Pass through Common SDK API (#71)

* wip

* target Java 8

* linter 🙄

Author: aarsilv

build.gradle

@@ -5,8 +5,13 @@ plugins {
   id "com.diffplug.spotless" version "6.13.0"
 }
 
+java {
+  sourceCompatibility = JavaVersion.VERSION_1_8
+  targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 group = 'cloud.eppo'
-version = '3.0.0-SNAPSHOT'
+version = '3.0.1-SNAPSHOT'
 ext.isReleaseVersion = !version.endsWith("SNAPSHOT")
 
 import org.apache.tools.ant.filters.ReplaceTokens
@@ -25,10 +30,11 @@ repositories {
 }
 
 dependencies {
-  implementation 'cloud.eppo:sdk-common-jvm:3.0.1-SNAPSHOT'
+  // Re-export classes and interfaces that will be used upstream
+  api 'cloud.eppo:sdk-common-jvm:3.0.2-SNAPSHOT'
+
   implementation 'com.github.zafarkhaja:java-semver:0.10.2'
   implementation 'com.fasterxml.jackson.core:jackson-databind:2.17.1'
-  implementation 'org.apache.httpcomponents:httpclient:4.5.14'
   implementation 'org.ehcache:ehcache:3.10.8'
   implementation 'org.slf4j:slf4j-api:2.0.13'
   // Logback classic 1.3.x is compatible with java 8
@@ -128,16 +134,18 @@ publishing {
   }
 }
 
-signing {
-  sign publishing.publications.mavenJava
-  if (System.env['CI']) {
-    useInMemoryPgpKeys(System.env.GPG_PRIVATE_KEY, System.env.GPG_PASSPHRASE)
+if (!project.gradle.startParameter.taskNames.contains('publishToMavenLocal')) {
+  signing {
+    sign publishing.publications.mavenJava
+    if (System.env['CI']) {
+      useInMemoryPgpKeys(System.env.GPG_PRIVATE_KEY, System.env.GPG_PASSPHRASE)
+    }
   }
 }
 
-
 javadoc {
   if (JavaVersion.current().isJava9Compatible()) {
     options.addBooleanOption('html5', true)
   }
+  options.addStringOption('Xdoclint:none', '-quiet')
 }

src/main/java/com/eppo/sdk/EppoClient.java

@@ -9,6 +9,12 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/**
+ * Class used to ingest and use the flag and bandit configurations retrieved from Eppo This class
+ * uses the Singleton pattern. First the singleton must be initialized via it's Builder's
+ * buildAndInit() method. Then call getInstance() to access the singleton and call methods to get
+ * assignments and bandit actions.
+ */
 public class EppoClient extends BaseEppoClient {
   private static final Logger log = LoggerFactory.getLogger(EppoClient.class);
 
@@ -40,63 +46,92 @@ private EppoClient(
         apiKey, host, sdkName, sdkVersion, assignmentLogger, banditLogger, isGracefulModel, false);
   }
 
+  /** Stops the client from polling Eppo for updated flag and bandit configurations */
   public static void stopPolling() {
     if (pollTimer != null) {
       pollTimer.cancel();
     }
   }
 
+  /** Builder pattern to initialize the EppoClient singleton */
   public static class Builder {
     private String apiKey;
-    private String host = DEFAULT_HOST;
     private AssignmentLogger assignmentLogger;
     private BanditLogger banditLogger;
     private boolean isGracefulMode = DEFAULT_IS_GRACEFUL_MODE;
     private boolean forceReinitialize = DEFAULT_FORCE_REINITIALIZE;
     private long pollingIntervalMs = DEFAULT_POLLING_INTERVAL_MS;
+    private String host = DEFAULT_HOST;
 
+    /** Sets the API Key--created within the eppo application--to use. This is required. */
     public Builder apiKey(String apiKey) {
       this.apiKey = apiKey;
       return this;
     }
 
-    public Builder host(String host) {
-      this.host = host;
-      return this;
-    }
-
+    /**
+     * Assignment logger to use to record when variations were assigned. This is needed if you want
+     * Eppo to analyze experiments controlled by flags.
+     */
     public Builder assignmentLogger(AssignmentLogger assignmentLogger) {
       this.assignmentLogger = assignmentLogger;
       return this;
     }
 
+    /**
+     * Bandit logger to use to record when a bandit has assigned an action. This is needed if you
+     * are using contextual multi-armed bandits.
+     */
     public Builder banditLogger(BanditLogger banditLogger) {
       this.banditLogger = banditLogger;
       return this;
     }
 
+    /**
+     * Sets the initial graceful mode of the client. When on (which is the default), flag evaluation
+     * errors will be caught, and the default value returned. When off, the errors will be rethrown.
+     */
     public Builder isGracefulMode(boolean isGracefulMode) {
       this.isGracefulMode = isGracefulMode;
       return this;
     }
 
+    /**
+     * Sets whether the singleton client should be recreated if one already has been. fetch an
+     * updated configuration. If true, a new client will be instantiated and a new fetch for
+     * configurations will be performed. If false (which is the default), initialization will be
+     * ignored and the previously initialized client will be used.
+     */
     public Builder forceReinitialize(boolean forceReinitialize) {
       this.forceReinitialize = forceReinitialize;
       return this;
     }
 
+    /**
+     * Sets how often the client should check for updated configurations, in milliseconds. The
+     * default is 30,000 (poll every 30 seconds).
+     */
     public Builder pollingIntervalMs(long pollingIntervalMs) {
       this.pollingIntervalMs = pollingIntervalMs;
       return this;
     }
 
+    /**
+     * Overrides the host from where it fetches configurations. This typically should not be
+     * explicitly set so that the default of the Fastly CDN is used.
+     */
+    public Builder host(String host) {
+      this.host = host;
+      return this;
+    }
+
     public EppoClient buildAndInit() {
       AppDetails appDetails = AppDetails.getInstance();
       String sdkName = appDetails.getName();
       String sdkVersion = appDetails.getVersion();
 
       if (instance != null) {
-        if (forceReinitialize) { // TODO: unit test this
+        if (forceReinitialize) {
           log.warn(
               "Eppo SDK is already initialized, reinitializing since forceReinitialize is true");
         } else {

src/test/java/com/eppo/sdk/EppoClientTest.java

@@ -10,14 +10,16 @@
 
 import cloud.eppo.BaseEppoClient;
 import cloud.eppo.EppoHttpClient;
+import cloud.eppo.api.Attributes;
+import cloud.eppo.api.BanditActions;
+import cloud.eppo.api.BanditResult;
 import cloud.eppo.helpers.AssignmentTestCase;
 import cloud.eppo.helpers.BanditTestCase;
 import cloud.eppo.helpers.TestUtils;
 import cloud.eppo.logging.Assignment;
 import cloud.eppo.logging.AssignmentLogger;
 import cloud.eppo.logging.BanditAssignment;
 import cloud.eppo.logging.BanditLogger;
-import cloud.eppo.ufc.dto.*;
 import com.github.tomakehurst.wiremock.WireMockServer;
 import com.github.tomakehurst.wiremock.client.WireMock;
 import com.github.tomakehurst.wiremock.junit5.WireMockExtension;