Relax NoWhitespaceBeforeCheck to allow annotated varags

Closes gh-454

Author: wilkinsona

spring-javaformat/spring-javaformat-checkstyle/src/main/java/io/spring/javaformat/checkstyle/check/SpringNoWhitespaceBeforeCheck.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2017-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.javaformat.checkstyle.check;
+
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+import com.puppycrawl.tools.checkstyle.checks.whitespace.NoWhitespaceBeforeCheck;
+
+/**
+ * Spring-specific customization of {@link NoWhitespaceBeforeCheck} that permits
+ * whitespace before {@code ...} when it is a separator after an annotation, for
+ * example {@code int @Nullable ...}.
+ *
+ * @author Andy Wilkinson
+ */
+public class SpringNoWhitespaceBeforeCheck extends NoWhitespaceBeforeCheck {
+
+	@Override
+	public void visitToken(DetailAST ast) {
+		if (ast.getType() != TokenTypes.ELLIPSIS) {
+			super.visitToken(ast);
+		}
+		else {
+			visitEllipsis(ast);
+		}
+	}
+
+	private void visitEllipsis(DetailAST ellipsis) {
+		DetailAST previousSibling = ellipsis.getPreviousSibling();
+		if (previousSibling.getType() == TokenTypes.TYPE &&
+				previousSibling.getChildCount() == 2 &&
+				previousSibling.getLastChild().getType() == TokenTypes.ANNOTATIONS) {
+			return;
+		}
+		super.visitToken(ellipsis);
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/main/resources/io/spring/javaformat/checkstyle/spring-checkstyle.xml

@@ -145,7 +145,7 @@
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.NoWhitespaceAfterCheck" >
 			<property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS, ARRAY_DECLARATOR"/>
 		</module>
-		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.NoWhitespaceBeforeCheck" />
+		<module name="io.spring.javaformat.checkstyle.check.SpringNoWhitespaceBeforeCheck" />
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.TypecastParenPadCheck" />
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAfterCheck" />
 		<module name="com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAroundCheck" />

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/WhitespaceNullableArray.txt

@@ -0,0 +1 @@
++0 errors

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/WhitespaceNullableArrayElements.txt

@@ -0,0 +1 @@
++0 errors

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/WhitespaceNullableVarargs.txt

@@ -0,0 +1 @@
++0 errors

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/WhitespaceVarargs.txt

@@ -0,0 +1,2 @@
++WhitespaceVarargs.java:24:24: '...' is preceded with whitespace. [SpringNoWhitespaceBefore]
++1 error

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/WhitespaceNullableArray.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2017-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Whitespace is expected before {@code []} when @Nullable.
+ *
+ * @author Andy Wilkinson
+ */
+public class WhitespaceNullableArray {
+
+	void bytes(int @Nullable [] elements) {
+
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/WhitespaceNullableArrayElements.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2017-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Whitespace is expected before {@code type[]} when @Nullable.
+ *
+ * @author Andy Wilkinson
+ */
+public class WhitespaceNullableArrayElements {
+
+	void bytes(@Nullable int[] elements) {
+
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/WhitespaceNullableVarargs.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2017-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Whitespace is expected before ... when @Nullable.
+ *
+ * @author Andy Wilkinson
+ */
+public class WhitespaceNullableVarargs {
+
+	void bytes(int @Nullable ... elements) {
+
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/WhitespaceVarargs.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2017-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Whitespace is not expected before {@code ...}.
+ *
+ * @author Andy Wilkinson
+ */
+public class WhitespaceVarargs {
+
+	void bytes(int ... elements) {
+
+	}
+
+}