feat(core): add support for loading GraphQL schema from js export file

README.md

@@ -69,17 +69,18 @@ CLI usage is as follow:
 
 Allowed flags:    
 
-| Flag Name       | Type     | Description                                                                            |
-|-----------------|----------|----------------------------------------------------------------------------------------|
-| -f,--file       | String   | Introspection JSON file, must provide file or URL flag                                 |
-| -u,--url        | String   | GraphQL server endpoint to fetch the introspection from, must provide URL or file flag |
-| -h,--header     | String   | Header to add to the introspection HTTP request when using --url  |
-| -t,--template   | String   | Template name, for example: "typescript"                                               |
-| -o,--out        | String   | Path for output file/directory. When using single-file generator specify filename, and when using multiple-files generator specify a directory                                     |
-| -nm,--no-model  | void     | If specified, server side schema won't be generated through the template (enums won't omit) |
-| -nd,--no-documents  | void     | If specified, client side documents won't be generated through the template |
-| -d,--dev        | void     | Turns ON development mode - prints output to console instead of files                  |
-| documents...    | [String] | Space separated paths of `.graphql` files or code files (glob path is supported) that contains GraphQL documents inside strings, or with `gql` tag (JavaScript), this field is optional - if no documents specified, only server side schema types will be generated                           |
+| Flag Name          | Type     | Description                                                                            |
+|--------------------|----------|----------------------------------------------------------------------------------------|
+| -f,--file          | String   | Introspection JSON file, must provide file or URL flag                                 |
+| -u,--url           | String   | GraphQL server endpoint to fetch the introspection from, must provide URL or file flag |
+| -e,--export        | String   | Path to a JavaScript (es5/6) file that exports (as default export) your `GraphQLSchema` object |
+| -h,--header        | String   | Header to add to the introspection HTTP request when using --url  |
+| -t,--template      | String   | Template name, for example: "typescript"                                               |
+| -o,--out           | String   | Path for output file/directory. When using single-file generator specify filename, and when using multiple-files generator specify a directory                                     |
+| -m,--no-schema     | void     | If specified, server side schema won't be generated through the template (enums won't omit) |
+| -c,--no-documents  | void     | If specified, client side documents won't be generated through the template |
+| -d,--dev           | void     | Turns ON development mode - prints output to console instead of files                  |
+| documents...       | [String] | Space separated paths of `.graphql` files or code files (glob path is supported) that contains GraphQL documents inside strings, or with `gql` tag (JavaScript), this field is optional - if no documents specified, only server side schema types will be generated                           |
 
 **Usage examples:***
 

dev-test/githunt/schema-export.js

@@ -0,0 +1,15 @@
+const GraphQL = require('graphql');
+
+module.exports = new GraphQL.GraphQLSchema({
+  query: new GraphQL.GraphQLObjectType({
+    name: 'RootQueryType',
+    fields: {
+      hello: {
+        type: GraphQL.GraphQLString,
+        resolve() {
+          return 'world';
+        }
+      }
+    }
+  })
+});

package.json

@@ -15,7 +15,7 @@
     "debug": "cd dist && node --inspect --debug-brk gql-gen.js",
     "changelog": "conventional-changelog -p angular -i CHANGELOG.md -s",
     "create-git-tag": "git tag $(cat package.json | $(npm bin)/json version)",
-    "dev": "cd dist && nodemon --ext ts,js,d.ts,template,graphql,json,handlebars gql-gen.js --dev --file ../dev-test/githunt/schema.json --template ts --out ../dev-test/githunt/typings.d.ts",
+    "dev": "cd dist && nodemon --ext ts,js,d.ts,template,graphql,json,handlebars gql-gen.js --dev --export ../dev-test/githunt/schema-export.js --template ts --out ../dev-test/githunt/typings.d.ts",
     "prepare": "npm run build && npm run test && npm run create-git-tag && git push && git push --tags",
     "test": "jest"
   },

src/cli.ts

@@ -4,6 +4,7 @@ import {introspectionFromUrl} from './introspection-from-url';
 import {introspectionFromFile} from './introspection-from-file';
 import {documentsFromGlobs} from './documents-glob';
 import {getTemplateGenerator} from './template-loader';
+import {introspectionFromExport} from './introspection-from-export';
 
 function collect(val, memo) {
   memo.push(val);
@@ -17,10 +18,11 @@ export const initCLI = (args): commander.IExportedCommand => {
     .option('-d, --dev', 'Turn on development mode - prints results to console')
     .option('-f, --file <filePath>', 'Parse local GraphQL introspection JSON file')
     .option('-u, --url <graphql-endpoint>', 'Parse remote GraphQL endpoint as introspection file')
+    .option('-u, --export <export-file>', 'Path to a JavaScript (es5/6) file that exports (as default export) your `GraphQLSchema` object')
     .option('-h, --header [header]', 'Header to add to the introspection HTTP request when using --url', collect, [])
     .option('-t, --template <template-name>', 'Language/platform name templates')
-    .option('-nm, --no-schema', 'Generates only client side documents, without server side schema types')
-    .option('-nd, --no-documents', 'Generates only server side schema types, without client side documents')
+    .option('-m, --no-schema', 'Generates only client side documents, without server side schema types')
+    .option('-c, --no-documents', 'Generates only server side schema types, without client side documents')
     .option('-o, --out <path>', 'Output file(s) path', String, './')
     .arguments('<options> [documents...]')
     .parse(args);
@@ -42,11 +44,12 @@ export const cliError = (err: string) => {
 export const validateCliOptions = (options) => {
   const file = options['file'];
   const url = options['url'];
+  const fsExport = options['export'];
   const template = options['template'];
   const out = options['out'];
 
-  if (!file && !url) {
-    cliError('Please specify one of --file or --url flags!');
+  if (!file && !url && !fsExport) {
+    cliError('Please specify one of --file, --url or --export flags!');
   }
 
   if (!template) {
@@ -57,6 +60,7 @@ export const validateCliOptions = (options) => {
 export const transformOptions = (options): Promise<TransformedOptions> => {
   const file: string = options['file'];
   const url: string = options['url'];
+  const fsExport: string = options['export'];
   const documents: string[] = options['args'] || [];
   const template: string = options['template'];
   const out: string = options['out'];
@@ -77,6 +81,10 @@ export const transformOptions = (options): Promise<TransformedOptions> => {
   else if (url) {
     introspectionPromise = introspectionFromUrl(url, headers);
   }
+  else if (fsExport) {
+    introspectionPromise = introspectionFromExport(fsExport);
+  }
+
 
   const documentsPromise = documentsFromGlobs(documents);
   const generatorTemplatePromise = getTemplateGenerator(template);

src/introspection-from-export.ts

@@ -0,0 +1,27 @@
+import * as fs from 'fs';
+import {IntrospectionQuery} from 'graphql/utilities/introspectionQuery';
+import {GraphQLSchema} from 'graphql/type/schema';
+import { graphql, introspectionQuery } from 'graphql';
+
+export const introspectionFromExport = (file: string) => {
+  return new Promise<IntrospectionQuery>((resolve, reject) => {
+    if (fs.existsSync(file)) {
+      try {
+        const schema = require(file);
+
+        if (schema && schema instanceof GraphQLSchema) {
+          resolve(graphql(schema, introspectionQuery).then(res => res.data));
+        }
+        else {
+          reject(new Error(`Invalid export from export file ${file}, make sure to default export your GraphQLSchema object!`));
+        }
+      }
+      catch (e) {
+        reject(e);
+      }
+    }
+    else {
+      reject(`Unable to locate introspection export file: ${file}`);
+    }
+  });
+};