Provide list of supported Kafka versions to users (#180)

Signed-off-by: see-quick <[email protected]>

Author: see-quick

src/main/java/io/strimzi/test/container/KafkaVersionService.java

@@ -188,6 +188,18 @@ public String toString() {
         }
     }
 
+    /**
+     * Get list of all supported Kafka versions.
+     *
+     * @return list of supported Kafka version strings, sorted from oldest to newest
+     */
+    public List<String> getSupportedKafkaVersions() {
+        return this.logicalKafkaVersionEntities.stream()
+            .sorted()
+            .map(KafkaVersion::getVersion)
+            .collect(Collectors.toList());
+    }
+
     /**
      * Get the latest release where the result is intentionally not deterministic.
      * It's the released test-container-images image with the highest Kafka version number.

src/main/java/io/strimzi/test/container/StrimziKafkaCluster.java

@@ -18,6 +18,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.ExecutionException;
@@ -905,6 +906,15 @@ public boolean isUsingDedicatedRoles() {
         return this.useDedicatedRoles;
     }
 
+    /**
+     * Get list of all supported Kafka versions.
+     *
+     * @return list of supported Kafka version strings, sorted from oldest to newest
+     */
+    public static List<String> getSupportedKafkaVersions() {
+        return KafkaVersionService.getInstance().getSupportedKafkaVersions();
+    }
+
     /**
      * Retrieves the Proxy instance for a specific node by its node ID.
      * Works for both brokers and controllers.

src/test/java/io/strimzi/test/container/KafkaVersionServiceTest.java

@@ -7,6 +7,8 @@
 import org.hamcrest.CoreMatchers;
 import org.junit.jupiter.api.Test;
 
+import java.util.List;
+
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -79,4 +81,34 @@ void testExtractVersionFromImageNameAdditionalSuffix() {
         Exception exception = assertThrows(IllegalArgumentException.class, () -> KafkaVersionService.KafkaVersion.extractVersionFromImageName(imageName));
         assertThat(exception.getMessage(), CoreMatchers.containsString("Cannot extract Kafka version from image name"));
     }
+
+    @Test
+    void testGetSupportedKafkaVersionsReturnsNonEmptyList() {
+        List<String> versions = KafkaVersionService.getInstance().getSupportedKafkaVersions();
+
+        assertThat(versions, CoreMatchers.notNullValue());
+        assertThat(versions.isEmpty(), CoreMatchers.is(false));
+    }
+
+    @Test
+    void testGetSupportedKafkaVersionsAreSorted() {
+        List<String> versions = KafkaVersionService.getInstance().getSupportedKafkaVersions();
+
+        for (int i = 0; i < versions.size() - 1; i++) {
+            String current = versions.get(i);
+            String next = versions.get(i + 1);
+            int comparison = KafkaVersionService.KafkaVersion.compareVersions(current, next);
+            assertThat("Versions should be sorted: " + current + " should be <= " + next,
+                comparison <= 0, CoreMatchers.is(true));
+        }
+    }
+
+    @Test
+    void testGetSupportedKafkaVersionsContainsLatestRelease() {
+        List<String> versions = KafkaVersionService.getInstance().getSupportedKafkaVersions();
+        String latestVersion = KafkaVersionService.getInstance().latestRelease().getVersion();
+
+        assertThat("Supported versions should contain the latest release",
+            versions.contains(latestVersion), CoreMatchers.is(true));
+    }
 }

src/test/java/io/strimzi/test/container/StrimziKafkaClusterTest.java

@@ -1035,4 +1035,35 @@ void testDedicatedRolesClusterWithLogFilePathAppliesToControllers() {
                 container.getLogFilePath(), is("target/controller-logs/"));
         }
     }
+
+    @Test
+    void testGetSupportedKafkaVersionsReturnsNonEmptyList() {
+        List<String> versions = StrimziKafkaCluster.getSupportedKafkaVersions();
+
+        assertThat(versions, is(CoreMatchers.notNullValue()));
+        assertThat(versions.isEmpty(), is(false));
+    }
+
+    @Test
+    void testGetSupportedKafkaVersionsAreSorted() {
+        List<String> versions = StrimziKafkaCluster.getSupportedKafkaVersions();
+
+        for (int i = 0; i < versions.size() - 1; i++) {
+            String current = versions.get(i);
+            String next = versions.get(i + 1);
+            int comparison = KafkaVersionService.KafkaVersion.compareVersions(current, next);
+            assertThat("Versions should be sorted: " + current + " should be <= " + next,
+                comparison <= 0, is(true));
+        }
+    }
+
+    @Test
+    void testGetSupportedKafkaVersionsContainsValidVersionFormat() {
+        List<String> versions = StrimziKafkaCluster.getSupportedKafkaVersions();
+
+        for (String version : versions) {
+            assertThat("Version should match X.Y.Z format: " + version,
+                version.matches("\\d+\\.\\d+\\.\\d+"), is(true));
+        }
+    }
 }