errback is None or errback is _passthrough or isinstance(errback, collections.Callable)
         if errback is None:
             errback = _passthrough
         self.callbacks.append(((callback,
@@ -449,8 +449,7 @@ def defer(func, *args, **kwargs):
     return deferred
 
 
-def _passthrough(arg):
-    return arg
+_passthrough = object()
 
 
 def succeed(result):

tests/core_language/test_ast.py

@@ -0,0 +1,20 @@
+import copy
+from graphql.core.language.visitor_meta import VisitorMeta, QUERY_DOCUMENT_KEYS
+
+
+def test_ast_is_hashable():
+    for node_class in QUERY_DOCUMENT_KEYS:
+        node = node_class(loc=None, **{k: k for k in node_class._fields})
+        assert hash(node)
+
+
+def test_ast_is_copyable():
+    for node_class in QUERY_DOCUMENT_KEYS:
+        node = node_class(loc=None, **{k: k for k in node_class._fields})
+        assert copy.copy(node) == node
+
+
+def test_ast_is_reprable():
+    for node_class in QUERY_DOCUMENT_KEYS:
+        node = node_class(loc=None, **{k: k for k in node_class._fields})
+        assert repr(node)

tests/core_language/test_lexer.py

@@ -8,6 +8,11 @@ def lex_one(s):
     return Lexer(Source(s)).next_token()
 
 
+def test_repr_token():
+    token = lex_one('500')
+    assert repr(token) == "<Token kind=Int at 0..3 value='500'>"
+
+
 def test_disallows_uncommon_control_characters():
     with raises(LanguageError) as excinfo:
         lex_one(u'\u0007')
@@ -213,4 +218,3 @@ def test_lex_reports_useful_information_for_dashes_in_names():
         lexer.next_token()
 
     assert u'Syntax Error GraphQL (1:3) Invalid number, expected digit but got: "b".' in excinfo.value.message
-

tests/core_language/test_location.py

@@ -0,0 +1,6 @@
+from graphql.core.language.location import SourceLocation
+
+
+def test_repr_source_location():
+    loc = SourceLocation(10, 25)
+    assert repr(loc) == '<SourceLocation line=10 column=25>'

tests/core_language/test_parser.py

@@ -7,6 +7,11 @@
 from .fixtures import KITCHEN_SINK
 
 
+def test_repr_loc():
+    loc = Loc(start=10, end=25, source='foo')
+    assert repr(loc) == '<Loc start=10 end=25 source=foo>'
+
+
 def test_parse_provides_useful_errors():
     with raises(LanguageError) as excinfo:
         parse("""{""")

tests/core_language/test_visitor_meta.py

@@ -0,0 +1,38 @@
+from graphql.core.language import ast
+from graphql.core.language.visitor import Visitor
+
+
+def test_visitor_meta_creates_enter_and_leave_handlers():
+    class MyVisitor(Visitor):
+        def enter_OperationDefinition(self):
+            pass
+
+        def leave_OperationDefinition(self):
+            pass
+
+    assert MyVisitor._get_enter_handler(ast.OperationDefinition)
+    assert MyVisitor._get_leave_handler(ast.OperationDefinition)
+
+
+def test_visitor_inherits_parent_definitions():
+    class MyVisitor(Visitor):
+        def enter_OperationDefinition(self):
+            pass
+
+        def leave_OperationDefinition(self):
+            pass
+
+    assert MyVisitor._get_enter_handler(ast.OperationDefinition)
+    assert MyVisitor._get_leave_handler(ast.OperationDefinition)
+
+    class MyVisitorSubclassed(MyVisitor):
+        def enter_FragmentDefinition(self):
+            pass
+
+        def leave_FragmentDefinition(self):
+            pass
+
+    assert MyVisitorSubclassed._get_enter_handler(ast.OperationDefinition)
+    assert MyVisitorSubclassed._get_leave_handler(ast.OperationDefinition)
+    assert MyVisitorSubclassed._get_enter_handler(ast.FragmentDefinition)
+    assert MyVisitorSubclassed._get_leave_handler(ast.FragmentDefinition)