Issue #3329: Added lambda to ParenPad

9 files changed, 258 insertions, 6 deletions

diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheck.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheck.java
index e152fd586..62a127da5 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheck.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheck.java
@@ -61,6 +61,7 @@ import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
  *  {@link TokenTypes#RESOURCE_SPECIFICATION RESOURCE_SPECIFICATION},
  *  {@link TokenTypes#SUPER_CTOR_CALL SUPER_CTOR_CALL},
  *  {@link TokenTypes#QUESTION QUESTION},
+ *  {@link TokenTypes#LAMBDA LAMBDA},
  * </p>
  * <p>
  * An example of how to configure the check is:
@@ -131,7 +132,8 @@ public class ParenPadCheck extends AbstractParenPadCheck {
             case TokenTypes.ENUM_CONSTANT_DEF:
             case TokenTypes.LITERAL_NEW:
             case TokenTypes.LITERAL_SYNCHRONIZED:
-                visitNewEnumConstDefAnnotationSync(ast);
+            case TokenTypes.LAMBDA:
+                visitTokenWithOptionalParentheses(ast);
                 break;
             default:
                 processLeft(ast.findFirstToken(TokenTypes.LPAREN));
@@ -140,11 +142,13 @@ public class ParenPadCheck extends AbstractParenPadCheck {
     }
 
     /**
-     * Checks parens in {@link TokenTypes#ENUM_CONSTANT_DEF}, {@link TokenTypes#ANNOTATION}
-     * {@link TokenTypes#LITERAL_SYNCHRONIZED} and {@link TokenTypes#LITERAL_NEW}.
+     * Checks parens in token which may not contain parens, e.g.
+     * {@link TokenTypes#ENUM_CONSTANT_DEF}, {@link TokenTypes#ANNOTATION}
+     * {@link TokenTypes#LITERAL_SYNCHRONIZED}, {@link TokenTypes#LITERAL_NEW} and
+     * {@link TokenTypes#LAMBDA}.
      * @param ast the token to check.
      */
-    private void visitNewEnumConstDefAnnotationSync(DetailAST ast) {
+    private void visitTokenWithOptionalParentheses(DetailAST ast) {
         final DetailAST parenAst = ast.findFirstToken(TokenTypes.LPAREN);
         if (parenAst != null) {
             processLeft(parenAst);
@@ -229,6 +233,7 @@ public class ParenPadCheck extends AbstractParenPadCheck {
             TokenTypes.QUESTION,
             TokenTypes.RESOURCE_SPECIFICATION,
             TokenTypes.SUPER_CTOR_CALL,
+            TokenTypes.LAMBDA,
         };
     }
 
diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheckTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheckTest.java
index b80c6d78b..c0d402b45 100644
--- a/src/test/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheckTest.java
+++ b/src/test/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheckTest.java
@@ -262,4 +262,103 @@ public class ParenPadCheckTest
                             + "Cannot set property 'option' to 'invalid_option' in module"));
         }
     }
+
+    @Test
+    public void testLambdaAssignment() throws Exception {
+        final DefaultConfiguration checkConfig = createCheckConfig(ParenPadCheck.class);
+        final String[] expected = {
+            "9:42: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "9:44: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "11:43: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "13:42: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "15:47: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "15:49: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "17:47: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "17:56: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "19:62: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "19:62: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "22:21: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "22:34: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+        };
+        verify(checkConfig, getPath("InputParenPadLambda.java"), expected);
+    }
+
+    @Test
+    public void testLambdaAssignmentWithSpace() throws Exception {
+        final DefaultConfiguration checkConfig = createCheckConfig(ParenPadCheck.class);
+        checkConfig.addAttribute("option", PadOption.SPACE.toString());
+        final String[] expected = {
+            "9:42: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "9:43: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "11:42: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "13:44: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "15:48: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "15:49: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "17:48: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "17:56: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "22:21: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "22:33: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+        };
+        verify(checkConfig, getPath("InputParenPadLambdaWithSpace.java"), expected);
+    }
+
+    @Test
+    public void testLambdaCheckDisabled() throws Exception {
+        final DefaultConfiguration checkConfig = createCheckConfig(ParenPadCheck.class);
+        checkConfig.addAttribute("tokens", "EXPR, METHOD_CALL, METHOD_DEF");
+        final String[] expected = {
+            "19:62: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "19:62: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "22:21: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "22:34: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+        };
+        verify(checkConfig, getPath("InputParenPadWithDisabledLambda.java"), expected);
+    }
+
+    @Test
+    public void testLambdaCheckDisabledWithSpace() throws Exception {
+        final DefaultConfiguration checkConfig = createCheckConfig(ParenPadCheck.class);
+        checkConfig.addAttribute("option", PadOption.SPACE.toString());
+        checkConfig.addAttribute("tokens", "EXPR, METHOD_CALL, METHOD_DEF");
+        final String[] expected = {
+            "22:21: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "22:33: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+        };
+        verify(checkConfig, getPath("InputParenPadWithSpaceAndDisabledLambda.java"), expected);
+    }
+
+    @Test
+    public void testLambdaCheckOnly() throws Exception {
+        final DefaultConfiguration checkConfig = createCheckConfig(ParenPadCheck.class);
+        checkConfig.addAttribute("tokens", "LAMBDA");
+        final String[] expected = {
+            "9:42: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "9:44: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "11:43: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "13:42: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "15:47: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "15:49: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+            "17:47: " + getCheckMessage(MSG_WS_FOLLOWED, "("),
+            "17:56: " + getCheckMessage(MSG_WS_PRECEDED, ")"),
+        };
+        verify(checkConfig, getPath("InputParenPadLambdaOnly.java"), expected);
+    }
+
+    @Test
+    public void testLambdaCheckOnlyWithSpace() throws Exception {
+        final DefaultConfiguration checkConfig = createCheckConfig(ParenPadCheck.class);
+        checkConfig.addAttribute("option", PadOption.SPACE.toString());
+        checkConfig.addAttribute("tokens", "LAMBDA");
+        final String[] expected = {
+            "9:42: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "9:43: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "11:42: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "13:44: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "15:48: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "15:49: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+            "17:48: " + getCheckMessage(MSG_WS_NOT_FOLLOWED, "("),
+            "17:56: " + getCheckMessage(MSG_WS_NOT_PRECEDED, ")"),
+        };
+        verify(checkConfig, getPath("InputParenPadLambdaOnlyWithSpace.java"), expected);
+    }
 }
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambda.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambda.java
new file mode 100644
index 000000000..eeaa9c87b
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambda.java
@@ -0,0 +1,24 @@
+package com.puppycrawl.tools.checkstyle.checks.whitespace;
+
+class InputParenPadLambda {
+    {
+        java.util.function.Consumer a = (o) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer b = o -> { o.toString(); }; // ok
+
+        java.util.function.Consumer c = ( o ) -> { o.toString(); }; // 2 violations
+
+        java.util.function.Consumer d = (o ) -> { o.toString(); }; // 1 violation
+
+        java.util.function.Consumer e = ( o) -> { o.toString(); }; // 1 violation
+
+        java.util.stream.Stream.of().forEach(( o ) -> o.toString()); // 2 violations
+
+        java.util.stream.Stream.of().forEach(( Object o ) -> o.toString()); // 2 violations
+
+        java.util.stream.Stream.of().forEach(o -> o.toString( )); // 2 violations
+    }
+
+    void someMethod( String param ) { // 2 violations
+    }
+}
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaOnly.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaOnly.java
new file mode 100644
index 000000000..da6d2bb40
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaOnly.java
@@ -0,0 +1,24 @@
+package com.puppycrawl.tools.checkstyle.checks.whitespace;
+
+public class InputParenPadLambdaOnly {
+    {
+        java.util.function.Consumer a = (o) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer b = o -> { o.toString(); }; // ok
+
+        java.util.function.Consumer c = ( o ) -> { o.toString(); }; // 2 violations
+
+        java.util.function.Consumer d = (o ) -> { o.toString(); }; // 1 violation
+
+        java.util.function.Consumer e = ( o) -> { o.toString(); }; // 1 violation
+
+        java.util.stream.Stream.of().forEach(( o ) -> o.toString()); // 2 violations
+
+        java.util.stream.Stream.of().forEach(( Object o ) -> o.toString()); // 2 violations
+
+        java.util.stream.Stream.of().forEach(o -> o.toString( )); // ok
+    }
+
+    void someMethod( String param ) { // ok
+    }
+}
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaOnlyWithSpace.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaOnlyWithSpace.java
new file mode 100644
index 000000000..6a0c5e073
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaOnlyWithSpace.java
@@ -0,0 +1,24 @@
+package com.puppycrawl.tools.checkstyle.checks.whitespace;
+
+class InputParenPadLambdaOnlyWithSpace {
+    {
+        java.util.function.Consumer a = ( o ) -> { o.toString( ); }; // ok
+
+        java.util.function.Consumer b = o -> { o.toString(); }; // ok
+
+        java.util.function.Consumer c = (o) -> { o.toString(); }; // 2 violations
+
+        java.util.function.Consumer d = (o ) -> { o.toString(); }; // 1 violation
+
+        java.util.function.Consumer e = ( o) -> { o.toString(); }; // 1 violation
+
+        java.util.stream.Stream.of().forEach( (o) -> o.toString() ); // 2 violations
+
+        java.util.stream.Stream.of().forEach( (Object o) -> o.toString() ); // 2 violations
+
+        java.util.stream.Stream.of().forEach( o -> o.toString() ); // ok
+    }
+
+    void someMethod(String param) { // ok
+    }
+}
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaWithSpace.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaWithSpace.java
new file mode 100644
index 000000000..5350b4185
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadLambdaWithSpace.java
@@ -0,0 +1,24 @@
+package com.puppycrawl.tools.checkstyle.checks.whitespace;
+
+class InputParenPadLambdaWithSpace {
+    {
+        java.util.function.Consumer a = ( o ) -> { o.toString( ); }; // ok
+
+        java.util.function.Consumer b = o -> { o.toString(); }; // ok
+
+        java.util.function.Consumer c = (o) -> { o.toString(); }; // 2 violations
+
+        java.util.function.Consumer d = (o ) -> { o.toString(); }; // 1 violation
+
+        java.util.function.Consumer e = ( o) -> { o.toString(); }; // 1 violation
+
+        java.util.stream.Stream.of().forEach( (o) -> o.toString() ); // 2 violations
+
+        java.util.stream.Stream.of().forEach( (Object o) -> o.toString() ); // 2 violations
+
+        java.util.stream.Stream.of().forEach( o -> o.toString() ); // ok
+    }
+
+    void someMethod(String param) { // 2 violations
+    }
+}
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadWithDisabledLambda.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadWithDisabledLambda.java
new file mode 100644
index 000000000..1dccad6f4
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadWithDisabledLambda.java
@@ -0,0 +1,24 @@
+package com.puppycrawl.tools.checkstyle.checks.whitespace;
+
+public class InputParenPadWithDisabledLambda {
+    {
+        java.util.function.Consumer a = (o) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer b = o -> { o.toString(); }; // ok
+
+        java.util.function.Consumer c = ( o ) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer d = (o ) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer e = ( o) -> { o.toString(); }; // ok
+
+        java.util.stream.Stream.of().forEach(( o ) -> o.toString()); // ok
+
+        java.util.stream.Stream.of().forEach(( Object o ) -> o.toString()); // ok
+
+        java.util.stream.Stream.of().forEach(o -> o.toString( )); // 2 violations
+    }
+
+    void someMethod( String param ) { // 2 violations
+    }
+}
diff --git a/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadWithSpaceAndDisabledLambda.java b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadWithSpaceAndDisabledLambda.java
new file mode 100644
index 000000000..b8df6a97b
--- /dev/null
+++ b/src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/InputParenPadWithSpaceAndDisabledLambda.java
@@ -0,0 +1,24 @@
+package com.puppycrawl.tools.checkstyle.checks.whitespace;
+
+class InputParenPadWithSpaceAndDisabledLambda {
+    {
+        java.util.function.Consumer a = ( o ) -> { o.toString( ); }; // ok
+
+        java.util.function.Consumer b = o -> { o.toString(); }; // ok
+
+        java.util.function.Consumer c = (o) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer d = (o ) -> { o.toString(); }; // ok
+
+        java.util.function.Consumer e = ( o) -> { o.toString(); }; // ok
+
+        java.util.stream.Stream.of().forEach( (o) -> o.toString() ); // ok
+
+        java.util.stream.Stream.of().forEach( (Object o) -> o.toString() ); // ok
+
+        java.util.stream.Stream.of().forEach( o -> o.toString() ); // ok
+    }
+
+    void someMethod(String param) { // 2 violations
+    }
+}
diff --git a/src/xdocs/config_whitespace.xml b/src/xdocs/config_whitespace.xml
index 49513b772..f52e5ab69 100644
--- a/src/xdocs/config_whitespace.xml
+++ b/src/xdocs/config_whitespace.xml
@@ -1411,7 +1411,9 @@ import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
               <a
               href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RESOURCE_SPECIFICATION">RESOURCE_SPECIFICATION</a>,
               <a
-              href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL">SUPER_CTOR_CALL</a>.
+              href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL">SUPER_CTOR_CALL</a>,
+              <a
+              href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LAMBDA">LAMBDA</a>.
             </td>
 
             <td>
@@ -1452,7 +1454,9 @@ import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
               <a
               href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RESOURCE_SPECIFICATION">RESOURCE_SPECIFICATION</a>,
               <a
-              href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL">SUPER_CTOR_CALL</a>.
+              href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#SUPER_CTOR_CALL">SUPER_CTOR_CALL</a>,
+              <a
+              href="apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LAMBDA">LAMBDA</a>.
             </td>
           </tr>
         </table>