Add SDL schema generation test for graphql subgraph

gradle.properties

@@ -51,7 +51,7 @@ stdlibHttpVersion=2.10.0-20230911-204400-1c092fe
 stdlibWebsocketVersion=2.10.0-20230911-221500-317e2e7
 
 # Level 07
-stdlibGraphqlVersion=1.10.0-20230912-084000-2ef781d
+stdlibGraphqlVersion=1.10.0-20230912-160300-47e43f5
 
 # Ballerinax Observer
 observeVersion=1.2.0-20230911-133500-b3d8db3

graphql-cli/src/test/java/io/ballerina/graphql/cmd/SdlSchemaGenerationTest.java

@@ -254,6 +254,22 @@ public void testSdlGenerationWithDocumentation() {
         }
     }
 
+    @Test(description = "Test successful GraphQL command execution with graphql subgraph service")
+    public void testSdlGenerationForSubgraph() {
+        String[] args = {"-i", "valid/service_11.bal", "-o", this.tmpDir.toString()};
+        try {
+            executeCommand(args);
+            String fileName = "schema_product.graphql";
+            Assert.assertTrue(Files.exists(this.tmpDir.resolve(fileName)));
+            Path expectedSchemaFile = resourceDir.resolve(Paths.get("expectedSchemas", fileName));
+            String expectedSchema = readContentWithFormat(expectedSchemaFile);
+            String generatedSchema = readContentWithFormat(this.tmpDir.resolve(fileName));
+            Assert.assertEquals(expectedSchema, generatedSchema);
+        } catch (IOException | InterruptedException e) {
+            Assert.fail(e.toString());
+        }
+    }
+
     @Test(description = "Test GraphQL command execution with service includes compilation errors")
     public void testExecuteWithBalFileIncludeCompilationErrors() {
         String[] args = {"-i", "invalid/service_1.bal", "-o", this.tmpDir.toString()};

graphql-cli/src/test/resources/expectedSchemas/schema_product.graphql

@@ -0,0 +1,19 @@
+extend schema @link(url: "https://specs.apollo.dev/federation/v2.0", import: ["@key"]) 
+
+type Query {
+  product(id: String!): Product
+  products: [Product!]!
+}
+
+type Product @key(fields: "id") {
+  id: String!
+  title: String!
+  description: String!
+  price: Int!
+  category: Category!
+}
+
+type Category {
+  id: String!
+  title: String!
+}

graphql-cli/src/test/resources/graphqlServices/valid/service_11.bal

@@ -0,0 +1,72 @@
+// Copyright (c) 2023 WSO2 LLC. (http://www.wso2.org). All Rights Reserved.
+//
+// WSO2 LLC. licenses this file to you under the Apache License,
+// Version 2.0 (the "License"); you may not use this file except
+// in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import ballerina/graphql;
+import ballerina/graphql.subgraph;
+
+@subgraph:Entity {
+    key: "id",
+    resolveReference: resolveProduct
+}
+public type Product record {
+    string id;
+    string title;
+    string description;
+    int price;
+    Category category;
+};
+
+public type Category record {
+    string id;
+    string title;
+};
+
+function resolveProduct(subgraph:Representation representation) returns Product|error? {
+    string id = check representation["id"].ensureType();
+    return trap products.filter(product => product.id == id).pop();
+}
+
+@subgraph:Subgraph
+service /product on new graphql:Listener(4001) {
+    resource function get product(string id) returns Product? {
+        var product = products.filter(product => id == product.id);
+        if (product.length() > 0) {
+            return product[0];
+        }
+        return ();
+    }
+
+    resource function get products() returns Product[] {
+        return products;
+    }
+}
+
+Category[] categories = [
+    {
+        id: "1",
+        title: "Kitchen appliances"
+    }
+];
+
+Product[] products = [
+    {
+        id: "1",
+        title: "Knife",
+        description: "A knife is a tool with a cutting edge.",
+        price: 100,
+        category: categories[0]
+    }
+];