Enhance OpenAiChatOptions test coverage (spring-projects#3959)

Tests Added

- testEqualsAndHashCode() - equals/hashCode contract validation
- testBuilderWithNullValues() - builder with null inputs
- testBuilderChaining() - builder method chaining
- testNullAndEmptyCollections() - null/empty collection handling
- testStreamUsageStreamOptionsInteraction() - stream options state sync
- testStopSequencesAlias() - stop/stopSequences field sync
- testFromOptionsWithWebSearchOptionsNull() - fromOptions with null webSearch
- testCopyChangeIndependence() - copy mutation independence validation

Signed-off-by: Alex Klimenko <[email protected]>
Signed-off-by: 家娃 <[email protected]>

Author: alxkm

models/spring-ai-openai/src/test/java/org/springframework/ai/openai/OpenAiChatOptionsTests.java

@@ -284,4 +284,173 @@ void testFromOptions_webSearchOptions() {
 		assertThat(target.getWebSearchOptions().userLocation().approximate().timezone()).isEqualTo("UTC+8");
 	}
 
+	@Test
+	void testEqualsAndHashCode() {
+		OpenAiChatOptions options1 = OpenAiChatOptions.builder()
+			.model("test-model")
+			.temperature(0.7)
+			.maxTokens(100)
+			.build();
+
+		OpenAiChatOptions options2 = OpenAiChatOptions.builder()
+			.model("test-model")
+			.temperature(0.7)
+			.maxTokens(100)
+			.build();
+
+		OpenAiChatOptions options3 = OpenAiChatOptions.builder()
+			.model("different-model")
+			.temperature(0.7)
+			.maxTokens(100)
+			.build();
+
+		// Test equals
+		assertThat(options1).isEqualTo(options2);
+		assertThat(options1).isNotEqualTo(options3);
+		assertThat(options1).isNotEqualTo(null);
+		assertThat(options1).isEqualTo(options1);
+
+		// Test hashCode
+		assertThat(options1.hashCode()).isEqualTo(options2.hashCode());
+		assertThat(options1.hashCode()).isNotEqualTo(options3.hashCode());
+	}
+
+	@Test
+	void testBuilderWithNullValues() {
+		OpenAiChatOptions options = OpenAiChatOptions.builder()
+			.temperature(null)
+			.logitBias(null)
+			.stop(null)
+			.tools(null)
+			.metadata(null)
+			.build();
+
+		assertThat(options.getModel()).isNull();
+		assertThat(options.getTemperature()).isNull();
+		assertThat(options.getLogitBias()).isNull();
+		assertThat(options.getStop()).isNull();
+		assertThat(options.getTools()).isNull();
+		assertThat(options.getMetadata()).isNull();
+	}
+
+	@Test
+	void testBuilderChaining() {
+		OpenAiChatOptions.Builder builder = OpenAiChatOptions.builder();
+
+		OpenAiChatOptions.Builder result = builder.model("test-model").temperature(0.7).maxTokens(100);
+
+		assertThat(result).isSameAs(builder);
+
+		OpenAiChatOptions options = result.build();
+		assertThat(options.getModel()).isEqualTo("test-model");
+		assertThat(options.getTemperature()).isEqualTo(0.7);
+		assertThat(options.getMaxTokens()).isEqualTo(100);
+	}
+
+	@Test
+	void testNullAndEmptyCollections() {
+		OpenAiChatOptions options = new OpenAiChatOptions();
+
+		// Test setting null collections
+		options.setLogitBias(null);
+		options.setStop(null);
+		options.setTools(null);
+		options.setMetadata(null);
+		options.setOutputModalities(null);
+
+		assertThat(options.getLogitBias()).isNull();
+		assertThat(options.getStop()).isNull();
+		assertThat(options.getTools()).isNull();
+		assertThat(options.getMetadata()).isNull();
+		assertThat(options.getOutputModalities()).isNull();
+
+		// Test setting empty collections
+		options.setLogitBias(new HashMap<>());
+		options.setStop(new ArrayList<>());
+		options.setTools(new ArrayList<>());
+		options.setMetadata(new HashMap<>());
+		options.setOutputModalities(new ArrayList<>());
+
+		assertThat(options.getLogitBias()).isEmpty();
+		assertThat(options.getStop()).isEmpty();
+		assertThat(options.getTools()).isEmpty();
+		assertThat(options.getMetadata()).isEmpty();
+		assertThat(options.getOutputModalities()).isEmpty();
+	}
+
+	@Test
+	void testStreamUsageStreamOptionsInteraction() {
+		OpenAiChatOptions options = new OpenAiChatOptions();
+
+		// Initially false
+		assertThat(options.getStreamUsage()).isFalse();
+		assertThat(options.getStreamOptions()).isNull();
+
+		// Setting streamUsage to true should set streamOptions
+		options.setStreamUsage(true);
+		assertThat(options.getStreamUsage()).isTrue();
+		assertThat(options.getStreamOptions()).isEqualTo(StreamOptions.INCLUDE_USAGE);
+
+		// Setting streamUsage to false should clear streamOptions
+		options.setStreamUsage(false);
+		assertThat(options.getStreamUsage()).isFalse();
+		assertThat(options.getStreamOptions()).isNull();
+
+		// Setting streamOptions directly should update streamUsage
+		options.setStreamOptions(StreamOptions.INCLUDE_USAGE);
+		assertThat(options.getStreamUsage()).isTrue();
+		assertThat(options.getStreamOptions()).isEqualTo(StreamOptions.INCLUDE_USAGE);
+
+		// Setting streamOptions to null should set streamUsage to false
+		options.setStreamOptions(null);
+		assertThat(options.getStreamUsage()).isFalse();
+		assertThat(options.getStreamOptions()).isNull();
+	}
+
+	@Test
+	void testStopSequencesAlias() {
+		OpenAiChatOptions options = new OpenAiChatOptions();
+		List<String> stopSequences = List.of("stop1", "stop2");
+
+		// Setting stopSequences should also set stop
+		options.setStopSequences(stopSequences);
+		assertThat(options.getStopSequences()).isEqualTo(stopSequences);
+		assertThat(options.getStop()).isEqualTo(stopSequences);
+
+		// Setting stop should also update stopSequences
+		List<String> newStop = List.of("stop3", "stop4");
+		options.setStop(newStop);
+		assertThat(options.getStop()).isEqualTo(newStop);
+		assertThat(options.getStopSequences()).isEqualTo(newStop);
+	}
+
+	@Test
+	void testFromOptionsWithWebSearchOptionsNull() {
+		OpenAiChatOptions source = OpenAiChatOptions.builder()
+			.model("test-model")
+			.temperature(0.7)
+			.webSearchOptions(null)
+			.build();
+
+		OpenAiChatOptions result = OpenAiChatOptions.fromOptions(source);
+		assertThat(result.getModel()).isEqualTo("test-model");
+		assertThat(result.getTemperature()).isEqualTo(0.7);
+		assertThat(result.getWebSearchOptions()).isNull();
+	}
+
+	@Test
+	void testCopyChangeIndependence() {
+		OpenAiChatOptions original = OpenAiChatOptions.builder().model("original-model").temperature(0.5).build();
+
+		OpenAiChatOptions copied = original.copy();
+
+		// Modify original
+		original.setModel("modified-model");
+		original.setTemperature(0.9);
+
+		// Verify copy is unchanged
+		assertThat(copied.getModel()).isEqualTo("original-model");
+		assertThat(copied.getTemperature()).isEqualTo(0.5);
+	}
+
 }