Add additional OpenAI TTS Voice options

 - Add OpenAI TTS Voice Unit Test

Author: hgs-study

models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiAudioApi.java

@@ -392,7 +392,13 @@ public enum Voice {
 			@JsonProperty("nova")
 			NOVA("nova"),
 			@JsonProperty("shimmer")
-			SHIMMER("shimmer");
+			SHIMMER("shimmer"),
+			@JsonProperty("sage")
+			SAGE("sage"),
+			@JsonProperty("coral")
+			CORAL("coral"),
+			@JsonProperty("ash")
+			ASH("ash");
 			// @formatter:on
 
 			public final String value;

models/spring-ai-openai/src/test/java/org/springframework/ai/openai/audio/speech/OpenAiSpeechModelIT.java

@@ -20,6 +20,8 @@
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import reactor.core.publisher.Flux;
 
 import org.springframework.ai.openai.OpenAiAudioSpeechOptions;
@@ -111,4 +113,22 @@ void shouldStreamNonEmptyResponsesForValidSpeechPrompts() {
 		assertThat(response.getResult().getOutput()).isNotEmpty());
 	}
 
+	@ParameterizedTest(name = "{0} : {displayName} ")
+	@ValueSource(strings = { "alloy", "echo", "fable", "onyx", "nova", "shimmer", "sage", "coral", "ash" })
+	void speechVoicesTest(String voice) {
+		OpenAiAudioSpeechOptions speechOptions = OpenAiAudioSpeechOptions.builder()
+			.voice(OpenAiAudioApi.SpeechRequest.Voice.valueOf(voice.toUpperCase()))
+			.speed(SPEED)
+			.responseFormat(OpenAiAudioApi.SpeechRequest.AudioResponseFormat.MP3)
+			.model(OpenAiAudioApi.TtsModel.TTS_1.value)
+			.build();
+		SpeechPrompt speechPrompt = new SpeechPrompt("Today is a wonderful day to build something people love!",
+				speechOptions);
+		SpeechResponse response = this.speechModel.call(speechPrompt);
+		byte[] audioBytes = response.getResult().getOutput();
+		assertThat(response.getResults()).hasSize(1);
+		assertThat(response.getResults().get(0).getOutput()).isNotEmpty();
+		assertThat(audioBytes).hasSizeGreaterThan(0);
+	}
+
 }