test: migrate from Mocha to Jest

.babelrc

@@ -9,6 +9,7 @@
           "targets": {
             "browsers": [
               "last 5 versions",
+              "ie 9",
               "defaults"
             ]
           },
@@ -26,6 +27,15 @@
           "modules": false
         }]
       ]
+    },
+    "test": {
+      "presets": [
+        ["env", {
+          "targets": {
+            "node": "current"
+          },
+        }]
+      ]
     }
   }
 }

.eslintrc

@@ -22,14 +22,14 @@
       "functions": "ignore",
     }],
     "prettier/prettier": ["error", {
-      "trailingComma": "es5",
+      "printWidth": 100,
       "singleQuote": true,
-      "printWidth": 80
+      "trailingComma": "es5",
     }],
     "no-plusplus": 0
   },
   "env": {
-    "mocha": true
+    "jest": true
   },
   "globals": {
     "fetch": true,

package.json

@@ -33,12 +33,11 @@
   "devDependencies": {
     "babel-cli": "^6.26.0",
     "babel-eslint": "^8.0.1",
+    "babel-jest": "^21.2.0",
     "babel-plugin-transform-object-rest-spread": "^6.26.0",
     "babel-polyfill": "^6.26.0",
     "babel-preset-env": "^1.6.1",
     "babel-register": "^6.26.0",
-    "chai": "^4.1.2",
-    "chai-as-promised": "^7.1.1",
     "cz-conventional-changelog": "^2.1.0",
     "eslint": "^4.10.0",
     "eslint-config-airbnb-base": "^12.1.0",
@@ -48,8 +47,7 @@
     "eslint-plugin-prettier": "^2.3.1",
     "fetch-mock": "^5.13.1",
     "form-data": "^2.3.1",
-    "mocha": "^3.1.1",
-    "nyc": "^10.1.2",
+    "jest": "^21.2.1",
     "prettier": "^1.7.4",
     "rimraf": "^2.6.2",
     "semantic-release": "^8.2.0"
@@ -59,25 +57,19 @@
       "path": "./node_modules/cz-conventional-changelog"
     }
   },
-  "nyc": {
-    "exclude": [
-      "**/tests/**",
-      "resources",
-      "node_modules"
-    ],
-    "reporter": [
-      "lcov",
-      "text"
+  "jest": {
+    "roots": [
+      "<rootDir>/src"
     ]
   },
   "scripts": {
     "build": "npm run build-lib && npm run build-es",
     "build-lib": "rimraf lib && BABEL_ENV=lib babel src -d lib",
     "build-es": "rimraf es && BABEL_ENV=es babel src -d es",
     "lint": "eslint src test *.js",
-    "coverage": "nyc npm run test:all",
-    "test": "BABEL_ENV=lib mocha --require test/mocha-bootload --compilers js:babel-register test/*.test.js test/**/*.test.js",
-    "test:all": "npm run lint && npm run test",
+    "coverage": "jest --coverage --maxWorkers 2",
+    "watch": "jest --watch",
+    "test": "npm run coverage && npm run lint",
     "semantic-release": "semantic-release pre && npm publish && semantic-release post"
   }
 }

test/fetchWithMiddleware.test.js → src/__tests__/fetchWithMiddleware.test.js

@@ -1,9 +1,8 @@
 /* eslint-disable no-param-reassign */
 
-import { assert } from 'chai';
 import fetchMock from 'fetch-mock';
-import fetchWithMiddleware from '../src/fetchWithMiddleware';
-import { mockReq as mockRelayReq } from './testutils';
+import fetchWithMiddleware from '../fetchWithMiddleware';
+import { mockReq as mockRelayReq } from '../__mocks__/mockReq';
 
 function createMockReq(reqId) {
   const relayRequest = mockRelayReq(reqId);
@@ -32,16 +31,14 @@ describe('fetchWithMiddleware', () => {
     fetchMock.restore();
   });
 
-  it('should make a successfull request without middlewares', () => {
+  it('should make a successfull request without middlewares', async () => {
     fetchMock.post('/graphql', { id: 1, data: { user: 123 } });
-    return assert.isFulfilled(
-      fetchWithMiddleware(createMockReq(1), []).then(data => {
-        assert.deepEqual(data, { user: 123 });
-      })
-    );
+
+    const data = await fetchWithMiddleware(createMockReq(1), []);
+    expect(data).toEqual({ user: 123 });
   });
 
-  it('should make a successfull request with middlewares', () => {
+  it('should make a successfull request with middlewares', async () => {
     const numPlus5 = next => req =>
       next(req).then(res => {
         res.json.data.num += 5;
@@ -54,13 +51,11 @@ describe('fetchWithMiddleware', () => {
       });
 
     fetchMock.post('/graphql', { id: 1, data: { num: 1 } });
-    return assert.isFulfilled(
-      fetchWithMiddleware(createMockReq(1), [
-        numPlus5,
-        numMultiply10, // should be first, when changing response
-      ]).then(data => {
-        assert.deepEqual(data, { num: 15 });
-      })
-    );
+
+    const data = await fetchWithMiddleware(createMockReq(1), [
+      numPlus5,
+      numMultiply10, // should be first, when changing response
+    ]);
+    expect(data).toEqual({ num: 15 });
   });
 });

src/__tests__/mutation.test.js

@@ -0,0 +1,69 @@
+import fetchMock from 'fetch-mock';
+import { RelayNetworkLayer } from '../';
+import { mockReq } from '../__mocks__/mockReq';
+
+describe('Mutation tests', () => {
+  const middlewares = [];
+  const rnl = new RelayNetworkLayer(middlewares);
+
+  beforeEach(() => {
+    fetchMock.restore();
+  });
+
+  it('should make a successfull mutation', async () => {
+    fetchMock.post('/graphql', { data: { ok: 1 } });
+    const req = mockReq();
+    await rnl.sendMutation(req);
+    expect(req.payload).toEqual({ response: { ok: 1 } });
+  });
+
+  it('should fail correctly on network failure', async () => {
+    fetchMock.mock({
+      matcher: '/graphql',
+      response: {
+        throws: new Error('Network connection error'),
+      },
+      method: 'POST',
+    });
+    const req1 = mockReq();
+    await rnl.sendMutation(req1);
+    expect(req1.error instanceof Error).toBeTruthy();
+    expect(/Network connection error/.test(req1.error.message)).toBeTruthy();
+  });
+
+  it('should handle error response', async () => {
+    fetchMock.mock({
+      matcher: '/graphql',
+      response: {
+        status: 200,
+        body: {
+          errors: [{ location: 1, message: 'major error' }],
+        },
+      },
+      method: 'POST',
+    });
+
+    const req1 = mockReq(1);
+    await rnl.sendMutation(req1);
+    expect(req1.error instanceof Error).toBeTruthy();
+  });
+
+  it('should handle server non-2xx errors', async () => {
+    fetchMock.mock({
+      matcher: '/graphql',
+
+      response: {
+        status: 500,
+        body: 'Something went completely wrong.',
+      },
+      method: 'POST',
+    });
+
+    const req1 = mockReq(1);
+    await rnl.sendMutation(req1);
+
+    expect(req1.error instanceof Error).toBeTruthy();
+    expect(req1.error.message).toEqual('Something went completely wrong.');
+    expect(req1.error.fetchResponse.status).toEqual(500);
+  });
+});

test/queries.test.js → src/__tests__/queries.test.js

@@ -1,7 +1,6 @@
-import { assert } from 'chai';
 import fetchMock from 'fetch-mock';
-import { RelayNetworkLayer } from '../src';
-import { mockReq } from './testutils';
+import { RelayNetworkLayer } from '../';
+import { mockReq } from '../__mocks__/mockReq';
 
 describe('Queries tests', () => {
   const middlewares = [];
@@ -11,20 +10,22 @@ describe('Queries tests', () => {
     fetchMock.restore();
   });
 
-  it('should make a successfull query', () => {
+  it('should make a successfull query', async () => {
     fetchMock.mock({
       matcher: '/graphql',
       response: {
         status: 200,
-        body: { data: {} },
+        body: { data: { ok: 1 } },
         sendAsJson: true,
       },
       method: 'POST',
     });
-    return assert.isFulfilled(rnl.sendQueries([mockReq()]));
+    const req = mockReq();
+    await rnl.sendQueries([req]);
+    expect(req.payload).toEqual({ response: { ok: 1 } });
   });
 
-  it('should fail correctly on network failure', () => {
+  it('should fail correctly on network failure', async () => {
     fetchMock.mock({
       matcher: '/graphql',
       response: {
@@ -33,15 +34,12 @@ describe('Queries tests', () => {
       method: 'POST',
     });
     const req1 = mockReq();
-    return assert.isFulfilled(
-      rnl.sendQueries([req1]).then(() => {
-        assert(req1.error instanceof Error);
-        assert(/Network connection error/.test(req1.error.message));
-      })
-    );
+    await rnl.sendQueries([req1]);
+    expect(req1.error instanceof Error).toBeTruthy();
+    expect(/Network connection error/.test(req1.error.message)).toBeTruthy();
   });
 
-  it('should handle error response', () => {
+  it('should handle error response', async () => {
     fetchMock.mock({
       matcher: '/graphql',
       response: {
@@ -54,14 +52,11 @@ describe('Queries tests', () => {
     });
 
     const req1 = mockReq(1);
-    return assert.isFulfilled(
-      rnl.sendQueries([req1]).then(() => {
-        assert(req1.error instanceof Error, 'should be an error');
-      })
-    );
+    await rnl.sendQueries([req1]);
+    expect(req1.error instanceof Error).toBeTruthy();
   });
 
-  it('should handle server non-2xx errors', () => {
+  it('should handle server non-2xx errors', async () => {
     fetchMock.mock({
       matcher: '/graphql',
       response: {
@@ -72,14 +67,13 @@ describe('Queries tests', () => {
     });
 
     const req1 = mockReq(1);
-    return assert.isFulfilled(rnl.sendQueries([req1])).then(() => {
-      assert(req1.error instanceof Error, 'should be an error');
-      assert.equal(req1.error.message, 'Something went completely wrong.');
-      assert.equal(req1.error.fetchResponse.status, 500);
-    });
+    await rnl.sendQueries([req1]);
+    expect(req1.error instanceof Error).toBeTruthy();
+    expect(req1.error.message).toEqual('Something went completely wrong.');
+    expect(req1.error.fetchResponse.status).toEqual(500);
   });
 
-  it('should fail on missing `data` property', () => {
+  it('should fail on missing `data` property', async () => {
     fetchMock.mock({
       matcher: '/graphql',
       response: {
@@ -89,9 +83,9 @@ describe('Queries tests', () => {
       },
       method: 'POST',
     });
-    return assert.isFulfilled(
-      rnl.sendQueries([mockReq()]),
-      /^Server response.data was missing/
-    );
+
+    const req = mockReq();
+    await rnl.sendQueries([req]);
+    expect(req.error.toString()).toMatch('Server response.data was missing');
   });
 });