Print Schema Tool

This tool accepts an input graphql schema definition file and
outputs the corresponding introspection query result for that file

Author: schrockn-zz

src/language/schema/__tests__/materializer.js

@@ -4,16 +4,15 @@
  *
  *  This source code is licensed under the BSD-style license found in the
  *  LICENSE file in the root directory of this source tree. An additional grant
-*  of patent rights can be found in the PATENTS file in the same directory.
+ *  of patent rights can be found in the PATENTS file in the same directory.
  */
 
 import { expect } from 'chai';
 import { describe, it } from 'mocha';
 import { parseSchema } from '../parser';
 import { materializeSchema } from '../materializer';
 import { printSchema } from '../../../type/printer';
-import { introspectionQuery } from '../../../type/introspectionQuery';
-import { graphql } from '../../../';
+import { getIntrospectionResult } from '../printer';
 
 // 80+ char lines are useful in describe/it, so ignore in this file.
 /*eslint-disable max-len */
@@ -23,9 +22,7 @@ function printForTest(result) {
 }
 
 async function getOutput(body, queryType) {
-  var doc = parseSchema(body);
-  var schema = materializeSchema(doc, queryType);
-  var result = await graphql(schema, introspectionQuery);
+  var result = await getIntrospectionResult(body, queryType);
   return await printForTest(result);
 }
 
@@ -272,6 +269,6 @@ type Hello {
 }
 `;
     var doc = parseSchema(body);
-    expect(() => materializeSchema(doc, 'Wat')).to.throw('Type Wat not found in document');
+    expect(() => materializeSchema(doc, 'Wat')).to.throw('Specified query type Wat not found in document');
   });
 });

src/language/schema/materializer.js

@@ -111,6 +111,11 @@ export function materializeSchema(
 
   var astMap = makeDict(ast.definitions, d => d.name.value);
 
+  if (nullish(astMap[queryTypeName])) {
+    throw new Error('Specified query type ' + queryTypeName +
+      ' not found in document.');
+  }
+
   /**
    * This generates a function that allows you to produce
    * type definitions on demand. We produce the function

src/language/schema/printer.js

@@ -0,0 +1,19 @@
+/**
+ *  Copyright (c) 2015, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+import { parseSchema } from './parser';
+import { materializeSchema } from './materializer';
+import { introspectionQuery } from './../../type/introspectionQuery';
+import { graphql } from '../../';
+
+export async function getIntrospectionResult(body, queryType) {
+  var doc = parseSchema(body);
+  var schema = materializeSchema(doc, queryType);
+  return await graphql(schema, introspectionQuery);
+}

src/tools/print-schema/print-schema.js

@@ -0,0 +1,14 @@
+/**
+ *  Copyright (c) 2015, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+require('babel/register')({
+  optional: ['runtime', 'es7.asyncFunctions']
+});
+
+require('./src').executeTool();

src/tools/print-schema/src/index.js

@@ -0,0 +1,57 @@
+/**
+ *  Copyright (c) 2015, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+import { getIntrospectionResult }
+  from '../../../../src/language/schema/printer';
+
+var Promise = require('bluebird');
+var parseArgs = require('minimist');
+var fs = require('fs');
+
+Promise.promisifyAll(fs);
+
+export async function executeTool() {
+  try {
+    var argDict = parseArgs(process.argv.slice(2));
+
+    if (argDict['?'] !== undefined || argDict.help !== undefined) {
+      console.log(helpString);
+      process.exit(0);
+    }
+
+    if (argDict.query === undefined) {
+      console.log('--query is required');
+      console.log(helpString);
+      process.exit(0);
+    }
+
+    if (argDict.file === undefined) {
+      console.log('--file is required');
+      console.log(helpString);
+      process.exit(0);
+    }
+
+    var body = await fs.readFileAsync(argDict.file);
+    var result = await getIntrospectionResult(body, argDict.query);
+    var out = await JSON.stringify(result, null, 2);
+    console.log(out);
+  } catch (error) {
+    console.error(error);
+    console.error(error.stack);
+  }
+}
+
+var helpString = `
+This tool consumes GraphQL schema definition files and outputs the
+introspection query result from querying that schema.
+
+Required:
+
+--file <path>: The path to the input schema definition file.
+--query <queryType>: The query type (root type) of the schema.`;