feat: expose initial config load future for sub-classes of the BaseEppoClient (#48)

Author: typotter

README.md

@@ -10,7 +10,7 @@ or [JVM](https://github.com/Eppo-exp/java-server-sdk) SDKs.
 
 ```groovy
 dependencies {
-  implementation 'cloud.eppo:sdk-common-jvm:3.3.1'
+  implementation 'cloud.eppo:sdk-common-jvm:3.3.2'
 }
 ```
 

build.gradle

@@ -6,7 +6,7 @@ plugins {
 }
 
 group = 'cloud.eppo'
-version = '3.3.2-SNAPSHOT'
+version = '3.3.2'
 ext.isReleaseVersion = !version.endsWith("SNAPSHOT")
 
 java {

src/main/java/cloud/eppo/BaseEppoClient.java

@@ -36,6 +36,12 @@ public class BaseEppoClient {
   private final String sdkVersion;
   private boolean isGracefulMode;
 
+  @Nullable protected CompletableFuture<Boolean> getInitialConfigFuture() {
+    return initialConfigFuture;
+  }
+
+  private final CompletableFuture<Boolean> initialConfigFuture;
+
   // Fields useful for testing in situations where we want to mock the http client or configuration
   // store (accessed via reflection)
   /** @noinspection FieldMayBeFinal */
@@ -73,9 +79,10 @@ protected BaseEppoClient(
     requestor =
         new ConfigurationRequestor(
             this.configurationStore, httpClient, expectObfuscatedConfig, supportBandits);
-    if (initialConfiguration != null) {
-      requestor.setInitialConfiguration(initialConfiguration);
-    }
+    initialConfigFuture =
+        initialConfiguration != null
+            ? requestor.setInitialConfiguration(initialConfiguration)
+            : null;
 
     this.assignmentLogger = assignmentLogger;
     this.banditLogger = banditLogger;

src/main/java/cloud/eppo/ConfigurationRequestor.java

@@ -18,7 +18,7 @@ public class ConfigurationRequestor {
   private final boolean supportBandits;
 
   private CompletableFuture<Void> remoteFetchFuture = null;
-  private CompletableFuture<Void> configurationFuture = null;
+  private CompletableFuture<Boolean> configurationFuture = null;
   private boolean initialConfigSet = false;
 
   public ConfigurationRequestor(
@@ -42,38 +42,43 @@ public void setInitialConfiguration(@NotNull Configuration configuration) {
         configurationStore.saveConfiguration(configuration).thenApply(v -> true).join();
   }
 
-  // Asynchronously sets the initial configuration.
-  public CompletableFuture<Void> setInitialConfiguration(
+  /**
+   * Asynchronously sets the initial configuration. Resolves to `true` if the initial configuration
+   * was used, false if not (due to being empty, a fetched config taking precedence, etc.)
+   */
+  public CompletableFuture<Boolean> setInitialConfiguration(
       @NotNull CompletableFuture<Configuration> configurationFuture) {
     if (initialConfigSet || this.configurationFuture != null) {
       throw new IllegalStateException("Configuration future has already been set");
     }
     this.configurationFuture =
         configurationFuture
-            .thenAccept(
+            .thenApply(
                 (config) -> {
                   synchronized (configurationStore) {
                     if (config == null || config.isEmpty()) {
                       log.debug("Initial configuration future returned empty/null");
+                      return false;
                     } else if (remoteFetchFuture != null
                         && remoteFetchFuture.isDone()
                         && !remoteFetchFuture.isCompletedExceptionally()) {
                       // Don't clobber a successful fetch.
                       log.debug("Fetch has completed; ignoring initial config load.");
+                      return false;
                     } else {
-                      log.debug("saving initial configuration");
                       initialConfigSet =
                           configurationStore
                               .saveConfiguration(config)
                               .thenApply((s) -> true)
                               .join();
+                      return true;
                     }
                   }
                 })
             .exceptionally(
                 (e) -> {
                   log.error("Error setting initial config", e);
-                  return null;
+                  return false;
                 });
     return this.configurationFuture;
   }