fix: Throw NonTransientAiException on syntax errors in prompt templates

spring-ai-client-chat/src/test/java/org/springframework/ai/prompt/PromptTemplateTest.java

@@ -31,6 +31,7 @@
 import org.springframework.ai.chat.prompt.ChatOptions;
 import org.springframework.ai.chat.prompt.Prompt;
 import org.springframework.ai.chat.prompt.PromptTemplate;
+import org.springframework.ai.retry.NonTransientAiException;
 import org.springframework.core.io.InputStreamResource;
 import org.springframework.core.io.Resource;
 
@@ -117,7 +118,7 @@ public void testRenderWithList() {
 		assertEqualsWithNormalizedEOLs(expected, message.getText());
 
 		PromptTemplate unfilledPromptTemplate = new PromptTemplate(templateString);
-		assertThatExceptionOfType(IllegalStateException.class).isThrownBy(unfilledPromptTemplate::render)
+		assertThatExceptionOfType(NonTransientAiException.class).isThrownBy(unfilledPromptTemplate::render)
 			.withMessage("Not all variables were replaced in the template. Missing variable names are: [items].");
 	}
 
@@ -202,7 +203,7 @@ public void testRenderFailure() {
 		PromptTemplate promptTemplate = PromptTemplate.builder().template(template).variables(model).build();
 
 		// Rendering the template with a missing key should throw an exception
-		assertThrows(IllegalStateException.class, promptTemplate::render);
+		assertThrows(NonTransientAiException.class, promptTemplate::render);
 	}
 
 }

spring-ai-client-chat/src/test/java/org/springframework/ai/prompt/PromptTests.java

@@ -26,6 +26,7 @@
 import org.springframework.ai.chat.prompt.Prompt;
 import org.springframework.ai.chat.prompt.PromptTemplate;
 import org.springframework.ai.chat.prompt.SystemPromptTemplate;
+import org.springframework.ai.retry.NonTransientAiException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -43,7 +44,7 @@ void newApiPlaygroundTests() {
 
 		// Try to render with missing value for template variable, expect exception
 		Assertions.assertThatThrownBy(() -> pt.render(model))
-			.isInstanceOf(IllegalStateException.class)
+			.isInstanceOf(NonTransientAiException.class)
 			.hasMessage("Not all variables were replaced in the template. Missing variable names are: [lastName].");
 
 		pt.add("lastName", "Park"); // TODO investigate partial

spring-ai-model/src/test/java/org/springframework/ai/chat/prompt/PromptTemplateBuilderTests.java

@@ -21,6 +21,7 @@
 
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
+import org.springframework.ai.retry.NonTransientAiException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
@@ -85,7 +86,7 @@ void renderWithMissingVariableShouldThrow() {
 			// If render() doesn't throw, fail the test
 			Assertions.fail("Expected IllegalStateException was not thrown.");
 		}
-		catch (IllegalStateException e) {
+		catch (NonTransientAiException e) {
 			// Assert that the message is exactly the expected string
 			assertThat(e.getMessage())
 				.isEqualTo("Not all variables were replaced in the template. Missing variable names are: [name].");

spring-ai-template-st/pom.xml

@@ -48,6 +48,12 @@
             <version>${project.parent.version}</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.ai</groupId>
+            <artifactId>spring-ai-retry</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
+
         <dependency>
             <groupId>org.antlr</groupId>
             <artifactId>ST4</artifactId>
@@ -74,4 +80,4 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
-</project>
+</project>

spring-ai-template-st/src/main/java/org/springframework/ai/template/st/StTemplateRenderer.java

@@ -24,6 +24,7 @@
 import org.antlr.runtime.TokenStream;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.ai.retry.NonTransientAiException;
 import org.stringtemplate.v4.ST;
 import org.stringtemplate.v4.compiler.Compiler;
 import org.stringtemplate.v4.compiler.STLexer;
@@ -115,7 +116,7 @@ private ST createST(String template) {
 			return new ST(template, this.startDelimiterToken, this.endDelimiterToken);
 		}
 		catch (Exception ex) {
-			throw new IllegalArgumentException("The template string is not valid.", ex);
+			throw new NonTransientAiException("The template string is not valid.", ex);
 		}
 	}
 
@@ -137,7 +138,7 @@ private Set<String> validate(ST st, Map<String, Object> templateVariables) {
 				logger.warn(VALIDATION_MESSAGE.formatted(missingVariables));
 			}
 			else if (this.validationMode == ValidationMode.THROW) {
-				throw new IllegalStateException(VALIDATION_MESSAGE.formatted(missingVariables));
+				throw new NonTransientAiException(VALIDATION_MESSAGE.formatted(missingVariables));
 			}
 		}
 		return missingVariables;

spring-ai-template-st/src/test/java/org/springframework/ai/template/st/StTemplateRendererTests.java

@@ -21,6 +21,7 @@
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.ai.retry.NonTransientAiException;
 import org.springframework.ai.template.ValidationMode;
 import org.springframework.test.util.ReflectionTestUtils;
 
@@ -107,7 +108,7 @@ void shouldThrowExceptionForInvalidTemplateSyntax() {
 		Map<String, Object> variables = new HashMap<>();
 		variables.put("name", "Spring AI");
 
-		assertThatThrownBy(() -> renderer.apply("Hello {name!", variables)).isInstanceOf(IllegalArgumentException.class)
+		assertThatThrownBy(() -> renderer.apply("Hello {name!", variables)).isInstanceOf(NonTransientAiException.class)
 			.hasMessageContaining("The template string is not valid.");
 	}
 
@@ -118,7 +119,7 @@ void shouldThrowExceptionForMissingVariablesInThrowMode() {
 		variables.put("greeting", "Hello");
 
 		assertThatThrownBy(() -> renderer.apply("{greeting} {name}!", variables))
-			.isInstanceOf(IllegalStateException.class)
+			.isInstanceOf(NonTransientAiException.class)
 			.hasMessageContaining(
 					"Not all variables were replaced in the template. Missing variable names are: [name]");
 	}