[#528] Fix chained method pattern and tests.

aibolit/patterns/method_chaining/method_chaining.py

@@ -5,43 +5,32 @@
 
 
 class MethodChainFind:
-    '''
-    In this pattern we check whether
-    more than one method chaining
-    invocation is used or not.
-    '''
-    def _is_invocation_inside(self, node: ASTNode) -> bool:
-        # to process structures such as:
-        # obj.methodInv1(list).methodInv2("blabla")
-        for i in node.children:
-            if i.node_type == ASTNodeType.METHOD_INVOCATION:
-                return True
-
-        return False
-
-    def _check_chained_method(self, ast: AST, method_invocation: ASTNode) -> bool:
-        childs = 0
-        for node in method_invocation.children:
-            if node.node_type == ASTNodeType.METHOD_INVOCATION:
-                # we check structures such as:
-                # new MyObject().Start()
-                #   .SpecifySomeParameter(list)
-                #   .SpecifySomeOtherParameter("list")
-                if self._is_invocation_inside(node) or node.qualifier is None:
-                    childs += 1
-        return childs > 0
+    """
+    Finds chained methods, i.e. foo().bar()
+    """
 
     def value(self, filename: str) -> List[int]:
         lines: List[int] = []
         ast = AST.build_from_javalang(build_ast(filename))
-        for stetement_expression in ast.get_proxy_nodes(ASTNodeType.STATEMENT_EXPRESSION):
-            expression_child = stetement_expression.expression
-            if expression_child.node_type == ASTNodeType.METHOD_INVOCATION and \
-                    self._check_chained_method(ast, expression_child):
-                lines.append(stetement_expression.line)
-
-            elif expression_child.node_type == ASTNodeType.CLASS_CREATOR and \
-                    len(expression_child.selectors) > 1:
-                lines.append(stetement_expression.line)
+        for node in ast.get_proxy_nodes(ASTNodeType.CLASS_CREATOR,
+                                        ASTNodeType.METHOD_INVOCATION,
+                                        ASTNodeType.THIS):
+            selectors_qty = self._get_selectors_qty(node)
+            if selectors_qty > MethodChainFind._allowed_number_of_selectord[node.node_type]:
+                lines.append(node.line)
 
         return lines
+
+    def _get_selectors_qty(self, node: ASTNode) -> int:
+        if not hasattr(node, "selectors") or node.selectors is None:
+            return 0
+
+        return len(node.selectors)
+
+    _allowed_number_of_selectord = {
+        # found node already is a method invocation, so no further invocations are allowed
+        ASTNodeType.METHOD_INVOCATION: 0,
+        ASTNodeType.THIS: 1,
+        # code example: new Object().foo().bar()
+        ASTNodeType.CLASS_CREATOR: 1,
+    }

test/patterns/method_chaining/NestedChainWIthThis.java

@@ -11,15 +11,17 @@ public void start() {
         );
 
 		obj = new Object();
-		obj.ohhhh().set(this.govno("Zh").zhopa(whaaat).concat(whaaat)).opopo(whaaat);
+		obj.ohhhh().set(
+            this.govno("Zh").zhopa(whaaat).concat(whaaat)
+        ).opopo(whaaat);
 		System.out.println("asdasd" + aaa + "34234" + bbb);
         list = new ArrayList<>();
         for (int i = 0; i < 10; i++)
             list.add(Boolean.FALSE);
         list = new ArrayList<>();
         for (int i = 0; i < 10; i++)
             list.add(Boolean.FALSE);
-		
+
     }
 
 

test/patterns/method_chaining/NestedChainWithSimpleMethodInvocation.java

@@ -12,15 +12,17 @@ public void start() {
 
 		obj = new Object();
 		obj1 = new Object();
-		obj.dummy1().dummy2(obj1.foo1("Zh").foo2(whaaat).foo3(whaaat)).dummy3(whaaat);
+		obj.dummy1().dummy2(
+            obj1.foo1("Zh").foo2(whaaat).foo3(whaaat)
+        ).dummy3(whaaat);
 		System.out.println("asdasd" + aaa + "34234" + bbb);
         list = new ArrayList<>();
         for (int i = 0; i < 10; i++)
             list.add(Boolean.FALSE);
         list = new ArrayList<>();
         for (int i = 0; i < 10; i++)
             list.add(Boolean.FALSE);
-		
+
     }
 
 

test/patterns/method_chaining/test_method_chaining.py

@@ -40,7 +40,7 @@ def test_empty_method_chain(self):
 
     def test_chain_with_new_object(self):
         lines = self.method_chain_finder.value(Path(self.dir_path, 'MethodChainNewObjectMethods.java'))
-        self.assertEqual(lines, [34])
+        self.assertEqual(lines, [23, 34])
 
     def test_method_chain_in_different_methods(self):
         lines = self.method_chain_finder.value(Path(self.dir_path, 'MethodChainInDifferentMethods.java'))
@@ -68,11 +68,11 @@ def test_chain_without_object_creating(self):
 
     def test_nested_chain_with_this(self):
         lines = self.method_chain_finder.value(Path(self.dir_path, 'NestedChainWIthThis.java'))
-        self.assertEqual(lines, [14])
+        self.assertEqual(lines, [14, 15])
 
     def test_nested_chain_with_simple_method_invocation(self):
         lines = self.method_chain_finder.value(Path(self.dir_path, 'NestedChainWithSimpleMethodInvocation.java'))
-        self.assertEqual(lines, [15])
+        self.assertEqual(lines, [15, 16])
 
     def test_nested_chain_complicated_structure(self):
         """
@@ -84,7 +84,7 @@ def test_nested_chain_complicated_structure(self):
 
     def test_smallest_chain(self):
         lines = self.method_chain_finder.value(Path(self.dir_path, 'SmallestChain.java'))
-        self.assertEqual(lines, [31])
+        self.assertEqual(lines, [31, 83, 84])
 
     def test_fake_chain(self):
         lines = self.method_chain_finder.value(Path(self.dir_path, 'FakeChain.java'))