Issue checkstyle#79: Processing UT changes to get possible property v…

…alues

config/import-control.xml

@@ -51,4 +51,9 @@
         <allow pkg="org.eclipse.jgit"/>
         <allow pkg="org.apache.commons.lang"/>
     </subpackage>
+
+    <subpackage name="module">
+        <allow pkg="com.puppycrawl.tools.checkstyle"/>
+        <allow class="java.lang.reflect.Field"/>
+    </subpackage>
 </import-control>

config/pmd.xml

@@ -34,7 +34,11 @@
     <!-- we use class comments as source for xdoc files, so content is big and that is by design -->
     <exclude name="CommentSize"/>
   </rule>
-  <rule ref="rulesets/java/comments.xml/CommentRequired" />
+  <rule ref="rulesets/java/comments.xml/CommentRequired">
+    <properties>
+      <property name="publicMethodCommentRequirement" value="Ignored"/>
+    </properties>
+  </rule>
   <rule ref="rulesets/java/comments.xml/CommentSize">
     <properties>
       <!-- we use class comments as source for xdoc files, so content is big and that is by design -->

pom.xml

@@ -393,6 +393,11 @@
                                         <branchRate>0</branchRate>
                                         <lineRate>0</lineRate>
                                     </regex>
+                                    <regex>
+                                        <pattern>com.github.checkstyle.regression.module.UnitTestProcessorCheck</pattern>
+                                        <branchRate>76</branchRate>
+                                        <lineRate>92</lineRate>
+                                    </regex>
                                     <regex>
                                         <pattern>com.github.checkstyle.regression.report.ReportGenerator</pattern>
                                         <branchRate>0</branchRate>

src/main/java/com/github/checkstyle/regression/module/UnitTestProcessor.java

@@ -0,0 +1,115 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+package com.github.checkstyle.regression.module;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import com.github.checkstyle.regression.data.ModuleInfo;
+import com.puppycrawl.tools.checkstyle.Checker;
+import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.TreeWalker;
+import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
+import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
+import com.puppycrawl.tools.checkstyle.api.Configuration;
+import com.puppycrawl.tools.checkstyle.api.FileSetCheck;
+
+/**
+ * Processes the unit test class of a checkstyle module.
+ * This utility class would run {@link UnitTestProcessorCheck} on the file with
+ * the given path and return the collected property info.
+ * @author LuoLiangchen
+ */
+public final class UnitTestProcessor {
+    /** Prevents instantiation. */
+    private UnitTestProcessor() {
+    }
+
+    /**
+     * Processes the unit test class with the given path.
+     * @param path the path of the unit test class
+     * @return the unit test method name to properties map
+     * @throws CheckstyleException          failure when running the check
+     * @throws ReflectiveOperationException failure of reflection on checker and tree walker
+     */
+    public static Map<String, Set<ModuleInfo.Property>> process(String path)
+            throws CheckstyleException, ReflectiveOperationException {
+        final DefaultConfiguration moduleConfig = createModuleConfig(UnitTestProcessorCheck.class);
+        final Configuration dc = createTreeWalkerConfig(moduleConfig);
+        final Checker checker = new Checker();
+        checker.setModuleClassLoader(Thread.currentThread().getContextClassLoader());
+        checker.configure(dc);
+        final List<File> processedFiles = Collections.singletonList(new File(path));
+        checker.process(processedFiles);
+
+        final UnitTestProcessorCheck check = getCheckInstance(checker);
+        return check.getUnitTestToPropertiesMap();
+    }
+
+    /**
+     * Gets the instance of {@link UnitTestProcessorCheck} from the checker.
+     * @param checker the checker which run the check
+     * @return the instance of {@link UnitTestProcessorCheck}
+     * @throws ReflectiveOperationException failure of reflection
+     */
+    @SuppressWarnings("unchecked")
+    private static UnitTestProcessorCheck getCheckInstance(Checker checker)
+            throws ReflectiveOperationException {
+        final Field fileSetChecks = checker.getClass().getDeclaredField("fileSetChecks");
+        fileSetChecks.setAccessible(true);
+        final TreeWalker treeWalker =
+                (TreeWalker) ((List<FileSetCheck>) fileSetChecks.get(checker)).get(0);
+        final Field ordinaryChecks = treeWalker.getClass().getDeclaredField("ordinaryChecks");
+        ordinaryChecks.setAccessible(true);
+        final Set<AbstractCheck> checks = (Set<AbstractCheck>) ordinaryChecks.get(treeWalker);
+        return (UnitTestProcessorCheck) checks.iterator().next();
+    }
+
+    /**
+     * Creates {@link DefaultConfiguration} for the {@link TreeWalker}
+     * based on the given {@link Configuration} instance.
+     * @param config {@link Configuration} instance.
+     * @return {@link DefaultConfiguration} for the {@link TreeWalker}
+     *      based on the given {@link Configuration} instance.
+     */
+    private static DefaultConfiguration createTreeWalkerConfig(Configuration config) {
+        final DefaultConfiguration dc =
+                new DefaultConfiguration("configuration");
+        final DefaultConfiguration twConf = createModuleConfig(TreeWalker.class);
+        // make sure that the tests always run with this charset
+        dc.addAttribute("charset", "UTF-8");
+        dc.addChild(twConf);
+        twConf.addChild(config);
+        return dc;
+    }
+
+    /**
+     * Creates {@link DefaultConfiguration} for the given class.
+     * @param clazz the class of module
+     * @return the {@link DefaultConfiguration} of the module class
+     */
+    private static DefaultConfiguration createModuleConfig(Class<?> clazz) {
+        return new DefaultConfiguration(clazz.getName());
+    }
+}

src/main/java/com/github/checkstyle/regression/module/UnitTestProcessorCheck.java

@@ -0,0 +1,211 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2017 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+////////////////////////////////////////////////////////////////////////////////
+
+package com.github.checkstyle.regression.module;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+import com.github.checkstyle.regression.data.ImmutableProperty;
+import com.github.checkstyle.regression.data.ModuleInfo;
+import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+
+/**
+ * The custom check which processes the unit test class of a checkstyle module.
+ * This check would walk through the {@code @Test} annotation, find variable definition
+ * like {@code final DefaultConfiguration checkConfig = createModuleConfig(FooCheck.class)}
+ * and grab the property info from {@link DefaultConfiguration#addAttribute(String, String)}
+ * method call.
+ * @author LuoLiangchen
+ */
+public class UnitTestProcessorCheck extends AbstractCheck {
+    /** The map of unit test method name to properties. */
+    private final Map<String, Set<ModuleInfo.Property>> unitTestToProperties =
+            new LinkedHashMap<>();
+
+    @Override
+    public int[] getDefaultTokens() {
+        return new int[] {
+            TokenTypes.ANNOTATION,
+        };
+    }
+
+    @Override
+    public int[] getRequiredTokens() {
+        return new int[] {
+            TokenTypes.ANNOTATION,
+        };
+    }
+
+    @Override
+    public int[] getAcceptableTokens() {
+        return new int[] {
+            TokenTypes.ANNOTATION,
+        };
+    }
+
+    @Override
+    public void visitToken(DetailAST ast) {
+        if ("Test".equals(ast.findFirstToken(TokenTypes.IDENT).getText())) {
+            final DetailAST methodDef = ast.getParent().getParent();
+            final DetailAST methodBlock = methodDef.findFirstToken(TokenTypes.SLIST);
+            final Optional<String> configVariableName =
+                    getModuleConfigVariableName(methodBlock);
+            if (configVariableName.isPresent()) {
+                final Set<ModuleInfo.Property> properties = new LinkedHashSet<>();
+
+                for (DetailAST expr : getAllChildrenWithToken(methodBlock, TokenTypes.EXPR)) {
+                    if (isAddAttributeMethodCall(expr.getFirstChild(), configVariableName.get())) {
+                        final DetailAST elist =
+                                expr.getFirstChild().findFirstToken(TokenTypes.ELIST);
+                        final String key = convertExprToText(elist.getFirstChild());
+                        final String value = convertExprToText(elist.getLastChild());
+                        properties.add(ImmutableProperty.builder().name(key).value(value).build());
+                    }
+                }
+
+                if (!unitTestToProperties.containsValue(properties)) {
+                    final String methodName = methodDef.findFirstToken(TokenTypes.IDENT).getText();
+                    unitTestToProperties.put(methodName, properties);
+                }
+            }
+        }
+    }
+
+    /**
+     * Gets the map of unit test method name to properties.
+     * @return the map of unit test method name to properties
+     */
+    public Map<String, Set<ModuleInfo.Property>> getUnitTestToPropertiesMap() {
+        return Collections.unmodifiableMap(unitTestToProperties);
+    }
+
+    /**
+     * Gets the module config variable name, if it exists.
+     * @param methodBlock the UT method block ast, which should have a type {@link TokenTypes#SLIST}
+     * @return the optional variable name, if it exists
+     */
+    private static Optional<String> getModuleConfigVariableName(DetailAST methodBlock) {
+        Optional<String> returnValue = Optional.empty();
+
+        for (DetailAST ast = methodBlock.getFirstChild(); ast != null; ast = ast.getNextSibling()) {
+            if (ast.getType() == TokenTypes.VARIABLE_DEF) {
+                final DetailAST type = ast.findFirstToken(TokenTypes.TYPE);
+                final DetailAST assign = ast.findFirstToken(TokenTypes.ASSIGN);
+                if (isDefaultConfigurationType(type) && isCreateModuleConfigAssign(assign)) {
+                    returnValue = Optional.of(type.getNextSibling().getText());
+                    break;
+                }
+            }
+        }
+
+        return returnValue;
+    }
+
+    /**
+     * Checks whether this {@link TokenTypes#TYPE} ast is {@link DefaultConfiguration}.
+     * @param ast the {@link TokenTypes#TYPE} ast
+     * @return true if the type is {@link DefaultConfiguration}
+     */
+    private static boolean isDefaultConfigurationType(DetailAST ast) {
+        return "DefaultConfiguration".equals(ast.getFirstChild().getText());
+    }
+
+    /**
+     * Checks whether this {@link TokenTypes#ASSIGN} ast contains
+     * a {@code createModuleConfig} method call.
+     * @param ast the {@link TokenTypes#ASSIGN} ast
+     * @return true if the assignment contains a {@code createModuleConfig} method call
+     */
+    private static boolean isCreateModuleConfigAssign(DetailAST ast) {
+        final boolean result;
+
+        if (ast == null) {
+            result = false;
+        }
+        else {
+            final DetailAST exprChild = ast.getFirstChild().getFirstChild();
+            result = exprChild.getType() == TokenTypes.METHOD_CALL
+                    && exprChild.getFirstChild().getType() == TokenTypes.IDENT
+                    && "createModuleConfig".equals(exprChild.getFirstChild().getText());
+        }
+
+        return result;
+    }
+
+    /**
+     * Gets all children of a ast with the given tokens type.
+     * @param parent the parent ast
+     * @param type   the given tokens type
+     * @return the children with the given tokens type
+     */
+    private static List<DetailAST> getAllChildrenWithToken(DetailAST parent, int type) {
+        final List<DetailAST> returnValue = new LinkedList<>();
+
+        for (DetailAST ast = parent.getFirstChild(); ast != null; ast = ast.getNextSibling()) {
+            if (ast.getType() == type) {
+                returnValue.add(ast);
+            }
+        }
+
+        return returnValue;
+    }
+
+    /**
+     * Checks whether this expression is an {@code addAttribute} method call on an instance with
+     * the given variable name.
+     * @param ast          the ast to check
+     * @param variableName the given variable name of the module config instance
+     * @return true if the expression is a valid {@code addAttribute} method call
+     */
+    private static boolean isAddAttributeMethodCall(DetailAST ast, String variableName) {
+        final boolean result;
+
+        if (ast.getType() == TokenTypes.METHOD_CALL
+                && ast.getFirstChild().getType() == TokenTypes.DOT) {
+            final DetailAST dot = ast.getFirstChild();
+            result = variableName.equals(dot.getFirstChild().getText())
+                    && "addAttribute".equals(dot.getLastChild().getText());
+        }
+        else {
+            result = false;
+        }
+
+        return result;
+    }
+
+    /**
+     * Converts an expression to raw text.
+     * @param ast the expression ast to convert
+     * @return the converted raw text
+     */
+    private static String convertExprToText(DetailAST ast) {
+        final String original = ast.getFirstChild().getText();
+        return original.substring(1, original.length() - 1);
+    }
+}