How to Implement Retry for JUnit Tests (#18527)

* feat: added test codes

Signed-off-by: Emmanuel Mireku Omari <[email protected]>

* fix: added indentation to dependancies

Signed-off-by: Emmanuel Mireku Omari <[email protected]>

* fix: used 4-space indentation instead of tabs

Signed-off-by: Emmanuel Mireku Omari <[email protected]>

* fix: updated module and indents

Signed-off-by: Emmanuel Mireku Omari <[email protected]>

---------

Signed-off-by: Emmanuel Mireku Omari <[email protected]>

Author: 3ga01

testing-modules/junit-5-advanced-2/pom.xml

@@ -33,6 +33,26 @@
             <version>${system-lambda.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>5.10.0</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.10.0</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit-pioneer</groupId>
+            <artifactId>junit-pioneer</artifactId>
+            <version>2.0.1</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -61,4 +81,4 @@
         <system-lambda.version>1.2.1</system-lambda.version>
     </properties>
 
-</project>
+</project>

testing-modules/junit-5-advanced-2/src/test/java/com/baeldung/retryjunit/RetryExtension.java

@@ -0,0 +1,27 @@
+package com.baeldung.retryjunit;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ExtensionContext.Store;
+import org.junit.jupiter.api.extension.TestExecutionExceptionHandler;
+
+public class RetryExtension implements TestExecutionExceptionHandler {
+    private static final int MAX_RETRIES = 3;
+    private static final ExtensionContext.Namespace NAMESPACE =
+            ExtensionContext.Namespace.create("RetryExtension");
+
+    @Override
+    public void handleTestExecutionException(ExtensionContext context, Throwable throwable)
+            throws Throwable {
+        Store store = context.getStore(NAMESPACE);
+        int retries = store.getOrDefault("retries", Integer.class, 0);
+
+        if (retries < MAX_RETRIES) {
+            retries++;
+            store.put("retries", retries);
+            System.out.println("Retrying test " + context.getDisplayName() + ", attempt " + retries);
+            throw throwable;
+        } else {
+            throw throwable;
+        }
+    }
+}

testing-modules/junit-5-advanced-2/src/test/java/com/baeldung/retryjunit/RetryPioneerTest.java

@@ -0,0 +1,16 @@
+package com.baeldung.retryjunit;
+
+import org.junitpioneer.jupiter.RetryingTest;
+
+public class RetryPioneerTest {
+    private static int attempt = 0;
+
+    @RetryingTest(maxAttempts = 3)
+    void testWithRetry() {
+        attempt++;
+        System.out.println("Test attempt: " + attempt);
+        if (attempt < 3) {
+            throw new RuntimeException("Failing test");
+        }
+    }
+}

testing-modules/junit-5-advanced-2/src/test/java/com/baeldung/retryjunit/RetryRule.java

@@ -0,0 +1,33 @@
+package com.baeldung.retryjunit;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+public class RetryRule implements TestRule {
+    private final int retryCount;
+
+    public RetryRule(int retryCount) {
+        this.retryCount = retryCount;
+    }
+
+    @Override
+    public Statement apply(Statement base, Description description) {
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                Throwable failure = null;
+                for (int i = 0; i < retryCount; i++) {
+                    try {
+                        base.evaluate();
+                        return;
+                    } catch (Throwable t) {
+                        failure = t;
+                        System.out.println("Retry " + (i + 1) + "/" + retryCount + " for test " + description.getDisplayName());
+                    }
+                }
+                throw failure;
+            }
+        };
+    }
+}

testing-modules/junit-5-advanced-2/src/test/java/com/baeldung/retryjunit/RetryTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.retryjunit;
+
+import org.junit.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+@ExtendWith(RetryExtension.class)
+public class RetryTest {
+    private static int attempt = 0;
+
+    @Test
+    public void testWithRetry() {
+        attempt++;
+        System.out.println("Test attempt: " + attempt);
+        if (attempt < 3) {
+            throw new RuntimeException("Failing test");
+        }
+    }
+}

testing-modules/junit-5-advanced-2/src/test/java/com/baeldung/retryjunit/RetryTestJUnit4.java

@@ -0,0 +1,19 @@
+package com.baeldung.retryjunit;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+public class RetryTestJUnit4 {
+    @Rule
+    public RetryRule retryRule = new RetryRule(3);
+    private static int attempt = 0;
+
+    @Test
+    public void testWithRetry() {
+        attempt++;
+        System.out.println("Test attempt: " + attempt);
+        if (attempt < 3) {
+            throw new RuntimeException("Failing test");
+        }
+    }
+}