Add a test for index providers giving data stream mode

Author: dakrone

modules/data-streams/src/test/java/org/elasticsearch/datastreams/action/TransportGetDataStreamsActionTests.java

@@ -18,12 +18,15 @@
 import org.elasticsearch.cluster.metadata.DataStreamTestHelper;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.Metadata;
+import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.ClusterSettings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.core.Tuple;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexMode;
 import org.elasticsearch.index.IndexNotFoundException;
+import org.elasticsearch.index.IndexSettingProvider;
 import org.elasticsearch.index.IndexSettingProviders;
 import org.elasticsearch.indices.SystemIndices;
 import org.elasticsearch.indices.TestIndexNameExpressionResolver;
@@ -483,4 +486,58 @@ public void testDataStreamIsFailureStoreEffectivelyEnabled_enabledByClusterSetti
         assertThat(response.getDataStreams(), hasSize(1));
         assertThat(response.getDataStreams().getFirst().isFailureStoreEffectivelyEnabled(), is(true));
     }
+
+    public void testProvidersAffectMode() {
+        ClusterState state;
+        {
+            var mBuilder = new Metadata.Builder();
+            DataStreamTestHelper.getClusterStateWithDataStreams(
+                mBuilder,
+                List.of(Tuple.tuple("data-stream-1", 2)),
+                List.of(),
+                System.currentTimeMillis(),
+                Settings.EMPTY,
+                0,
+                false,
+                false
+            );
+            state = ClusterState.builder(new ClusterName("_name")).metadata(mBuilder).build();
+        }
+
+        var req = new GetDataStreamAction.Request(TEST_REQUEST_TIMEOUT, new String[] {});
+        var response = TransportGetDataStreamsAction.innerOperation(
+            state,
+            req,
+            resolver,
+            systemIndices,
+            ClusterSettings.createBuiltInClusterSettings(),
+            dataStreamGlobalRetentionSettings,
+            emptyDataStreamFailureStoreSettings,
+            new IndexSettingProviders(
+                Set.of(
+                    (
+                        indexName,
+                        dataStreamName,
+                        templateIndexMode,
+                        metadata,
+                        resolvedAt,
+                        indexTemplateAndCreateRequestSettings,
+                        combinedTemplateMappings) -> Settings.builder().put("index.mode", IndexMode.LOOKUP).build()
+                )
+            ),
+            null
+        );
+        assertThat(response.getDataStreams().getFirst().getIndexModeName(), equalTo("lookup"));
+        assertThat(
+            response.getDataStreams()
+                .getFirst()
+                .getIndexSettingsValues()
+                .values()
+                .stream()
+                .findFirst()
+                .map(GetDataStreamAction.Response.IndexProperties::indexMode)
+                .orElse("bad"),
+            equalTo("standard")
+        );
+    }
 }

server/src/main/java/org/elasticsearch/action/datastreams/GetDataStreamAction.java

@@ -337,6 +337,11 @@ public Long getMaximumTimestamp() {
                 return maximumTimestamp;
             }
 
+            @Nullable
+            public String getIndexModeName() {
+                return indexMode;
+            }
+
             @Override
             public void writeTo(StreamOutput out) throws IOException {
                 dataStream.writeTo(out);