Scan nested locations for GraphQL schema files

This commit changes the default value for the `spring.graphql.locations`
configuration property to `classpath:/graphql/**/`. By default, this
will scan nested locations for GraphQL schema files.

Fixes gh-210

graphql-spring-boot-starter/src/main/java/org/springframework/graphql/boot/GraphQlProperties.java

@@ -66,7 +66,7 @@ public class GraphQlProperties {
 		/**
 		 * Locations of GraphQL schema files.
 		 */
-		private String[] locations = new String[] { "classpath:graphql/"};
+		private String[] locations = new String[] { "classpath:graphql/**/"};
 
 		/**
 		 * File extensions for GraphQL schema files.

graphql-spring-boot-starter/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -2,7 +2,7 @@
   "properties": [
     {
       "name": "spring.graphql.schema.locations",
-      "defaultValue": "classpath:graphql/"
+      "defaultValue": "classpath:graphql/**/"
     },
     {
       "name": "spring.graphql.schema.file-extensions",

graphql-spring-boot-starter/src/test/java/org/springframework/graphql/boot/GraphQlAutoConfigurationTests.java

@@ -40,10 +40,11 @@ class GraphQlAutoConfigurationTests {
 
 	@Test
 	void shouldFailWhenSchemaFileIsMissing() {
-		this.contextRunner.run((context) -> {
-			assertThat(context).hasFailed();
-			assertThat(context).getFailure().getRootCause().isInstanceOf(MissingSchemaException.class);
-		});
+		this.contextRunner.withPropertyValues("spring.graphql.schema.locations:classpath:missing/")
+				.run((context) -> {
+					assertThat(context).hasFailed();
+					assertThat(context).getFailure().getRootCause().isInstanceOf(MissingSchemaException.class);
+				});
 	}
 
 	@Test
@@ -52,6 +53,11 @@ class GraphQlAutoConfigurationTests {
 				.run((context) -> assertThat(context).hasSingleBean(GraphQlSource.class));
 	}
 
+	@Test
+	void shouldScanNestedLocations() {
+		this.contextRunner.run((context) -> assertThat(context).hasSingleBean(GraphQlSource.class));
+	}
+
 	@Test
 	void shouldUseProgrammaticallyDefinedBuilder() {
 		this.contextRunner.withPropertyValues("spring.graphql.schema.locations:classpath:books/")

graphql-spring-boot-starter/src/test/resources/graphql/queries.graphqls

@@ -0,0 +1,3 @@
+type Query {
+    bookById(id: ID): Book
+}

graphql-spring-boot-starter/src/test/resources/graphql/types/book.graphqls

@@ -0,0 +1,5 @@
+type Book {
+    id: ID
+    name: String
+    pageCount: Int
+}