feat: re-init / manual sync config specs (#394)

Please see this pr for details:
statsig-io/private-java-server-sdk#392

src/main/kotlin/com/statsig/sdk/Evaluator.kt

@@ -83,6 +83,13 @@ internal class Evaluator(
         specStore.shutdown()
     }
 
+    suspend fun syncConfigSpecs(): FailureDetails? {
+        if (!isInitialized) {
+            return FailureDetails(FailureReason.EMPTY_SPEC)
+        }
+        return specStore.syncConfigSpecs()
+    }
+
     private fun createEvaluationDetails(reason: EvaluationReason): EvaluationDetails {
         if (reason == EvaluationReason.UNINITIALIZED) {
             return EvaluationDetails(0, 0, reason)

src/main/kotlin/com/statsig/sdk/InitializationDetails.kt

@@ -13,6 +13,11 @@ data class InitializationDetails(
     var failureDetails: FailureDetails? = null,
 )
 
+data class ConfigSyncDetails(
+    @SerializedName("details")
+    var details: InitializationDetails
+)
+
 data class FailureDetails(
     @SerializedName("reason") var reason: FailureReason,
     @SerializedName("exception") var exception: Exception? = null,

src/main/kotlin/com/statsig/sdk/SpecStore.kt

@@ -49,7 +49,7 @@ internal class SpecStore(
         if (!options.localMode) {
             specUpdater.initialize()
 
-            var failureDetails = this.initializeSpecs()
+            val failureDetails = this.initializeSpecs()
             this.initTime = if (specUpdater.lastUpdateTime == 0L) -1 else specUpdater.lastUpdateTime
 
             this.syncIdListsFromNetwork(specUpdater.updateIDLists())
@@ -67,6 +67,10 @@ internal class SpecStore(
         this.specUpdater.shutdown()
     }
 
+    suspend fun syncConfigSpecs(): FailureDetails? {
+        return initializeSpecs()
+    }
+
     fun setDownloadedConfigs(downloadedConfig: APIDownloadedConfigs, isFromBootstrap: Boolean = false): Boolean {
         if (!downloadedConfig.hasUpdates) {
             return false

src/main/kotlin/com/statsig/sdk/Statsig.kt

@@ -784,6 +784,17 @@ class Statsig {
             runBlocking { statsigServer.shutdown() }
         }
 
+        /**
+         * Manually sync config specs if initialize is failed
+         */
+        @JvmStatic
+        fun syncConfigSpecs(): CompletableFuture<ConfigSyncDetails> {
+            if (!checkInitialized()) {
+                return CompletableFuture.completedFuture(ConfigSyncDetails(InitializationDetails(0, false, false)))
+            }
+            return statsigServer.syncConfigSpecs()
+        }
+
         @JvmStatic
         fun isInitialized(): Boolean {
             return ::statsigServer.isInitialized && statsigServer.initialized.get()

src/main/kotlin/com/statsig/sdk/StatsigServer.kt

@@ -46,6 +46,8 @@ sealed class StatsigServer {
     @JvmSynthetic
     abstract suspend fun manuallyLogConfigExposure(user: StatsigUser, configName: String)
 
+    abstract fun syncConfigSpecs(): CompletableFuture<ConfigSyncDetails>
+
     @JvmSynthetic
     abstract suspend fun getExperiment(user: StatsigUser, experimentName: String): DynamicConfig
 
@@ -583,6 +585,31 @@ private class StatsigServerImpl() :
         }
     }
 
+    override fun syncConfigSpecs(): CompletableFuture<ConfigSyncDetails> {
+        return statsigScope.future {
+            errorBoundary.capture("syncConfigSpecs", {
+                val failureDetails = evaluator.syncConfigSpecs()
+                ConfigSyncDetails(
+                    InitializationDetails(
+                        System.currentTimeMillis() - setupStartTime,
+                        isSDKReady = isSDKInitialized(),
+                        configSpecReady = failureDetails == null,
+                        failureDetails,
+                    )
+                )
+            }, {
+                ConfigSyncDetails(
+                    InitializationDetails(
+                        System.currentTimeMillis() - setupStartTime,
+                        isSDKReady = isSDKInitialized(),
+                        configSpecReady = false,
+                        FailureDetails(FailureReason.INTERNAL_ERROR),
+                    )
+                )
+            })
+        }
+    }
+
     override suspend fun getExperiment(user: StatsigUser, experimentName: String): DynamicConfig {
         if (!isSDKInitialized()) {
             return DynamicConfig.empty(experimentName)

src/test/java/com/statsig/sdk/APIOverrideTest.kt

@@ -5,6 +5,7 @@ import okhttp3.mockwebserver.Dispatcher
 import okhttp3.mockwebserver.MockResponse
 import okhttp3.mockwebserver.MockWebServer
 import okhttp3.mockwebserver.RecordedRequest
+import org.junit.After
 import org.junit.Before
 import org.junit.Test
 
@@ -41,6 +42,7 @@ class APIOverrideTest {
                 }
             }
         }
+
         server2.apply {
             dispatcher = object : Dispatcher() {
                 @Throws(InterruptedException::class)
@@ -89,6 +91,13 @@ class APIOverrideTest {
         server3Calls.clear()
     }
 
+    @After
+    fun tearDown() {
+        server1.shutdown()
+        server2.shutdown()
+        server3.shutdown()
+    }
+
     @Test
     fun testAPIOverride() {
         val options = StatsigOptions(

src/test/java/com/statsig/sdk/StatsigE2ETest.kt

@@ -204,6 +204,7 @@ class StatsigE2ETest {
     @After
     fun afterEach() {
         server.shutdown()
+        driver.shutdown()
     }
 
     @Test

src/test/java/com/statsig/sdk/StatsigReinitializeTest.java

@@ -0,0 +1,101 @@
+package com.statsig.sdk;
+
+import okhttp3.mockwebserver.Dispatcher;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import okhttp3.mockwebserver.RecordedRequest;
+import org.jetbrains.annotations.NotNull;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Objects;
+import java.util.concurrent.CompletableFuture;
+
+public class StatsigReinitializeTest {
+
+    private static final int MAX_CNT = 2;
+
+    private MockWebServer server;
+    private StatsigOptions options;
+    private int requestCnt;
+    private String configSpecsResponse;
+
+    @Before
+    public void setUp() throws IOException {
+        configSpecsResponse = new String(Files.readAllBytes(Paths.get(Objects.requireNonNull(getClass().getResource("/download_config_specs.json")).getPath())));
+        server = new MockWebServer();
+        requestCnt = 0;
+        server.setDispatcher(new Dispatcher() {
+            @NotNull
+            @Override
+            public MockResponse dispatch(@NotNull RecordedRequest request) {
+                // Simulate failure on first request, success on subsequent requests
+                if (request.getPath().contains("v1/download_config_specs")) {
+                    if (requestCnt < MAX_CNT) {
+                        requestCnt++;
+                        return new MockResponse().setResponseCode(500);
+                    } else {
+                        return new MockResponse().setResponseCode(200).setBody(configSpecsResponse);
+                    }
+                }
+                return new MockResponse().setResponseCode(200);
+            }
+        });
+
+        server.start(1080);
+
+        options = new StatsigOptions();
+        options.setApi(server.url("/v1").toString());
+        options.setDisableDiagnostics(true);
+    }
+
+    @After
+    public void tearDown() throws IOException {
+        server.shutdown();
+        Statsig.shutdown();
+    }
+
+    @Test
+    public void testReinitialize() throws Exception {
+        CompletableFuture<InitializationDetails> detailsFuture = Statsig.initializeAsync("server-secret", options);
+        StatsigUser user = new StatsigUser("123");
+        user.setEmail("[email protected]");
+
+        InitializationDetails details = detailsFuture.get();
+        Assert.assertNotNull(details);
+        Assert.assertTrue(details.isSDKReady());
+        Assert.assertFalse(details.getConfigSpecReady());  // First init should fail due to 500 response
+        Assert.assertNotNull(details.getFailureDetails());  // Expect failure details for the first init
+        Assert.assertFalse(Statsig.checkGateSync(user, "always_on_gate"));
+        Assert.assertFalse(Statsig.checkGateSync(user, "on_for_statsig_email"));
+        Layer layer1 = Statsig.getLayerSync(user, "c_layer_with_holdout");
+        Assert.assertEquals(layer1.getString("holdout_layer_param", "should_return_default"), "should_return_default");
+
+
+        CompletableFuture<ConfigSyncDetails> details2Future = Statsig.syncConfigSpecs();
+        ConfigSyncDetails details2 = details2Future.get();
+        Assert.assertNotNull(details2);
+        Assert.assertTrue(details2.getDetails().isSDKReady());
+        Assert.assertFalse(details2.getDetails().getConfigSpecReady());  // Second try should also fail
+        Assert.assertFalse(Statsig.checkGateSync(user, "always_on_gate"));
+        Assert.assertFalse(Statsig.checkGateSync(user, "on_for_statsig_email"));
+        Layer layer2 = Statsig.getLayerSync(user, "c_layer_with_holdout");
+        Assert.assertEquals(layer2.getString("holdout_layer_param", "should_return_default"), "should_return_default");
+
+        CompletableFuture<ConfigSyncDetails> details3Future = Statsig.syncConfigSpecs();
+        ConfigSyncDetails details3 = details3Future.get();
+        Assert.assertNotNull(details3);
+        Assert.assertTrue(details3.getDetails().isSDKReady());
+        Assert.assertTrue(details3.getDetails().getConfigSpecReady());  // Third try should succeed with 200 response
+        Assert.assertNull(details3.getDetails().getFailureDetails());  // No failure details expected for successful init
+        Assert.assertTrue(Statsig.checkGateSync(user, "always_on_gate"));
+        Assert.assertTrue(Statsig.checkGateSync(user, "on_for_statsig_email"));
+        Layer layer3 = Statsig.getLayerSync(user, "c_layer_with_holdout");
+        Assert.assertEquals(layer3.getString("holdout_layer_param", "should_not_return_default"), "layer_default");
+    }
+}