Add API to show all flag keys (#121)

* Add API to show all flag keys

* Responded to API name change request

* ternary

---------

Co-authored-by: Tyler Potter <[email protected]>

Author: hbordersTwitch

src/main/java/cloud/eppo/api/Configuration.java

@@ -170,6 +170,10 @@ public boolean isEmpty() {
     return flags == null || flags.isEmpty();
   }
 
+  public Set<String> getFlagKeys() {
+    return flags == null ? Collections.emptySet() : flags.keySet();
+  }
+
   public static Builder builder(byte[] flagJson) {
     return new Builder(flagJson);
   }

src/test/java/cloud/eppo/BaseEppoClientTest.java

@@ -742,6 +742,7 @@ public void testGetConfigurationBeforeInitialization() {
     // Verify we get an empty configuration
     assertNotNull(config);
     assertTrue(config.isEmpty());
+    assertEquals(Collections.emptySet(), config.getFlagKeys());
 
     eppoClient.loadConfiguration();
 
@@ -751,6 +752,7 @@ public void testGetConfigurationBeforeInitialization() {
     // Verify we get an empty configuration
     assertNotNull(nextConfig);
     assertFalse(nextConfig.isEmpty());
+    assertFalse(nextConfig.getFlagKeys().isEmpty());
   }
 
   @SuppressWarnings("SameParameterValue")

src/test/java/cloud/eppo/ConfigurationRequestorTest.java

@@ -11,6 +11,7 @@
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -40,11 +41,13 @@ public void testInitialConfigurationFuture() throws IOException {
 
     // verify config is empty to start
     assertTrue(configStore.getConfiguration().isEmpty());
+    assertEquals(Collections.emptySet(), configStore.getConfiguration().getFlagKeys());
     Mockito.verify(configStore, Mockito.times(0)).saveConfiguration(any());
 
     futureConfig.complete(Configuration.builder(flagConfig, false).build());
 
     assertFalse(configStore.getConfiguration().isEmpty());
+    assertFalse(configStore.getConfiguration().getFlagKeys().isEmpty());
     Mockito.verify(configStore, Mockito.times(1)).saveConfiguration(any());
     assertNotNull(configStore.getConfiguration().getFlag("numeric_flag"));
   }
@@ -69,6 +72,7 @@ public void testInitialConfigurationDoesntClobberFetch() throws IOException {
     requestor.setInitialConfiguration(initialConfigFuture);
 
     assertTrue(configStore.getConfiguration().isEmpty());
+    assertEquals(Collections.emptySet(), configStore.getConfiguration().getFlagKeys());
     Mockito.verify(configStore, Mockito.times(0)).saveConfiguration(any());
 
     // The initial config contains only one flag keyed `numeric_flag`. The fetch response has only
@@ -82,6 +86,7 @@ public void testInitialConfigurationDoesntClobberFetch() throws IOException {
     initialConfigFuture.complete(new Configuration.Builder(flagConfig, false).build());
 
     assertFalse(configStore.getConfiguration().isEmpty());
+    assertFalse(configStore.getConfiguration().getFlagKeys().isEmpty());
     Mockito.verify(configStore, Mockito.times(1)).saveConfiguration(any());
 
     // `numeric_flag` is only in the cache which should have been ignored.
@@ -109,6 +114,7 @@ public void testBrokenFetchDoesntClobberCache() throws IOException {
     requestor.setInitialConfiguration(initialConfigFuture);
 
     assertTrue(configStore.getConfiguration().isEmpty());
+    assertEquals(Collections.emptySet(), configStore.getConfiguration().getFlagKeys());
     Mockito.verify(configStore, Mockito.times(0)).saveConfiguration(any());
 
     requestor.fetchAndSaveFromRemoteAsync();
@@ -120,6 +126,7 @@ public void testBrokenFetchDoesntClobberCache() throws IOException {
     configFetchFuture.completeExceptionally(new Exception("Intentional exception"));
 
     assertFalse(configStore.getConfiguration().isEmpty());
+    assertFalse(configStore.getConfiguration().getFlagKeys().isEmpty());
     Mockito.verify(configStore, Mockito.times(1)).saveConfiguration(any());
 
     // `numeric_flag` is only in the cache which should be available
@@ -148,6 +155,7 @@ public void testCacheWritesAfterBrokenFetch() throws IOException {
 
     // default configuration is empty config.
     assertTrue(configStore.getConfiguration().isEmpty());
+    assertEquals(Collections.emptySet(), configStore.getConfiguration().getFlagKeys());
 
     // Fetch from remote with an error
     requestor.fetchAndSaveFromRemoteAsync();
@@ -159,6 +167,7 @@ public void testCacheWritesAfterBrokenFetch() throws IOException {
     // Verify that a configuration was saved by the requestor
     Mockito.verify(configStore, Mockito.times(1)).saveConfiguration(any());
     assertFalse(configStore.getConfiguration().isEmpty());
+    assertFalse(configStore.getConfiguration().getFlagKeys().isEmpty());
 
     // `numeric_flag` is only in the cache which should be available
     assertNotNull(configStore.getConfiguration().getFlag("numeric_flag"));