updates

Author: zeedann

shopify_python/google_styleguide.py

@@ -83,7 +83,7 @@ class GoogleStyleGuideChecker(checkers.BaseChecker):
                   "For example: x = 1 if cond else 2. "
                   "Conditional Expressions okay to use for one-liners. "
                   "In other cases prefer to use a complete if statement. "),
-        'C6014': ('Prefer operator module function %(op)s to lambda function %(lamfun)s',
+        'C6014': ('Prefer operator module function %(op)s to lambda function %(lambda_fcn)s',
                   'lambda-func',
                   "For common operations like multiplication, use the functions from the operator module"
                   "instead of lambda functions. For example, prefer operator.mul to lambda x, y: x * y."),
@@ -112,6 +112,28 @@ class GoogleStyleGuideChecker(checkers.BaseChecker):
             'help': 'Number of AST nodes permitted in a lambda'}),
     )
 
+    UNARY_OPERATORS = {
+        "~": "invert",
+        "-": "neg",
+        "not": "not_",
+        "+": "pos"
+    }
+
+    BINARY_OPERATORS = {
+        "+": "add",
+        "-": "sub",
+        "*": "mul",
+        "/": "truediv",
+        "**": "pow",
+        "%": "modulo",
+        "<": "lt",
+        "<=": "le",
+        "==": "eq",
+        "!=": "ne",
+        ">=": "ge",
+        ">": "gt"
+    }
+
     def visit_assign(self, node):  # type: (astroid.Assign) -> None
         self.__avoid_global_variables(node)
 
@@ -264,42 +286,22 @@ def __lambda_func(self, node):  # type: (astroid.Lambda) -> None
 
         if isinstance(node.body, astroid.UnaryOp):
             if shopify_python.ast.count_tree_size(node.body) == 2 and len(node.args.args) == 1:
-                unary_operators = {
-                    "~": "invert",
-                    "-": "neg",
-                    "not": "not_",
-                    "+": "pos"
-                }
-                preferred_operator_function = unary_operators.get(node.body.op)
+                preferred_operator_function = self.UNARY_OPERATORS.get(node.body.op)
                 name_match = node.args.args[0].name is node.body.operand.name
                 if preferred_operator_function and not isinstance(node.body.operand, astroid.BinOp) and name_match:
                     varname = node.body.operand.name
-                    lamfun = "lambda " + varname + ": " + node.body.op + " " + varname
+                    lambda_fcn = "lambda " + varname + ": " + node.body.op + " " + varname
                     opfun = "operator." + preferred_operator_function
-                    self.add_message('lambda-func', node=node, args={'op': opfun, 'lamfun': lamfun})
+                    self.add_message('lambda-func', node=node, args={'op': opfun, 'lambda_fcn': lambda_fcn})
         elif isinstance(node.body, astroid.BinOp):
             if shopify_python.ast.count_tree_size(node.body) == 3 and len(node.args.args) == 2:
                 left_arg = node.args.args[0].name
                 right_arg = node.args.args[1].name
                 node = node.body
-                binary_operators = {
-                    "+": "add",
-                    "-": "sub",
-                    "*": "mul",
-                    "/": "truediv",
-                    "**": "pow",
-                    "%": "modulo",
-                    "<": "lt",
-                    "<=": "le",
-                    "==": "eq",
-                    "!=": "ne",
-                    ">=": "ge",
-                    ">": "gt"
-                }
-                preferred_operator_function = binary_operators.get(node.op)
+                preferred_operator_function = self.BINARY_OPERATORS.get(node.op)
                 if preferred_operator_function and left_arg is node.left.name and right_arg is node.right.name:
                     left = str(node.left.value) if node.left.name == 'int' else node.left.name
                     right = str(node.right.value) if node.right.name == 'int' else node.right.name
-                    lamfun = "lambda " + left + ', ' + right + ": " + " ".join([left, node.op, right])
+                    lambda_fcn = "lambda " + left + ', ' + right + ": " + " ".join([left, node.op, right])
                     opfun = "operator." + preferred_operator_function
-                    self.add_message('lambda-func', node=node, args={'op': opfun, 'lamfun': lamfun})
+                    self.add_message('lambda-func', node=node, args={'op': opfun, 'lambda_fcn': lambda_fcn})

tests/shopify_python/test_google_styleguide.py

@@ -230,52 +230,30 @@ def test_unary_lambda_func(self):
         unary_root = astroid.builder.parse("""
         def unaryfnc():
             unary_pass = map(lambda x: not (x+3), [1, 2, 3, 4])
-            unary_msg = map(lambda x: -x, [1, 2, 3, 4])
+            unary_fail = map(lambda x: -x, [1, 2, 3, 4])
         """)
 
-        # Unary Op Test 1: This will not trigger a message
-        ulam_pass = unary_root.body[0].body[0].value.args[0]
-        with self.assertNoMessages():
-            self.walk(ulam_pass)
-
-        # Unary Op Test 2: This will trigger a message
         ulam_msg = unary_root.body[0].body[1].value.args[0]
         unary_message = pylint.testutils.Message('lambda-func', node=ulam_msg, args={
             'op': 'operator.neg',
-            'lamfun': 'lambda x: - x'
+            'lambda_fcn': 'lambda x: - x'
             })
         with self.assertAddsMessages(unary_message):
-            self.walk(ulam_msg)
+            self.walk(unary_root)
 
     def test_binary_lambda_func(self):
         binary_root = astroid.builder.parse("""
         def binaryfnc():
             binary_pass = reduce(lambda x, y, z: x * y + z, [1, 2, 3])
             binary_pass2 = map(lambda x: x + 3, [1, 2, 3, 4])
             binary_pass3 = map(lambda x, y: x + 1)
-            binary_msg = reduce(lambda x, y: x * y, [1, 2, 3, 4])
+            binary_fail = reduce(lambda x, y: x * y, [1, 2, 3, 4])
         """)
 
-        # Binary Op Test 1: This will not trigger a message
-        binary_pass = binary_root.body[0].body[0].value.args[0]
-        with self.assertNoMessages():
-            self.walk(binary_pass)
-
-        # Binary Op Test 2: This will not trigger a message
-        binary_pass2 = binary_root.body[0].body[1].value.args[0]
-        with self.assertNoMessages():
-            self.walk(binary_pass2)
-
-        # Binary Op Test 3: This will not trigger a message
-        binary_pass2 = binary_root.body[0].body[2].value.args[0]
-        with self.assertNoMessages():
-            self.walk(binary_pass2)
-
-        # Binary Op Test 3: This will trigger a message
         binary_msg = binary_root.body[0].body[3].value.args[0]
         bin_message = pylint.testutils.Message('lambda-func', node=binary_msg.body, args={
             'op': 'operator.mul',
-            'lamfun': 'lambda x, y: x * y'
+            'lambda_fcn': 'lambda x, y: x * y'
             })
         with self.assertAddsMessages(bin_message):
-            self.walk(binary_msg)
+            self.walk(binary_root)