For #738: Qulaify inner classes

qulice-checkstyle/src/main/java/com/qulice/checkstyle/QualifyInnerClassCheck.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2011-2019, Qulice.com
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met: 1) Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer. 2) Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution. 3) Neither the name of the Qulice.com nor
+ * the names of its contributors may be used to endorse or promote
+ * products derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
+ * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.qulice.checkstyle;
+
+import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
+
+/**
+ * Checks if inner classes are properly accessed using their qualified name
+ * with the outer class.
+ *
+ * @since 0.18
+ * @todo #738:30min Static inner classes should be qualified with outer class
+ *  Implement QualifyInnerClassCheck so it follows what defined in
+ *  QualifyInnerClassCheck test and add this check to checks.xml and CheckTest.
+ */
+public final class QualifyInnerClassCheck extends AbstractCheck {
+    @Override
+    public int[] getDefaultTokens() {
+        throw new UnsupportedOperationException(
+            "getDefaultTokens() not implemented"
+        );
+    }
+
+    @Override
+    public int[] getAcceptableTokens() {
+        throw new UnsupportedOperationException(
+            "getAcceptableTokens() not implemented"
+        );
+    }
+
+    @Override
+    public int[] getRequiredTokens() {
+        throw new UnsupportedOperationException(
+            "getRequiredTokens() not implemented"
+        );
+    }
+}

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/QualifyInnerClassCheck/Invalid.java

@@ -0,0 +1,19 @@
+/*
+ * This is not a real Java class. It won't be compiled ever. It is used
+ * only as a text resource in integration.ChecksIT.
+ */
+public final class Invalid {
+
+    public void method(int num) {
+        new Bar(num);
+    }
+
+    private static final class Bar {
+
+        private final int member;
+
+        Bar(int num) {
+            this.member = num;
+        }
+    }
+}

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/QualifyInnerClassCheck/Valid.java

@@ -0,0 +1,18 @@
+/*
+ * This is not a real Java class. It won't be compiled ever. It is used
+ * only as a text resource in integration.ChecksIT.
+ */
+public final class Valid {
+
+    public void method(int num) {
+        new Valid.Bar(num);
+    }
+
+    private static final class Bar {
+        private final int num;
+
+        Bar(int num) {
+            this.num = num;
+        }
+    }
+}

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/QualifyInnerClassCheck/config.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
+    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!--
+ * This is not a real Checkstyle config. It is used
+ * only as a text resource in integration.ChecksIT.
+ -->
+<module name="Checker">
+    <module name="TreeWalker">
+    <module name="com.qulice.checkstyle.QualifyInnerClassCheck"/>
+    </module>
+</module>

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/QualifyInnerClassCheck/violations.txt

@@ -0,0 +1 @@
+8:Static inner class should be qualified with outer class