integrationTests: test built package on all supported node versions

Motivated by graphql#665

.eslintrc.yml

@@ -596,6 +596,9 @@ overrides:
       import/no-extraneous-dependencies: [error, { devDependencies: true }]
       import/no-nodejs-modules: off
       no-console: off
+  - files: 'integrationTests/*/**'
+    rules:
+      node/no-missing-require: off
   - files: 'resources/**'
     rules:
       node/no-unpublished-import: off

integrationTests/integration-test.js

@@ -31,4 +31,12 @@ describe('Integration Tests', () => {
     exec('npm install --silent', { cwd });
     exec('npm test', { cwd });
   }).timeout(40000);
+
+  it('Should work on all supported node versions', () => {
+    exec(`cp -R ${path.join(__dirname, 'node')} ${tmpDir}`);
+
+    const cwd = path.join(tmpDir, 'node');
+    exec('npm install', { cwd });
+    exec('npm test', { cwd });
+  }).timeout(40000);
 });

integrationTests/node/index.js

@@ -0,0 +1,45 @@
+'use strict';
+
+const assert = require('assert');
+
+const { buildSchema } = require('graphql');
+
+const { graphqlHTTP } = require('express-graphql');
+
+const schema = buildSchema('type Query { hello: String }');
+
+const middleware = graphqlHTTP({
+  graphiql: true,
+  schema,
+  rootValue: { hello: 'world' },
+});
+
+assert(typeof middleware === 'function');
+
+const request = {
+  url: 'http://example.com',
+  method: 'GET',
+  headers: {},
+  body: {
+    query: '{ hello }',
+  },
+};
+
+const response = {
+  headers: {},
+  setHeader(name, value) {
+    this.headers[name] = value;
+  },
+  text: null,
+  end(buffer) {
+    this.text = buffer.toString();
+  },
+};
+
+middleware(request, response).then(() => {
+  assert.deepStrictEqual(response.headers, {
+    'Content-Length': '26',
+    'Content-Type': 'application/json; charset=utf-8',
+  });
+  assert.deepStrictEqual(response.text, '{"data":{"hello":"world"}}');
+});

integrationTests/node/package.json

@@ -0,0 +1,12 @@
+{
+  "scripts": {
+    "test": "node test.js"
+  },
+  "dependencies": {
+    "express-graphql": "file:../express-graphql.tgz",
+    "graphql": "14.7.0",
+    "node-10": "npm:node@10.x.x",
+    "node-12": "npm:node@12.x.x",
+    "node-14": "npm:node@14.x.x"
+  }
+}

integrationTests/node/test.js

@@ -0,0 +1,17 @@
+'use strict';
+
+const path = require('path');
+const childProcess = require('child_process');
+
+const { dependencies } = require('./package.json');
+
+const nodeVersions = Object.keys(dependencies)
+  .filter((pkg) => pkg.startsWith('node-'))
+  .sort((a, b) => b.localeCompare(a));
+
+for (const version of nodeVersions) {
+  console.log(`Testing on ${version} ...`);
+
+  const nodePath = path.join(__dirname, 'node_modules', version, 'bin/node');
+  childProcess.execSync(nodePath + ' index.js', { stdio: 'inherit' });
+}