Minor code improvement.

Author: afoucret

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/inference/InferenceRunner.java

@@ -26,10 +26,9 @@ public class InferenceRunner {
     private final Client client;
     private final ThreadPool threadPool;
 
-    public InferenceRunner(Client client) {
+    public InferenceRunner(Client client, ThreadPool threadPool) {
         this.client = client;
-        // TODO: revisit the executor service instantiation and thread pool choice.
-        this.threadPool = client.threadPool();
+        this.threadPool = threadPool;
     }
 
     public ThreadPool threadPool() {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plugin/TransportEsqlQueryAction.java

@@ -155,7 +155,7 @@ public TransportEsqlQueryAction(
             projectResolver,
             indexNameExpressionResolver,
             usageService,
-            new InferenceRunner(client)
+            new InferenceRunner(client, threadPool)
         );
 
         this.computeService = new ComputeService(

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/inference/InferenceRunnerTests.java

@@ -65,7 +65,7 @@ public void shutdownThreadPool() {
     }
 
     public void testResolveInferenceIds() throws Exception {
-        InferenceRunner inferenceRunner = new InferenceRunner(mockClient());
+        InferenceRunner inferenceRunner = new InferenceRunner(mockClient(), threadPool);
         List<InferencePlan<?>> inferencePlans = List.of(mockInferencePlan("rerank-plan"));
         SetOnce<InferenceResolution> inferenceResolutionSetOnce = new SetOnce<>();
 
@@ -82,7 +82,7 @@ public void testResolveInferenceIds() throws Exception {
     }
 
     public void testResolveMultipleInferenceIds() throws Exception {
-        InferenceRunner inferenceRunner = new InferenceRunner(mockClient());
+        InferenceRunner inferenceRunner = new InferenceRunner(mockClient(), threadPool);
         List<InferencePlan<?>> inferencePlans = List.of(
             mockInferencePlan("rerank-plan"),
             mockInferencePlan("rerank-plan"),
@@ -110,7 +110,7 @@ public void testResolveMultipleInferenceIds() throws Exception {
     }
 
     public void testResolveMissingInferenceIds() throws Exception {
-        InferenceRunner inferenceRunner = new InferenceRunner(mockClient());
+        InferenceRunner inferenceRunner = new InferenceRunner(mockClient(), threadPool);
         List<InferencePlan<?>> inferencePlans = List.of(mockInferencePlan("missing-plan"));
 
         SetOnce<InferenceResolution> inferenceResolutionSetOnce = new SetOnce<>();
@@ -132,7 +132,6 @@ public void testResolveMissingInferenceIds() throws Exception {
     @SuppressWarnings({ "unchecked", "raw-types" })
     private Client mockClient() {
         Client client = mock(Client.class);
-        when(client.threadPool()).thenReturn(threadPool);
         doAnswer(i -> {
             Runnable sendResponse = () -> {
                 GetInferenceModelAction.Request request = i.getArgument(1, GetInferenceModelAction.Request.class);