test: Add comprehensive edge case tests for Ollama embedding and chat models

models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/OllamaChatModelTests.java

@@ -325,4 +325,28 @@ void buildOllamaChatModelImmutability() {
 		assertThat(chatModel2).isNotNull();
 	}
 
+	@Test
+	void buildChatResponseMetadataWithZeroValues() {
+		// Test with all zero/minimal values
+		OllamaApi.ChatResponse response = new OllamaApi.ChatResponse("model", Instant.now(), null, null, null, 0L, 0L,
+				0, 0L, 0, 0L);
+
+		ChatResponseMetadata metadata = OllamaChatModel.from(response, null);
+
+		assertEquals(Duration.ZERO, metadata.get("eval-duration"));
+		assertEquals(Integer.valueOf(0), metadata.get("eval-count"));
+		assertEquals(Duration.ZERO, metadata.get("prompt-eval-duration"));
+		assertEquals(Integer.valueOf(0), metadata.get("prompt-eval-count"));
+		assertThat(metadata.getUsage()).isEqualTo(new DefaultUsage(0, 0));
+	}
+
+	@Test
+	void buildOllamaChatModelWithMinimalConfiguration() {
+		// Test building with only required parameters
+		ChatModel chatModel = OllamaChatModel.builder().ollamaApi(this.ollamaApi).build();
+
+		assertThat(chatModel).isNotNull();
+		assertThat(chatModel).isInstanceOf(OllamaChatModel.class);
+	}
+
 }

models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/OllamaEmbeddingRequestTests.java

@@ -185,4 +185,44 @@ public void ollamaEmbeddingRequestWithWhitespaceInputs() {
 		assertThat(ollamaRequest.input()).containsExactly("", "   ", "\t\n", "normal text", "  spaced  ");
 	}
 
+	@Test
+	public void ollamaEmbeddingRequestWithNullInput() {
+		// Test behavior when input list contains null values
+		List<String> inputsWithNull = Arrays.asList("Hello", null, "World");
+		var embeddingRequest = this.embeddingModel.buildEmbeddingRequest(new EmbeddingRequest(inputsWithNull, null));
+		var ollamaRequest = this.embeddingModel.ollamaEmbeddingRequest(embeddingRequest);
+
+		assertThat(ollamaRequest.input()).containsExactly("Hello", null, "World");
+		assertThat(ollamaRequest.input()).hasSize(3);
+	}
+
+	@Test
+	public void ollamaEmbeddingRequestPartialOptionsOverride() {
+		// Test that only specified options are overridden, others remain default
+		var requestOptions = OllamaOptions.builder()
+			.model("PARTIAL_OVERRIDE_MODEL")
+			.numGPU(5) // Override only numGPU, leave others as default
+			.build();
+
+		var embeddingRequest = this.embeddingModel
+			.buildEmbeddingRequest(new EmbeddingRequest(List.of("Partial override"), requestOptions));
+		var ollamaRequest = this.embeddingModel.ollamaEmbeddingRequest(embeddingRequest);
+
+		assertThat(ollamaRequest.model()).isEqualTo("PARTIAL_OVERRIDE_MODEL");
+		assertThat(ollamaRequest.options().get("num_gpu")).isEqualTo(5);
+		assertThat(ollamaRequest.options().get("main_gpu")).isEqualTo(11);
+		assertThat(ollamaRequest.options().get("use_mmap")).isEqualTo(true);
+	}
+
+	@Test
+	public void ollamaEmbeddingRequestWithEmptyStringInput() {
+		// Test with list containing only empty string
+		var embeddingRequest = this.embeddingModel.buildEmbeddingRequest(new EmbeddingRequest(List.of(""), null));
+		var ollamaRequest = this.embeddingModel.ollamaEmbeddingRequest(embeddingRequest);
+
+		assertThat(ollamaRequest.input()).hasSize(1);
+		assertThat(ollamaRequest.input().get(0)).isEmpty();
+		assertThat(ollamaRequest.model()).isEqualTo("DEFAULT_MODEL");
+	}
+
 }