Merge pull request #4128 from OlegAndreych:Fix_#4103

[java] Fix False-positive UnnecessaryFullyQualifiedName when nested and non-nest… #4103 #4128

.all-contributorsrc

@@ -6835,6 +6835,15 @@
       "contributions": [
         "financial"
       ]
+    },
+    {
+      "login": "OlegAndreych",
+      "name": "Oleg Andreych",
+      "avatar_url": "https://avatars.githubusercontent.com/u/2041351?v=4",
+      "profile": "https://github.com/OlegAndreych",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

docs/pages/release_notes.md

@@ -27,6 +27,8 @@ from Lua. This means, that the Lua language in PMD can now parse both Lua and Lu
 * doc
     * [#4109](https://github.com/pmd/pmd/pull/4109): \[doc] Add page for 3rd party rulesets
     * [#4124](https://github.com/pmd/pmd/pull/4124): \[doc] Fix typos in Java rule docs
+* java-codestyle
+    * [#4085](https://github.com/pmd/pmd/issues/4085): \[java] UnnecessaryFullyQualifiedName false positive when nested and non-nested classes with the same name and in the same package are used together
 
 ### API Changes
 
@@ -44,6 +46,7 @@ Many thanks to our sponsors:
 * [#4066](https://github.com/pmd/pmd/pull/4066): \[lua] Add support for Luau syntax and skipping literal sequences in CPD - [Matt Hargett](https://github.com/matthargett) (@matthargett)
 * [#4116](https://github.com/pmd/pmd/pull/4116): \[core] Fix missing --file arg in TreeExport CLI example - [mohan-chinnappan-n](https://github.com/mohan-chinnappan-n) (@mohan-chinnappan-n)
 * [#4124](https://github.com/pmd/pmd/pull/4124) : \[doc] Fix typos in Java rule docs - [Piotrek Żygieło](https://github.com/pzygielo) (@pzygielo)
+* [#4128](https://github.com/pmd/pmd/pull/4128): \[java] Fix False-positive UnnecessaryFullyQualifiedName when nested and non-nest… #4103 - [Oleg Andreych](https://github.com/OlegAndreych) (@OlegAndreych)
 * [#4131](https://github.com/pmd/pmd/pull/4131): \[doc] TooFewBranchesForASwitchStatement - Use "if-else" instead of "if-then" - [Suvashri](https://github.com/Suvashri) (@Suvashri)
 
 {% endtocmaker %}

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/codestyle/UnnecessaryFullyQualifiedNameRule.java

@@ -17,7 +17,9 @@ import java.util.logging.Logger;
 import org.apache.commons.lang3.StringUtils;
 
 import net.sourceforge.pmd.RuleContext;
+import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType;
+import net.sourceforge.pmd.lang.java.ast.ASTCompilationUnit;
 import net.sourceforge.pmd.lang.java.ast.ASTImportDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTName;
 import net.sourceforge.pmd.lang.java.ast.ASTNameList;
@@ -186,9 +188,12 @@ public class UnnecessaryFullyQualifiedNameRule extends AbstractJavaRule {
 
         if (matches.isEmpty()) {
             if (isJavaLangImplicit(node)) {
-                addViolation(data, node, new Object[] { node.getImage(), "java.lang.*", "implicit "});
+                asCtx(data).addViolation(node,
+                        node.getImage(), "java.lang.*", "implicit ");
             } else if (isSamePackage(node, name)) {
-                addViolation(data, node, new Object[] { node.getImage(), currentPackage + ".*", "same package "});
+                if (!hasSameSimpleNameInScope(node)) {
+                    asCtx(data).addViolation(node, node.getImage(), currentPackage + ".*", "same package ");
+                }
             }
         } else {
             ASTImportDeclaration firstMatch = findFirstMatch(matches);
@@ -199,11 +204,29 @@ public class UnnecessaryFullyQualifiedNameRule extends AbstractJavaRule {
                 String importStr = firstMatch.getImportedName() + (firstMatch.isImportOnDemand() ? ".*" : "");
                 String type = firstMatch.isStatic() ? "static " : "";
 
-                addViolation(data, node, new Object[] { node.getImage(), importStr, type });
+                asCtx(data).addViolation(node, node.getImage(), importStr, type);
             }
         }
     }
 
+    private boolean hasSameSimpleNameInScope(TypeNode node) {
+        final ASTCompilationUnit root = node.getRoot();
+        final List<ASTClassOrInterfaceDeclaration> declarationDescendants = root.findDescendantsOfType(ASTClassOrInterfaceDeclaration.class);
+        final Class<?> nodeType = node.getType();
+
+        if (nodeType == null) {
+            return false;
+        }
+
+        for (ASTClassOrInterfaceDeclaration declarationDescendant : declarationDescendants) {
+            if (nodeType.getSimpleName().equals(declarationDescendant.getSimpleName())
+                    && !nodeType.getName().equals(declarationDescendant.getQualifiedName().toString())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private ASTImportDeclaration findFirstMatch(List<ASTImportDeclaration> imports) {
         // first search only static imports
         ASTImportDeclaration result = null;
@@ -404,7 +427,7 @@ public class UnnecessaryFullyQualifiedNameRule extends AbstractJavaRule {
 
         // Is it a conflict with a class in the same file?
         final Set<String> qualifiedTypes = node.getScope().getEnclosingScope(SourceFileScope.class)
-                                               .getQualifiedTypeNames().keySet();
+                .getQualifiedTypeNames().keySet();
         for (final String qualified : qualifiedTypes) {
             int fullLength = qualified.length();
             if (qualified.endsWith(unqualifiedName)

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/codestyle/xml/UnnecessaryFullyQualifiedName.xml

@@ -622,6 +622,40 @@ public class UnnecessaryFullyQualifiedName {
         ]]></code>
     </test-code>
 
+    <test-code>
+        <description>False positive when same package inner class is referenced (not enum) #4085</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+package net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname;
+
+public class OuterTestClass {
+	public static class TestClass{
+        private final net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname.TestClass test;
+
+        public TestClass(net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname.TestClass test){
+
+            this.test = test;
+        }
+    }
+}
+        ]]></code>
+    </test-code>
+
+    <test-code>
+        <description>Should report fully-qualified name usage of a class in itself #4085</description>
+        <expected-problems>1</expected-problems>
+        <expected-linenumbers>4</expected-linenumbers>
+        <code><![CDATA[
+package net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname;
+
+public class TestClass {
+    public static net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname.TestClass INSTANCE(){
+        return new TestClass();
+    }
+}
+        ]]></code>
+    </test-code>
+
     <test-code>
         <description>#2098 false positive with annotated package</description>
         <expected-problems>0</expected-problems>