From f3573f359d17bd6fa3e4f42b66e722c49d13af95 Mon Sep 17 00:00:00 2001
From: Oleg Zhurakousky <ozhurakousky@vmware.com>
Date: Mon, 8 Feb 2021 10:36:00 +0100
Subject: [PATCH] GH-639 Fix NPE for when using Supplier with AWS API Gateway

Resolves #639
---
 .../function/adapter/aws/AWSLambdaUtils.java  |  2 +-
 .../adapter/aws/FunctionInvokerTests.java     | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/AWSLambdaUtils.java b/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/AWSLambdaUtils.java
index e74034776..5ed017389 100644
--- a/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/AWSLambdaUtils.java
+++ b/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/AWSLambdaUtils.java
@@ -202,7 +202,7 @@ final class AWSLambdaUtils {
 	}
 
 	private static boolean isTypeAnApiGatewayRequest(Type type) {
-		return isAPIGatewayProxyRequestEventPresent()
+		return type != null && isAPIGatewayProxyRequestEventPresent()
 				? type.getTypeName().endsWith(APIGatewayProxyRequestEvent.class.getSimpleName())
 				: false;
 	}
diff --git a/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/test/java/org/springframework/cloud/function/adapter/aws/FunctionInvokerTests.java b/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/test/java/org/springframework/cloud/function/adapter/aws/FunctionInvokerTests.java
index 0e642a127..fbfeffe8a 100644
--- a/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/test/java/org/springframework/cloud/function/adapter/aws/FunctionInvokerTests.java
+++ b/spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/test/java/org/springframework/cloud/function/adapter/aws/FunctionInvokerTests.java
@@ -23,6 +23,7 @@ import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.function.Consumer;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
 import com.amazonaws.services.lambda.runtime.events.KinesisEvent;
@@ -625,6 +626,22 @@ public class FunctionInvokerTests {
 		assertThat(result.get("body")).isEqualTo("\"hello\"");
 	}
 
+	@SuppressWarnings("rawtypes")
+	@Test
+	public void testApiGatewayAsSupplier() throws Exception {
+		System.setProperty("MAIN_CLASS", ApiGatewayConfiguration.class.getName());
+		System.setProperty("spring.cloud.function.definition", "supply");
+		FunctionInvoker invoker = new FunctionInvoker();
+
+		InputStream targetStream = new ByteArrayInputStream(this.apiGatewayEvent.getBytes());
+		ByteArrayOutputStream output = new ByteArrayOutputStream();
+		invoker.handleRequest(targetStream, output, null);
+
+		Map result = mapper.readValue(output.toByteArray(), Map.class);
+		System.out.println(result);
+		assertThat(result.get("body")).isEqualTo("\"boom\"");
+	}
+
 	@SuppressWarnings("rawtypes")
 	@Test
 	public void testApiGatewayEventAsMessage() throws Exception {
@@ -840,6 +857,12 @@ public class FunctionInvokerTests {
 	@Configuration
 	public static class ApiGatewayConfiguration {
 
+		@Bean
+		public Supplier<String> supply() {
+			return () -> "boom";
+		}
+
+
 		@Bean
 		public Consumer<String> consume() {
 			return v -> System.out.println(v);