Add sdl download ability to client:download-schema

.gitignore

@@ -27,3 +27,6 @@ vscode-apollo-*.vsix
 # files generated from tests
 __tmp__*
 .vscode-test
+
+#idea folder
+.idea/

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - `apollo`
   - Shorten `client:check` and `service:check` output in CI [#1404](https://github.com/apollographql/apollo-tooling/pull/1404)
+  - Add `--target=format` flag to `client:download-schema` command to download schema in desired format i.e. SDL or JSON
 - `apollo-codegen-core`
   - <First `apollo-codegen-core` related entry goes here>
 - `apollo-codegen-flow`

packages/apollo/README.md

@@ -228,6 +228,8 @@ OPTIONS
 
   --tagName=tagName                      Name of the template literal tag used to identify template literals containing
                                          GraphQL queries in Javascript/Typescript code
+
+  --target=format                        Format of schema to be downloaded. Currenlty supporting SDL & JSON
 ```
 
 _See code: [src/commands/client/download-schema.ts](https://github.com/apollographql/apollo-tooling/blob/master/packages/apollo/src/commands/client/download-schema.ts)_

packages/apollo/src/commands/client/download-schema.ts

@@ -1,5 +1,5 @@
 import { flags } from "@oclif/command";
-import { introspectionFromSchema } from "graphql";
+import { introspectionFromSchema, printSchema } from "graphql";
 import { writeFileSync } from "fs";
 
 import { ClientCommand } from "../../Command";
@@ -8,32 +8,40 @@ export default class SchemaDownload extends ClientCommand {
   static description = "Download a schema from engine or a GraphQL endpoint.";
 
   static flags = {
-    ...ClientCommand.flags
+    ...ClientCommand.flags,
+
+    target: flags.string({
+      description:
+        "Format of schema to be downloaded i.e. JSON or SDL. Default is JSON"
+    })
   };
 
   static args = [
     {
       name: "output",
-      description: "Path to write the introspection result to",
-      required: true,
-      default: "schema.json"
+      description: "Path to write the introspection result to"
     }
   ];
 
   async run() {
     let result;
     let gitContext;
-    await this.runTasks(({ args, project, flags }) => [
-      {
-        title: `Saving schema to ${args.output}`,
-        task: async () => {
-          const schema = await project.resolveSchema({ tag: flags.tag });
-          writeFileSync(
-            args.output,
-            JSON.stringify(introspectionFromSchema(schema), null, 2)
-          );
+    await this.runTasks(({ args, project, flags }) => {
+      const isSDLFormat = flags.target && flags.target.toUpperCase() === "SDL";
+      const output =
+        args.output || (isSDLFormat ? "schema.graphql" : "schema.json");
+      return [
+        {
+          title: `Saving schema to ${output}`,
+          task: async () => {
+            const schema = await project.resolveSchema({ tag: flags.tag });
+            const formattedSchema = isSDLFormat
+              ? printSchema(schema)
+              : JSON.stringify(introspectionFromSchema(schema), null, 2);
+            writeFileSync(output, formattedSchema);
+          }
         }
-      }
-    ]);
+      ];
+    });
   }
 }