Add tests for assertValidName

Tested with and without GRAPHQL_NO_NAME_WARNING in the environment.

Author: wincent

package.json

@@ -65,6 +65,7 @@
     "babel-plugin-transform-regenerator": "6.24.1",
     "chai": "3.5.0",
     "chai-json-equal": "0.0.1",
+    "chai-spies": "0.7.1",
     "chai-subset": "1.5.0",
     "coveralls": "2.13.1",
     "eslint": "3.19.0",

resources/mocha-bootload.js

@@ -8,8 +8,9 @@
  */
 
 var chai = require('chai');
-chai.use(require('chai-subset'));
 chai.use(require('chai-json-equal'));
+chai.use(require('chai-spies'));
+chai.use(require('chai-subset'));
 
 process.on('unhandledRejection', function (error) {
   console.error('Unhandled Promise Rejection:');

src/utilities/__tests__/assertValidName-test.js

@@ -7,10 +7,12 @@
  *  of patent rights can be found in the PATENTS file in the same directory.
  */
 
-import { describe, it } from 'mocha';
-import { expect } from 'chai';
+import { afterEach, beforeEach, describe, it } from 'mocha';
+import { default as chai, expect } from 'chai';
 import { formatWarning } from '../assertValidName';
 
+/* eslint-disable no-console */
+
 /**
  * Helper for dedenting indented template literals. This helps us to
  * keep the tests pretty.
@@ -41,6 +43,64 @@ function createErrorObject(message, stack) {
   return error;
 }
 
+describe('assertValidName()', () => {
+  let assertValidName;
+  let noNameWarning;
+  let warn;
+
+  beforeEach(() => {
+    noNameWarning = process.env.GRAPHQL_NO_NAME_WARNING;
+    delete process.env.GRAPHQL_NO_NAME_WARNING;
+    warn = console.warn;
+    console.warn = chai.spy();
+
+    // Make sure module-internal state is reset for each test.
+    delete require.cache[require.resolve('../assertValidName')];
+    assertValidName = require('../assertValidName').assertValidName;
+
+  });
+
+  afterEach(() => {
+    console.warn = warn;
+    if (noNameWarning === undefined) {
+      delete process.env.GRAPHQL_NO_NAME_WARNING;
+    } else {
+      process.env.GRAPHQL_NO_NAME_WARNING = noNameWarning;
+    }
+  });
+
+  it('warns against use of leading double underscores', () => {
+    assertValidName('__bad');
+    expect(console.warn).to.have.been.called.once();
+    expect(console.warn.__spy.calls[0][0]).to.match(/must not begin with/);
+  });
+
+  it('warns exactly once even in the presence of multiple violations', () => {
+    assertValidName('__bad');
+    assertValidName('__alsoBad');
+    expect(console.warn).to.have.been.called.once();
+  });
+
+  it('throws for non-strings', () => {
+    expect(() => assertValidName({})).to.throw(/Must be named/);
+  });
+
+  it('throws for names with invalid characters', () => {
+    expect(() => assertValidName('>--()-->')).to.throw(/Names must match/);
+  });
+
+  it('does not warn during introspection', () => {
+    assertValidName('__bad', true);
+    expect(console.warn).not.to.have.been.called();
+  });
+
+  it('does not warn when GRAPHQL_NO_NAME_WARNING is in effect', () => {
+    process.env.GRAPHQL_NO_NAME_WARNING = '1';
+    assertValidName('__bad', true);
+    expect(console.warn).not.to.have.been.called();
+  });
+});
+
 describe('formatWarning()', () => {
   it('formats given a Chrome-style stack property', () => {
     const chromeStack = dedent(`

yarn.lock

@@ -627,6 +627,10 @@ [email protected]:
   version "0.0.1"
   resolved "https://registry.yarnpkg.com/chai-json-equal/-/chai-json-equal-0.0.1.tgz#338fcbbdaec63349379c7c4278c8a28da3b141a1"
 
+chai-spies@^0.7.1:
+  version "0.7.1"
+  resolved "https://registry.yarnpkg.com/chai-spies/-/chai-spies-0.7.1.tgz#343d99f51244212e8b17e64b93996ff7b2c2a9b1"
+
 [email protected]:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/chai-subset/-/chai-subset-1.5.0.tgz#d03dbcfa8c9daad848643bbde4e63376b7882427"