feat(GCI116): add rule to avoid range(len()) pattern

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - [#146](https://github.com/green-code-initiative/creedengo-python/pull/146) Add rule GCI24: Returned SQL results should be limited (avoid SELECT...FROM without LIMIT)
+- Add rule GCI116: Avoid range(len()) pattern, prefer direct iteration or enumerate()
 
 ### Changed
 

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

@@ -548,6 +548,28 @@ void testGCI203_compliant() {
         checkIssuesForFile(filePath, ruleId, ruleMsg, startLines, endLines, SEVERITY, TYPE, EFFORT_1H);
     }
 
+    @Test
+    void testGCI116_compliant() {
+        String filePath = "src/GCI116/preferEnumerateOverRangeLenCompliant.py";
+        String ruleId = "creedengo-python:GCI116";
+        String ruleMsg = "Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access";
+        int[] startLines = new int[]{};
+        int[] endLines = new int[]{};
+
+        checkIssuesForFile(filePath, ruleId, ruleMsg, startLines, endLines, SEVERITY, TYPE, EFFORT_5MIN);
+    }
+
+    @Test
+    void testGCI116_nonCompliant() {
+        String filePath = "src/GCI116/preferEnumerateOverRangeLenNonCompliant.py";
+        String ruleId = "creedengo-python:GCI116";
+        String ruleMsg = "Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access";
+        int[] startLines = new int[]{3, 7, 12, 16, 20, 21, 24, 26, 28};
+        int[] endLines = new int[]{3, 7, 12, 16, 20, 21, 24, 26, 28};
+
+        checkIssuesForFile(filePath, ruleId, ruleMsg, startLines, endLines, SEVERITY, TYPE, EFFORT_5MIN);
+    }
+
     @Test
     void testGCI404() {
         String filePath = "src/GCI404/avoidListComprehensionInIterations.py";

src/it/test-projects/creedengo-python-plugin-test-project/src/GCI116/preferEnumerateOverRangeLen.py

@@ -0,0 +1,58 @@
+my_list = [1, 2, 3, 4, 5]
+
+for i in range(len(my_list)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    print(i, my_list[i])
+
+names = ["Alice", "Bob", "Charlie"]
+for i in range(len(names)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    print(names[i])
+
+data = {"a": 1, "b": 2}
+keys = list(data.keys())
+for i in range(len(keys)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    print(keys[i])
+
+def process(items):
+    for i in range(len(items)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+        items[i] = items[i] * 2
+
+matrix = [[1, 2], [3, 4]]
+for i in range(len(matrix)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    for j in range(len(matrix[i])):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+        print(matrix[i][j])
+
+for i, val in enumerate(my_list):
+    print(i, val)
+
+for i in range(10):
+    print(i)
+
+n = 10
+for i in range(n):
+    print(i)
+
+for i in range(0, len(my_list)):
+    print(i)
+
+for i in range(0, len(my_list), 2):
+    print(i)
+
+for item in my_list:
+    print(item)
+
+length = len(my_list)
+for i in range(length):
+    print(i)
+
+result = [my_list[i] for i in range(len(my_list))]  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+
+squared = {i: my_list[i]**2 for i in range(len(my_list))}  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+
+gen = sum(my_list[i] for i in range(len(my_list)))  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+
+compliant_comp = [val for val in my_list]
+
+compliant_enum = [val for i, val in enumerate(my_list)]
+
+compliant_range = [i for i in range(10)]
+

src/it/test-projects/creedengo-python-plugin-test-project/src/GCI116/preferEnumerateOverRangeLenCompliant.py

@@ -0,0 +1,30 @@
+my_list = [1, 2, 3, 4, 5]
+
+for i, val in enumerate(my_list):
+    print(i, val)
+
+for i in range(10):
+    print(i)
+
+n = 10
+for i in range(n):
+    print(i)
+
+for i in range(0, len(my_list)):
+    print(i)
+
+for i in range(0, len(my_list), 2):
+    print(i)
+
+for item in my_list:
+    print(item)
+
+length = len(my_list)
+for i in range(length):
+    print(i)
+
+compliant_comp = [val for val in my_list]
+
+compliant_enum = [val for i, val in enumerate(my_list)]
+
+compliant_range = [i for i in range(10)]

src/it/test-projects/creedengo-python-plugin-test-project/src/GCI116/preferEnumerateOverRangeLenNonCompliant.py

@@ -0,0 +1,29 @@
+my_list = [1, 2, 3, 4, 5]
+
+for i in range(len(my_list)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    print(i, my_list[i])
+
+names = ["Alice", "Bob", "Charlie"]
+for i in range(len(names)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    print(names[i])
+
+data = {"a": 1, "b": 2}
+keys = list(data.keys())
+for i in range(len(keys)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    print(keys[i])
+
+def process(items):
+    for i in range(len(items)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+        items[i] = items[i] * 2
+
+matrix = [[1, 2], [3, 4]]
+for i in range(len(matrix)):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+    for j in range(len(matrix[i])):  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+        print(matrix[i][j])
+
+result = [my_list[i] for i in range(len(my_list))]  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+
+squared = {i: my_list[i]**2 for i in range(len(my_list))}  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+
+gen = sum(my_list[i] for i in range(len(my_list)))  # Noncompliant {{Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access}}
+

src/main/java/org/greencodeinitiative/creedengo/python/PythonRuleRepository.java

@@ -56,7 +56,8 @@ public record PythonRuleRepository(SonarRuntime sonarRuntime) implements RulesDe
             GCI104AvoidCreatingTensorUsingNumpyOrNativePython.class,
             GCI110AvoidWildcardImportsCheck.class,
             GCI109AvoidExceptionsForControlFlowCheck.class,
-            GCI112UsingSlotsOnDataClasses.class
+            GCI112UsingSlotsOnDataClasses.class,
+            GCI116PreferEnumerateOverRangeLen.class
     );
 
     public static final String LANGUAGE = "py";

src/main/java/org/greencodeinitiative/creedengo/python/checks/GCI116PreferEnumerateOverRangeLen.java

@@ -0,0 +1,109 @@
+/*
+ * creedengo - Python language - Provides rules to reduce the environmental footprint of your Python 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.python.checks;
+
+import org.sonar.check.Rule;
+import org.sonar.plugins.python.api.PythonSubscriptionCheck;
+import org.sonar.plugins.python.api.SubscriptionContext;
+import org.sonar.plugins.python.api.tree.CallExpression;
+import org.sonar.plugins.python.api.tree.ComprehensionFor;
+import org.sonar.plugins.python.api.tree.Expression;
+import org.sonar.plugins.python.api.tree.ForStatement;
+import org.sonar.plugins.python.api.tree.Name;
+import org.sonar.plugins.python.api.tree.RegularArgument;
+import org.sonar.plugins.python.api.tree.Tree;
+
+import java.util.List;
+
+@Rule(key = "GCI116")
+public class GCI116PreferEnumerateOverRangeLen extends PythonSubscriptionCheck {
+
+    public static final String DESCRIPTION = "Avoid range(len()) pattern, prefer direct iteration or enumerate() which avoids costly index-based access";
+
+    @Override
+    public void initialize(Context context) {
+        context.registerSyntaxNodeConsumer(Tree.Kind.FOR_STMT, this::visitForStatement);
+        context.registerSyntaxNodeConsumer(Tree.Kind.COMP_FOR, this::visitComprehensionFor);
+    }
+
+    private void visitForStatement(SubscriptionContext context) {
+        ForStatement forStatement = (ForStatement) context.syntaxNode();
+
+        List<Expression> testExpressions = forStatement.testExpressions();
+        if (testExpressions.size() != 1) {
+            return;
+        }
+
+        Expression iterable = testExpressions.get(0);
+        if (isRangeLenCall(iterable)) {
+            context.addIssue(iterable, DESCRIPTION);
+        }
+    }
+
+    private void visitComprehensionFor(SubscriptionContext context) {
+        ComprehensionFor compFor = (ComprehensionFor) context.syntaxNode();
+        Expression iterable = compFor.iterable();
+        if (isRangeLenCall(iterable)) {
+            context.addIssue(iterable, DESCRIPTION);
+        }
+    }
+
+    private boolean isRangeLenCall(Expression expression) {
+        if (!expression.is(Tree.Kind.CALL_EXPR)) {
+            return false;
+        }
+
+        CallExpression callExpression = (CallExpression) expression;
+        Expression callee = callExpression.callee();
+
+        if (!callee.is(Tree.Kind.NAME)) {
+            return false;
+        }
+
+        if (!"range".equals(((Name) callee).name())) {
+            return false;
+        }
+
+        List<org.sonar.plugins.python.api.tree.Argument> arguments = callExpression.arguments();
+        if (arguments.size() != 1) {
+            return false;
+        }
+
+        org.sonar.plugins.python.api.tree.Argument firstArg = arguments.get(0);
+        if (!(firstArg instanceof RegularArgument)) {
+            return false;
+        }
+
+        return isLenCall(((RegularArgument) firstArg).expression());
+    }
+
+    private boolean isLenCall(Expression expression) {
+        if (!expression.is(Tree.Kind.CALL_EXPR)) {
+            return false;
+        }
+
+        CallExpression callExpression = (CallExpression) expression;
+        Expression callee = callExpression.callee();
+
+        if (!callee.is(Tree.Kind.NAME)) {
+            return false;
+        }
+
+        return "len".equals(((Name) callee).name());
+    }
+}

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

@@ -27,6 +27,7 @@
 		"GCI110",
 		"GCI111",
 		"GCI112",
+		"GCI116",
 		"GCI203",
 		"GCI404"
   ]

src/test/java/org/greencodeinitiative/creedengo/python/checks/GCI116PreferEnumerateOverRangeLenTest.java

@@ -0,0 +1,40 @@
+/*
+ * creedengo - Python language - Provides rules to reduce the environmental footprint of your Python 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.python.checks;
+
+import org.junit.jupiter.api.Test;
+import org.sonar.python.checks.utils.PythonCheckVerifier;
+
+class GCI116PreferEnumerateOverRangeLenTest {
+
+    @Test
+    void testNonCompliant() {
+        PythonCheckVerifier.verify(System.getProperty("testfiles.path") + "/GCI116/preferEnumerateOverRangeLen.py", new GCI116PreferEnumerateOverRangeLen());
+    }
+
+    @Test
+    void testNonCompliantOnly() {
+        PythonCheckVerifier.verify(System.getProperty("testfiles.path") + "/GCI116/preferEnumerateOverRangeLenNonCompliant.py", new GCI116PreferEnumerateOverRangeLen());
+    }
+
+    @Test
+    void testCompliant() {
+        PythonCheckVerifier.verifyNoIssue(System.getProperty("testfiles.path") + "/GCI116/preferEnumerateOverRangeLenCompliant.py", new GCI116PreferEnumerateOverRangeLen());
+    }
+}
+