Refactor ChromaVectorStore builder API

The commit restructures the ChromaVectorStore builder pattern to use a no-args constructor
with fluent API for setting the ChromaApi.

This change:

 - Makes builder creation consistent with other vector stores
 - Moves ChromaApi validation to the doValidate method
 - Improves builder API ergonomics

The change requires updating all builder usages to use the new .chromaApi() method instead
of passing it in the constructor.

Author: sobychacko

spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/vectorstore/chroma/ChromaVectorStoreAutoConfiguration.java

@@ -86,7 +86,8 @@ public ChromaVectorStore vectorStore(EmbeddingModel embeddingModel, ChromaApi ch
 			ChromaVectorStoreProperties storeProperties, ObjectProvider<ObservationRegistry> observationRegistry,
 			ObjectProvider<VectorStoreObservationConvention> customObservationConvention,
 			BatchingStrategy chromaBatchingStrategy) {
-		return ChromaVectorStore.builder(chromaApi)
+		return ChromaVectorStore.builder()
+			.chromaApi(chromaApi)
 			.embeddingModel(embeddingModel)
 			.collectionName(storeProperties.getCollectionName())
 			.initializeSchema(storeProperties.isInitializeSchema())

vector-stores/spring-ai-chroma-store/src/main/java/org/springframework/ai/chroma/vectorstore/ChromaVectorStore.java

@@ -102,7 +102,8 @@ public ChromaVectorStore(EmbeddingModel embeddingModel, ChromaApi chromaApi, Str
 			boolean initializeSchema, ObservationRegistry observationRegistry,
 			VectorStoreObservationConvention customObservationConvention, BatchingStrategy batchingStrategy) {
 
-		this(builder(chromaApi).embeddingModel(embeddingModel)
+		this(builder().chromaApi(chromaApi)
+			.embeddingModel(embeddingModel)
 			.collectionName(collectionName)
 			.initializeSchema(initializeSchema)
 			.observationRegistry(observationRegistry)
@@ -113,8 +114,11 @@ public ChromaVectorStore(EmbeddingModel embeddingModel, ChromaApi chromaApi, Str
 	/**
 	 * @param builder {@link Builder} for chroma vector store
 	 */
-	private ChromaVectorStore(ChromaBuilder builder) {
+	protected ChromaVectorStore(ChromaBuilder builder) {
 		super(builder);
+
+		Assert.notNull(builder.chromaApi, "ChromaApi must not be null");
+
 		this.chromaApi = builder.chromaApi;
 		this.collectionName = builder.collectionName;
 		this.initializeSchema = builder.initializeSchema;
@@ -151,8 +155,8 @@ public void afterPropertiesSet() throws Exception {
 		}
 	}
 
-	public static ChromaBuilder builder(ChromaApi chromaApi) {
-		return new ChromaBuilder(chromaApi);
+	public static ChromaBuilder builder() {
+		return new ChromaBuilder();
 	}
 
 	@Override
@@ -274,7 +278,7 @@ public VectorStoreObservationContext.Builder createObservationContextBuilder(Str
 
 	public static class ChromaBuilder extends AbstractVectorStoreBuilder<ChromaBuilder> {
 
-		private final ChromaApi chromaApi;
+		private ChromaApi chromaApi;
 
 		private String collectionName = DEFAULT_COLLECTION_NAME;
 
@@ -286,9 +290,10 @@ public static class ChromaBuilder extends AbstractVectorStoreBuilder<ChromaBuild
 
 		private boolean initializeImmediately = false;
 
-		public ChromaBuilder(ChromaApi chromaApi) {
+		public ChromaBuilder chromaApi(ChromaApi chromaApi) {
 			Assert.notNull(chromaApi, "ChromaApi must not be null");
 			this.chromaApi = chromaApi;
+			return this;
 		}
 
 		/**

vector-stores/spring-ai-chroma-store/src/test/java/org/springframework/ai/chroma/vectorstore/BasicAuthChromaWhereIT.java

@@ -111,7 +111,8 @@ public ChromaApi chromaApi(RestClient.Builder builder) {
 
 		@Bean
 		public VectorStore chromaVectorStore(EmbeddingModel embeddingModel, ChromaApi chromaApi) {
-			return ChromaVectorStore.builder(chromaApi)
+			return ChromaVectorStore.builder()
+				.chromaApi(chromaApi)
 				.embeddingModel(embeddingModel)
 				.collectionName("TestCollection")
 				.initializeSchema(true)

vector-stores/spring-ai-chroma-store/src/test/java/org/springframework/ai/chroma/vectorstore/ChromaApiIT.java

@@ -207,7 +207,8 @@ void shouldUseExistingCollectionWhenSchemaInitializationDisabled() { // initiali
 		assertThat(collection).isNotNull();
 		assertThat(collection.name()).isEqualTo("test-collection");
 
-		ChromaVectorStore store = ChromaVectorStore.builder(this.chromaApi)
+		ChromaVectorStore store = ChromaVectorStore.builder()
+			.chromaApi(this.chromaApi)
 			.embeddingModel(this.embeddingModel)
 			.collectionName("test-collection")
 			.initializeImmediately(true)
@@ -219,7 +220,7 @@ void shouldUseExistingCollectionWhenSchemaInitializationDisabled() { // initiali
 
 	@Test
 	void shouldCreateNewCollectionWhenSchemaInitializationEnabled() {
-		ChromaVectorStore store = new ChromaVectorStore.ChromaBuilder(this.chromaApi)
+		ChromaVectorStore store = new ChromaVectorStore.ChromaBuilder().chromaApi(this.chromaApi)
 			.embeddingModel(this.embeddingModel)
 			.collectionName("new-collection")
 			.initializeSchema(true)
@@ -236,7 +237,8 @@ void shouldCreateNewCollectionWhenSchemaInitializationEnabled() {
 
 	@Test
 	void shouldFailWhenCollectionDoesNotExist() {
-		assertThatThrownBy(() -> new ChromaVectorStore.ChromaBuilder(this.chromaApi).embeddingModel(this.embeddingModel)
+		assertThatThrownBy(() -> new ChromaVectorStore.ChromaBuilder().chromaApi(this.chromaApi)
+			.embeddingModel(this.embeddingModel)
 			.collectionName("non-existent")
 			.initializeSchema(false)
 			.initializeImmediately(true)

vector-stores/spring-ai-chroma-store/src/test/java/org/springframework/ai/chroma/vectorstore/ChromaVectorStoreIT.java

@@ -252,7 +252,8 @@ public ChromaApi chromaApi(RestClient.Builder builder) {
 
 		@Bean
 		public VectorStore chromaVectorStore(EmbeddingModel embeddingModel, ChromaApi chromaApi) {
-			return ChromaVectorStore.builder(chromaApi)
+			return ChromaVectorStore.builder()
+				.chromaApi(chromaApi)
 				.embeddingModel(embeddingModel)
 				.collectionName("TestCollection")
 				.initializeSchema(true)

vector-stores/spring-ai-chroma-store/src/test/java/org/springframework/ai/chroma/vectorstore/ChromaVectorStoreObservationIT.java

@@ -176,7 +176,8 @@ public ChromaApi chromaApi(RestClient.Builder builder) {
 		@Bean
 		public VectorStore chromaVectorStore(EmbeddingModel embeddingModel, ChromaApi chromaApi,
 				ObservationRegistry observationRegistry) {
-			return ChromaVectorStore.builder(chromaApi)
+			return ChromaVectorStore.builder()
+				.chromaApi(chromaApi)
 				.embeddingModel(embeddingModel)
 				.collectionName("TestCollection")
 				.initializeSchema(true)

vector-stores/spring-ai-chroma-store/src/test/java/org/springframework/ai/chroma/vectorstore/TokenSecuredChromaWhereIT.java

@@ -144,7 +144,8 @@ public ChromaApi chromaApi(RestClient.Builder builder) {
 
 		@Bean
 		public VectorStore chromaVectorStore(EmbeddingModel embeddingModel, ChromaApi chromaApi) {
-			return ChromaVectorStore.builder(chromaApi)
+			return ChromaVectorStore.builder()
+				.chromaApi(chromaApi)
 				.embeddingModel(embeddingModel)
 				.collectionName("TestCollection")
 				.initializeSchema(true)