breaking: move builder entry point to static method

Author: typotter

src/main/java/cloud/eppo/EppoClient.java

@@ -6,6 +6,7 @@
 import cloud.eppo.logging.AssignmentLogger;
 import cloud.eppo.logging.BanditLogger;
 import java.util.concurrent.TimeUnit;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -34,7 +35,7 @@ public static EppoClient getInstance() {
   }
 
   private EppoClient(
-      String apiKey,
+      String sdkKey,
       String sdkName,
       String sdkVersion,
       @Nullable String baseUrl,
@@ -44,7 +45,7 @@ private EppoClient(
       @Nullable IAssignmentCache assignmentCache,
       @Nullable IAssignmentCache banditAssignmentCache) {
     super(
-        apiKey,
+        sdkKey,
         sdkName,
         sdkVersion,
         null,
@@ -60,9 +61,18 @@ private EppoClient(
         banditAssignmentCache);
   }
 
+  /**
+   * Creates a new EppoClient Builder object with the specified SDK Key.
+   *
+   * @param sdkKey (see <a href="https://docs.geteppo.com/sdks/sdk-keys/">SDK Keys</a>)
+   */
+  public static Builder builder(@NotNull String sdkKey) {
+    return new Builder(sdkKey);
+  }
+
   /** Builder pattern to initialize the EppoClient singleton */
   public static class Builder {
-    private String apiKey;
+    private final String sdkKey;
     private AssignmentLogger assignmentLogger;
     private BanditLogger banditLogger;
     private boolean isGracefulMode = DEFAULT_IS_GRACEFUL_MODE;
@@ -76,10 +86,8 @@ public static class Builder {
     private IAssignmentCache banditAssignmentCache =
         new ExpiringInMemoryAssignmentCache(10, TimeUnit.MINUTES);
 
-    /** Sets the API Key--created within the eppo application--to use. This is required. */
-    public Builder apiKey(String apiKey) {
-      this.apiKey = apiKey;
-      return this;
+    private Builder(@NotNull String sdkKey) {
+      this.sdkKey = sdkKey;
     }
 
     /**
@@ -168,7 +176,7 @@ public EppoClient buildAndInit() {
 
       instance =
           new EppoClient(
-              apiKey,
+              sdkKey,
               sdkName,
               sdkVersion,
               apiBaseUrl,

src/test/java/cloud/eppo/EppoClientTest.java

@@ -203,7 +203,7 @@ public void testErrorGracefulModeOff() {
   @Test
   public void testReinitializeWithoutForcing() {
     EppoClient firstInstance = initClient(DUMMY_FLAG_API_KEY);
-    EppoClient secondInstance = new EppoClient.Builder().apiKey(DUMMY_FLAG_API_KEY).buildAndInit();
+    EppoClient secondInstance = EppoClient.builder(DUMMY_FLAG_API_KEY).buildAndInit();
 
     assertSame(firstInstance, secondInstance);
   }
@@ -212,7 +212,7 @@ public void testReinitializeWithoutForcing() {
   public void testReinitializeWitForcing() {
     EppoClient firstInstance = initClient(DUMMY_FLAG_API_KEY);
     EppoClient secondInstance =
-        new EppoClient.Builder().apiKey(DUMMY_FLAG_API_KEY).forceReinitialize(true).buildAndInit();
+        EppoClient.builder(DUMMY_FLAG_API_KEY).forceReinitialize(true).buildAndInit();
 
     assertNotSame(firstInstance, secondInstance);
   }
@@ -223,8 +223,7 @@ public void testPolling() {
     EppoHttpClient httpClientSpy = spy(httpClient);
     TestUtils.setBaseClientHttpClientOverrideField(httpClientSpy);
 
-    new EppoClient.Builder()
-        .apiKey(DUMMY_FLAG_API_KEY)
+    EppoClient.builder(DUMMY_FLAG_API_KEY)
         .pollingIntervalMs(20)
         .forceReinitialize(true)
         .buildAndInit();
@@ -300,8 +299,7 @@ private EppoClient initClient(String apiKey) {
     mockAssignmentLogger = mock(AssignmentLogger.class);
     mockBanditLogger = mock(BanditLogger.class);
 
-    return new EppoClient.Builder()
-        .apiKey(apiKey)
+    return EppoClient.builder(apiKey)
         .apiBaseUrl(Constants.appendApiPathToHost(TEST_HOST))
         .assignmentLogger(mockAssignmentLogger)
         .banditLogger(mockBanditLogger)
@@ -314,8 +312,7 @@ private EppoClient initFailingGracefulClient(boolean isGracefulMode) {
     mockAssignmentLogger = mock(AssignmentLogger.class);
     mockBanditLogger = mock(BanditLogger.class);
 
-    return new EppoClient.Builder()
-        .apiKey(DUMMY_FLAG_API_KEY)
+    return EppoClient.builder(DUMMY_FLAG_API_KEY)
         .apiBaseUrl("blag")
         .assignmentLogger(mockAssignmentLogger)
         .banditLogger(mockBanditLogger)