GCI91 - Create rule 'Use filter before sort' in java context - V.E.R.T.

CHANGELOG.md

@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- [GCI91](https://github.com/green-code-initiative/creedengo-java/pull/111) New rule to detect if a sort method is called before a filter in stream
+
 ### Changed
 
 - [#103](https://github.com/green-code-initiative/creedengo-java/pull/103) GCI69 Java : calls to hasMoreElements() and nextElement() methods from java.util.Enumeration interface aren't flagged anymore when called in a for loop

pom.xml

@@ -78,7 +78,7 @@
         <google.re2j>1.8</google.re2j>
 
         <!-- Version of creedengo rules specifications implemented by this plugin -->
-        <creedengo-rules-specifications.version>2.2.2</creedengo-rules-specifications.version>
+        <creedengo-rules-specifications.version>2.2.3</creedengo-rules-specifications.version>
 
         <!-- URL of the Maven repository where sonarqube will be downloaded -->
         <test-it.orchestrator.artifactory.url>https://repo1.maven.org/maven2</test-it.orchestrator.artifactory.url>
@@ -231,6 +231,10 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.13.0</version>
+                <configuration>
+                    <source>16</source>
+                    <target>16</target>
+                </configuration>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>

src/it/java/org/greencodeinitiative/creedengo/java/integration/tests/GCIRulesIT.java

@@ -1,6 +1,7 @@
 package org.greencodeinitiative.creedengo.java.integration.tests;
 
 import org.junit.jupiter.api.Test;
+import org.sonarqube.ws.Common;
 import org.sonarqube.ws.Issues;
 import org.sonarqube.ws.Measures;
 
@@ -548,4 +549,15 @@ void testGCI94() {
         checkIssuesForFile(filePath, ruleId, ruleMsg, startLines, endLines, SEVERITY, TYPE, EFFORT_1MIN);
     }
 
+    @Test
+    void testGCI91() {
+        String filePath = "src/main/java/org/greencodeinitiative/creedengo/java/checks/UseFilterBeforeSort.java";
+        String ruleId = "creedengo-java:GCI91";
+        String ruleMsg = "Use 'filter' before 'sorted' for better efficiency.";
+        int[] startLines = new int[]{11,16};
+        int[] endLines = new int[]{14, 20};
+
+        checkIssuesForFile(filePath, ruleId, ruleMsg, startLines, endLines, Common.Severity.MAJOR, TYPE, EFFORT_5MIN);
+    }
+
 }

src/it/test-projects/creedengo-java-plugin-test-project/src/main/java/org/greencodeinitiative/creedengo/java/checks/UseFilterBeforeSort.java

@@ -0,0 +1,27 @@
+package org.greencodeinitiative.creedengo.java.checks;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+class UseFilterBeforeSort {
+    UseFilterBeforeSort() {
+    }
+
+    public void manipulateStream(final List<String> list) {
+        list.stream() // Noncompliant {{Use 'filter' before 'sorted' for better efficiency.}}
+                .sorted()
+                .filter(s -> s.startsWith("A"))
+                .collect(Collectors.toList());
+
+        list.stream() // Noncompliant {{Use 'filter' before 'sorted' for better efficiency.}}
+                .sorted()
+                .map(element -> element.toString())
+                .filter(s -> s.startsWith("A"))
+                .collect(Collectors.toList());
+
+        list.stream() // Compliant {{Use 'filter' before 'sorted' for better efficiency.}}
+                .filter(s -> s.startsWith("A"))
+                .sorted()
+                .collect(Collectors.toList());
+    }
+}

src/main/java/org/greencodeinitiative/creedengo/java/JavaCheckRegistrar.java

@@ -50,7 +50,8 @@ public class JavaCheckRegistrar implements CheckRegistrar {
             FreeResourcesOfAutoCloseableInterface.class,
             AvoidMultipleIfElseStatement.class,
             UseOptionalOrElseGetVsOrElse.class,
-            MakeNonReassignedVariablesConstants.class
+            MakeNonReassignedVariablesConstants.class,
+            UseFilterBeforeSort.class
     );
 
     /**

src/main/java/org/greencodeinitiative/creedengo/java/checks/UseFilterBeforeSort.java

@@ -0,0 +1,77 @@
+package org.greencodeinitiative.creedengo.java.checks;
+
+import org.sonar.check.Rule;
+import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
+import org.sonar.plugins.java.api.tree.*;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+@Rule(key = "GCI91")
+public class UseFilterBeforeSort extends IssuableSubscriptionVisitor {
+    @Override
+    public List<Tree.Kind> nodesToVisit() {
+        return Collections.singletonList(Tree.Kind.METHOD_INVOCATION);
+    }
+
+    @Override
+    public void visitNode(Tree tree) {
+        if (tree instanceof MethodInvocationTree) {
+            MethodInvocationTree mit = (MethodInvocationTree) tree;
+
+            if (!isTerminalOperation(mit)) {
+                return; // Ignoring intermediate steps (filter, sorted, etc.)
+            }
+
+            List<String> methodChain = extractChainedMethodNames(mit);
+
+            int sortedIndex = methodChain.indexOf("sorted");
+            int filterIndex = methodChain.indexOf("filter");
+
+            if (sortedIndex != -1 && filterIndex != -1 && sortedIndex < filterIndex) {
+                reportIssue(tree, "Use 'filter' before 'sorted' for better efficiency.");
+            }
+        }
+    }
+
+    private List<String> extractChainedMethodNames(MethodInvocationTree terminalInvocation) {
+        List<String> methodNames = new ArrayList<>();
+        ExpressionTree current = terminalInvocation;
+
+        while (current instanceof MethodInvocationTree) {
+            MethodInvocationTree methodCall = (MethodInvocationTree) current;
+            ExpressionTree methodSelect = methodCall.methodSelect();
+
+            if (methodSelect instanceof MemberSelectExpressionTree) {
+                MemberSelectExpressionTree memberSelect = (MemberSelectExpressionTree) methodSelect;
+                methodNames.add(memberSelect.identifier().name());
+                current = memberSelect.expression(); // Go to the previous method
+            } else {
+                break;
+            }
+        }
+
+        Collections.reverse(methodNames); // Reverse to get right order in collection like stream → ... → collect
+        return methodNames;
+    }
+
+    private boolean isTerminalOperation(MethodInvocationTree tree) {
+        if (!(tree.methodSelect() instanceof MemberSelectExpressionTree)) {
+            return false;
+        }
+        String methodName = ((MemberSelectExpressionTree) tree.methodSelect()).identifier().name();
+        // Ajouter ici tous les terminaux connus
+        return "collect".equals(methodName)
+                || "forEach".equals(methodName)
+                || "reduce".equals(methodName)
+                || "count".equals(methodName)
+                || "toArray".equals(methodName)
+                || "anyMatch".equals(methodName)
+                || "allMatch".equals(methodName)
+                || "noneMatch".equals(methodName)
+                || "findFirst".equals(methodName)
+                || "findAny".equals(methodName);
+    }
+
+}

src/main/resources/org/greencodeinitiative/creedengo/java/creedengo_way_profile.json

@@ -18,6 +18,7 @@
 	"GCI78",
 	"GCI79",
 	"GCI82",
+	"GCI91",
 	"GCI94"
   ]
 }

src/test/files/UseFilterBeforeSort.java

@@ -0,0 +1,44 @@
+/*
+ * creedengo - Java language - Provides rules to reduce the environmental footprint of your Java programs
+ * Copyright © 2024 Green Code Initiative (https://green-code-initiative.org/)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.greencodeinitiative.creedengo.java.checks;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+class UseFilterBeforeSort {
+    UseFilterBeforeSort() {
+    }
+
+    public void manipulateStream(List<String> list) {
+        list.stream() // Noncompliant {{Use 'filter' before 'sorted' for better efficiency.}}
+                .sorted()
+                .filter(s -> s.startsWith("A"))
+                .collect(Collectors.toList());
+
+        list.stream() // Noncompliant {{Use 'filter' before 'sorted' for better efficiency.}}
+                .sorted()
+                .otherMethod()
+                .filter(s -> s.startsWith("A"))
+                .collect(Collectors.toList());
+
+        list.stream() // Compliant {{Use 'filter' before 'sorted' for better efficiency.}}
+                .filter(s -> s.startsWith("A"))
+                .sorted()
+                .collect(Collectors.toList());
+    }
+}

src/test/java/org/greencodeinitiative/creedengo/java/checks/UseFilterBeforeSortTest.java

@@ -0,0 +1,14 @@
+package org.greencodeinitiative.creedengo.java.checks;
+
+import org.junit.jupiter.api.Test;
+import org.sonar.java.checks.verifier.CheckVerifier;
+
+public class UseFilterBeforeSortTest {
+    @Test
+    void testHasIssues() {
+        CheckVerifier.newVerifier()
+                .onFile("src/test/files/UseFilterBeforeSort.java")
+                .withCheck(new UseFilterBeforeSort())
+                .verifyIssues();
+    }
+}