chore: Added/updated unit tests to validate code

.github/workflows/maven.yml → .github/workflows/build.yml

@@ -30,9 +30,9 @@ jobs:
           distribution: temurin
           cache: maven
       - name: Check formatting
-        run: ./mvnw --batch-mode fmt:check
-      - name: Build
-        run: ./mvnw --batch-mode package
+        run: ./mvnw -B fmt:check
+      - name: Build and verify
+        run: ./mvnw -B verify
       - name: Update dependency graph
         if: github.event_name == 'push' && github.ref == 'refs/heads/master'
         uses: advanced-security/maven-dependency-submission-action@b275d12641ac2d2108b2cbb7598b154ad2f2cee8 # v5.0.0

RELEASING.md

@@ -91,7 +91,7 @@ It usually appears immediately after the release process is done, but can take a
 ## Docker images
 
 As part of the release process, `./mvnw` will create the git tag.
-This tag is picked up by [GitHub Actions](https://github.com/prometheus/cloudwatch_exporter/actions/workflows/maven.yml), which builds and pushes the [Docker images](README.md#docker-images).
+This tag is picked up by [GitHub Actions](https://github.com/prometheus/cloudwatch_exporter/actions/workflows/build.yml), which builds and pushes the [Docker images](README.md#docker-images).
 
 ## GitHub Release
 

pom.xml

@@ -29,7 +29,7 @@
   <licenses>
     <license>
       <name>The Apache Software License, Version 2.0</name>
-      <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
+      <url>https://www.apache.org/licenses/LICENSE-2.0.txt</url>
       <distribution>repo</distribution>
     </license>
   </licenses>
@@ -50,11 +50,13 @@
     <project.releaseDate>${maven.build.timestamp}</project.releaseDate>
     <maven.compiler.release>17</maven.compiler.release>
     <!-- Dependency versions -->
+    <assertj.version>3.27.7</assertj.version>
     <caffeine.version>3.2.4</caffeine.version>
     <commons-codec.version>1.22.0</commons-codec.version>
     <hamcrest.version>3.0</hamcrest.version>
     <io.prometheus.version>0.16.0</io.prometheus.version>
-    <junit.version>4.13.2</junit.version>
+    <jetty.version>12.1.10</jetty.version>
+    <junit.jupiter.version>6.1.0</junit.jupiter.version>
     <mockito.version>5.23.0</mockito.version>
     <slf4j.version>2.0.18</slf4j.version>
     <snakeyaml.version>2.6</snakeyaml.version>
@@ -72,6 +74,8 @@
     <maven-source-plugin.version>3.4.0</maven-source-plugin.version>
     <maven-surefire-plugin.version>3.5.6</maven-surefire-plugin.version>
     <versions-maven-plugin.version>2.21.0</versions-maven-plugin.version>
+    <jacoco-maven-plugin.version>0.8.14</jacoco-maven-plugin.version>
+
   </properties>
   <dependencies>
 
@@ -123,12 +127,12 @@
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-server</artifactId>
-      <version>12.0.36</version>
+      <version>${jetty.version}</version>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty.ee10</groupId>
       <artifactId>jetty-ee10-servlet</artifactId>
-      <version>12.0.36</version>
+      <version>${jetty.version}</version>
     </dependency>
     <dependency>
       <groupId>com.github.ben-manes.caffeine</groupId>
@@ -137,9 +141,15 @@
     </dependency>
 
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>${junit.version}</version>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>${junit.jupiter.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.assertj</groupId>
+      <artifactId>assertj-core</artifactId>
+      <version>${assertj.version}</version>
       <scope>test</scope>
     </dependency>
     <dependency>
@@ -246,9 +256,31 @@
         <artifactId>maven-surefire-plugin</artifactId>
         <version>${maven-surefire-plugin.version}</version>
         <configuration>
-          <argLine>-javaagent:${settings.localRepository}/org/mockito/mockito-core/5.23.0/mockito-core-5.23.0.jar -XX:+EnableDynamicAgentLoading -Djdk.net.URLClassPath.disableClassPathURLCheck=true</argLine>
+          <useModulePath>false</useModulePath>
+          <argLine>-javaagent:${settings.localRepository}/org/mockito/mockito-core/${mockito.version}/mockito-core-${mockito.version}.jar @{argLine} -XX:+EnableDynamicAgentLoading -Djdk.net.URLClassPath.disableClassPathURLCheck=true</argLine>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>org.jacoco</groupId>
+        <artifactId>jacoco-maven-plugin</artifactId>
+        <version>${jacoco-maven-plugin.version}</version>
+        <executions>
+          <execution>
+            <id>jacoco-prepare-agent</id>
+            <phase>process-test-classes</phase>
+            <goals>
+              <goal>prepare-agent</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>jacoco-report</id>
+            <phase>verify</phase>
+            <goals>
+              <goal>report</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-javadoc-plugin</artifactId>
@@ -367,4 +399,4 @@
       </build>
     </profile>
   </profiles>
-</project>
+</project>

scripts/stress-test.sh

@@ -0,0 +1,106 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) The Prometheus Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+readonly SCRIPT_DIR
+readonly PROJECT_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
+readonly MVNW="${PROJECT_DIR}/mvnw"
+
+readonly LOG_FILE="stress-test.log"
+
+usage() {
+    cat <<'EOF'
+Usage: ./scripts/stress-test.sh <number-of-iterations>
+
+Run CloudWatch Exporter tests multiple times to check for flaky tests.
+
+Arguments:
+  <number-of-iterations>    Number of times to run the test suite.
+
+Examples:
+  ./scripts/stress-test.sh 5
+  ./scripts/stress-test.sh 10
+EOF
+}
+
+log() {
+    echo "[INFO] $*" | tee -a "${LOG_FILE}"
+}
+
+fail() {
+    echo "[ERROR] $*" | tee -a "${LOG_FILE}" >&2
+    exit 1
+}
+
+main() {
+    local iterations iteration start_time end_time elapsed_time total_elapsed
+
+    if [[ $# -ne 1 ]]; then
+        usage
+        exit 1
+    fi
+
+    iterations="$1"
+
+    [[ -x "${MVNW}" ]] || fail "mvnw not found or not executable: ${MVNW}"
+
+    if [[ ! "${iterations}" =~ ^[1-9][0-9]*$ ]]; then
+        fail "Invalid iterations '${iterations}'. Must be a positive integer."
+    fi
+
+    rm -f "${LOG_FILE}"
+
+    log "Starting stress test with ${iterations} iteration(s)"
+    log ""
+
+    log "Building project (initial build)..."
+    local build_start
+    build_start="${SECONDS}"
+    if ! (cd "${PROJECT_DIR}" && ./mvnw -B compile -DskipTests) |& tee -a "${LOG_FILE}"; then
+        fail "Initial build failed. See ${LOG_FILE} for details."
+    fi
+    local build_elapsed
+    build_elapsed=$((SECONDS - build_start))
+    log "Initial build completed in ${build_elapsed}s"
+    log ""
+
+    log "Running ${iterations} test iteration(s)..."
+    log ""
+
+    for ((iteration = 1; iteration <= iterations; iteration++)); do
+        start_time="${SECONDS}"
+        log "Iteration ${iteration}/${iterations} started"
+
+        if ! (cd "${PROJECT_DIR}" && ./mvnw -B test) |& tee -a "${LOG_FILE}"; then
+            end_time="${SECONDS}"
+            elapsed_time=$((end_time - start_time))
+            fail "Iteration ${iteration}/${iterations} failed after ${elapsed_time}s. See ${LOG_FILE} for details."
+        fi
+
+        end_time="${SECONDS}"
+        elapsed_time=$((end_time - start_time))
+        log "Iteration ${iteration}/${iterations} passed (${elapsed_time}s)"
+        log ""
+    done
+
+    total_elapsed="${SECONDS}"
+
+    log "All ${iterations} iteration(s) completed successfully in ${total_elapsed}s"
+}
+
+main "$@"

src/main/java/io/prometheus/cloudwatch/CloudWatchCollector.java

@@ -112,6 +112,7 @@ public CloudWatchCollector(String yamlConfig) {
   }
 
   /* For unittests. */
+  @SuppressWarnings("unchecked")
   protected CloudWatchCollector(
       String jsonConfig,
       CloudWatchClient cloudWatchClient,
@@ -141,6 +142,7 @@ protected void reloadConfig() throws IOException {
     }
   }
 
+  @SuppressWarnings("unchecked")
   protected void loadConfig(
       Reader in, CloudWatchClient cloudWatchClient, ResourceGroupsTaggingApiClient taggingClient) {
     loadConfig(
@@ -149,6 +151,7 @@ protected void loadConfig(
         taggingClient);
   }
 
+  @SuppressWarnings("unchecked")
   private void loadConfig(
       Map<String, Object> config,
       CloudWatchClient cloudWatchClient,

src/test/java/io/prometheus/cloudwatch/CachingDimensionExpiryTest.java

@@ -1,14 +1,14 @@
 package io.prometheus.cloudwatch;
 
-import static org.junit.Assert.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
 
 import io.prometheus.cloudwatch.CachingDimensionSource.DimensionCacheKey;
 import io.prometheus.cloudwatch.CachingDimensionSource.DimensionExpiry;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Collections;
 import java.util.List;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class CachingDimensionExpiryTest {
 
@@ -27,7 +27,7 @@ public void expireAfterCreateUsesDefaultWithEmptyOverrides() {
             emptyData,
             Instant.now().toEpochMilli());
 
-    assertEquals(35, Duration.ofNanos(afterCreate).toSeconds());
+    assertThat(Duration.ofNanos(afterCreate).toSeconds()).isEqualTo(35);
   }
 
   @Test
@@ -42,7 +42,7 @@ public void expireAfterCreateUsesMetricLevelOverride() {
             emptyData,
             Instant.now().toEpochMilli());
 
-    assertEquals(100, Duration.ofNanos(afterCreate).toSeconds());
+    assertThat(Duration.ofNanos(afterCreate).toSeconds()).isEqualTo(100);
   }
 
   @Test
@@ -57,7 +57,7 @@ public void expireAfterCreateUsesDefaultIfNoMatchedOverride() {
             emptyData,
             Instant.now().toEpochMilli());
 
-    assertEquals(35, Duration.ofNanos(afterCreate).toSeconds());
+    assertThat(Duration.ofNanos(afterCreate).toSeconds()).isEqualTo(35);
   }
 
   @Test
@@ -73,7 +73,7 @@ public void expireAfterUpdateUsesCurrentDuration() {
             Instant.now().toEpochMilli(),
             10_000_000);
 
-    assertEquals(10_000_000, afterUpdate);
+    assertThat(afterUpdate).isEqualTo(10_000_000);
   }
 
   @Test
@@ -88,7 +88,30 @@ public void expireAfterReadUsesCurrentDuration() {
             emptyData,
             Instant.now().toEpochMilli(),
             20_000_000);
-    assertEquals(20_000_000, afterRead);
+    assertThat(afterRead).isEqualTo(20_000_000);
+  }
+
+  @Test
+  public void dimensionCacheKeyEqualsHandlesIdentityNullDifferentTypesAndFields() {
+    DimensionCacheKey key = createDimensionCacheKey("AWS/S3", "BucketSizeBytes", 100);
+    DimensionCacheKey same = createDimensionCacheKey("AWS/S3", "BucketSizeBytes", 100);
+    DimensionCacheKey differentRule = createDimensionCacheKey("AWS/EC2", "CPUUtilization", 100);
+    DimensionCacheKey differentTags =
+        new DimensionCacheKey(
+            createMetricRule("AWS/S3", "BucketSizeBytes", 100), List.of("bucket-a"));
+
+    assertThat(key).isEqualTo(key);
+    assertThat(key).isEqualTo(same);
+    assertThat(key).isNotEqualTo(null);
+    assertThat(key).isNotEqualTo("not a key");
+    assertThat(key).isNotEqualTo(differentRule);
+    assertThat(key).isNotEqualTo(differentTags);
+    assertThat(key.hashCode()).isEqualTo(same.hashCode());
+  }
+
+  @Test
+  public void dimensionCacheKeyHashCodeHandlesNullFields() {
+    assertThat(new DimensionCacheKey(null, null).hashCode()).isZero();
   }
 
   private DimensionCacheKey createDimensionCacheKey(

src/test/java/io/prometheus/cloudwatch/CachingDimensionSourceTest.java

@@ -1,13 +1,13 @@
 package io.prometheus.cloudwatch;
 
 import static io.prometheus.cloudwatch.DimensionSource.DimensionData;
-import static org.junit.Assert.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
 
 import io.prometheus.cloudwatch.CachingDimensionSource.DimensionCacheConfig;
 import java.time.Duration;
 import java.util.Collections;
 import java.util.List;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import software.amazon.awssdk.services.cloudwatch.model.Dimension;
 
 public class CachingDimensionSourceTest {
@@ -24,8 +24,8 @@ public void cachedFromDelegate() {
         sut.getDimensions(createMetricRule("AWS/Redshift", "WriteIOPS"), Collections.emptyList());
 
     Dimension dimension = Dimension.builder().name("AWS/Redshift").value("WriteIOPS").build();
-    assertEquals(1, source.called);
-    assertEquals(dimension, expected.getDimensions().get(0).get(0));
+    assertThat(source.called).isEqualTo(1);
+    assertThat(expected.getDimensions().get(0).get(0)).isEqualTo(dimension);
   }
 
   private MetricRule createMetricRule(String namespace, String name) {