Remove chai autoinstall (#18)

* No longer install chai.should in setup.

* Update integration tests.

* Improve readme.

* Fix linter errors.

* Improve integration test scripts.

* Make chai a peerDependency.

* Add chai dev dependency.

README.md

@@ -14,28 +14,35 @@ npm install --save-dev openzeppelin-test-helpers
 ## Usage
 
 ```javascript
+// Import all required modules from openzeppelin-test-helpers
 const { BN, constants, expectEvent, shouldFail } = require('openzeppelin-test-helpers');
 
+// Import preferred chai flavor: both expect and should are supported
+const { expect } = require('chai');
+
 const ERC20 = artifacts.require('ERC20');
 
 contract('ERC20', ([sender, receiver]) => {
   beforeEach(async function () {
     this.erc20 = await ERC20.new();
-    this.value = new BN(1);
+    this.value = new BN(1); // The bundled BN library is the same one truffle and web3 use under the hood
   });
 
   it('reverts when transferring tokens to the zero address', async function () {
+    // Edge cases that trigger a require statement can be tested for, optionally checking the revert reason as well
     await shouldFail.reverting(this.erc20.transfer(constants.ZERO_ADDRESS, this.value, { from: sender }));
   });
 
   it('emits a Transfer event on successful transfers', async function () {
     const { logs } = this.erc20.transfer(receiver, this.value, { from: sender });
+    // Log-checking will not only look at the event name, but also the values, which can be addresses, strings, numbers, etc.
     expectEvent.inLogs(logs, 'Transfer', { from: sender, to: receiver, value: this.value });
   });
 
   it('updates balances on successful transfers', async function () {
     this.erc20.transfer(receiver, this.value, { from: sender });
-    (await this.token.balanceOf(receiver)).should.be.bignumber.equal(this.value);
+    // chai-bn is installed, which means BN values can be tested and compared using the bignumber property in chai
+    expect(await this.token.balanceOf(receiver)).to.be.bignumber.equal(this.value);
   });
 });
 ```

openzeppelin-test-helpers.js

@@ -1,15 +1,13 @@
-const { BN, expect, should } = require('./src/setup');
+const { BN } = require('./src/setup');
 
 module.exports = {
   balance: require('./src/balance'),
   BN,
   constants: require('./src/constants'),
   ether: require('./src/ether'),
-  expect,
   expectEvent: require('./src/expectEvent'),
   makeInterfaceId: require('./src/makeInterfaceId'),
   send: require('./src/send'),
-  should,
   shouldFail: require('./src/shouldFail'),
   singletons: require('./src/singletons'),
   time: require('./src/time'),

package.json

@@ -33,13 +33,13 @@
   "homepage": "https://github.com/OpenZeppelin/openzeppelin-test-helpers#readme",
   "dependencies": {
     "ansi-colors": "^3.2.3",
-    "chai": "^4.2.0",
     "chai-bn": "^0.1.1",
     "ethjs-abi": "^0.2.1",
     "semver": "^5.6.0",
     "truffle-contract": "^4.0.8"
   },
   "devDependencies": {
+    "chai": "^4.2.0",
     "eslint": "^5.9.0",
     "eslint-config-standard": "^12.0.0",
     "eslint-plugin-import": "^2.14.0",
@@ -49,5 +49,8 @@
     "eslint-plugin-standard": "^4.0.0",
     "ganache-cli": "^6.2.5",
     "truffle": "^5.0.1"
+  },
+  "peerDependencies": {
+    "chai": "^4.2.0"
   }
 }

src/expectEvent.js

@@ -1,4 +1,5 @@
-const { BN, expect } = require('./setup');
+const { BN } = require('./setup');
+const { expect } = require('chai');
 
 function inLogs (logs, eventName, eventArgs = {}) {
   const events = logs.filter(e => e.event === eventName);
@@ -35,7 +36,7 @@ async function inTransaction (txHash, emitter, eventName, eventArgs = {}) {
 }
 
 function contains (args, key, value) {
-  (key in args).should.equal(true, `Unknown event argument '${key}'`);
+  expect(key in args).to.equal(true, `Unknown event argument '${key}'`);
 
   if (value === null) {
     expect(args[key]).to.equal(null);

src/setup.js

@@ -1,13 +1,8 @@
 const chai = require('chai');
-
 const BN = web3.utils.BN;
 
-const should = chai
-  .use(require('chai-bn')(BN))
-  .should();
+chai.use(require('chai-bn')(BN));
 
 module.exports = {
   BN,
-  expect: chai.expect,
-  should,
 };

src/shouldFail.js

@@ -1,4 +1,4 @@
-const { should } = require('./setup');
+const { expect } = require('chai');
 const colors = require('ansi-colors');
 const semver = require('semver');
 
@@ -7,12 +7,12 @@ async function shouldFailWithMessage (promise, message) {
     await promise;
   } catch (error) {
     if (message) {
-      error.message.should.include(message, `Wrong failure type, expected '${message}'`);
+      expect(error.message).to.include(message, `Wrong failure type, expected '${message}'`);
     }
     return;
   }
 
-  should.fail('Expected failure not received');
+  expect.fail('Expected failure not received');
 }
 
 async function reverting (promise) {

src/singletons.js

@@ -1,5 +1,3 @@
-require('./setup');
-
 const ether = require('./ether');
 const send = require('./send');
 

test-integration/ganache-core-2.1.x/package.json

@@ -9,7 +9,9 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
-    "truffle": "^5.0.1",
-    "ganache-cli": "6.1.0"
-  }
+    "chai": "^4.2.0",
+    "ganache-cli": "6.1.0",
+    "truffle": "^5.0.1"
+  },
+  "dependencies": {}
 }

test-integration/ganache-core-2.1.x/test.sh

@@ -3,7 +3,10 @@
 # Delete the installed dependency
 rm -rf node_modules/openzeppelin-test-helpers
 # Replace it with the local package
-ln -s ../../.. node_modules/openzeppelin-test-helpers
+mkdir -p node_modules/openzeppelin-test-helpers/src
+cp -r ../../openzeppelin-test-helpers.js node_modules/openzeppelin-test-helpers/
+cp -r ../../package.json node_modules/openzeppelin-test-helpers/
+cp -r ../../src/* node_modules/openzeppelin-test-helpers/src/
 
 # Exit script as soon as a command fails.
 set -o errexit

test-integration/ganache-core-2.1.x/test/Tested.test.js

@@ -1,4 +1,5 @@
 const { shouldFail } = require('openzeppelin-test-helpers');
+const { expect } = require('chai');
 
 const Tested = artifacts.require('Tested');
 
@@ -14,13 +15,13 @@ contract('Tested', function (accounts) {
         const expectedMessage = 'lorem ipsum';
         // Asserting that locally installed ganache-core is v2.1.0.
         const nodeInfo = await web3.eth.getNodeInfo();
-        nodeInfo.should.include('2.1.0');
+        expect(nodeInfo).to.include('2.1.0');
         try {
           await this.contract.failWithRevertReason();
         }
         catch (error) {
           // Asserting that older ganache does NOT return reason message.
-          error.message.should.not.include(expectedMessage);
+          expect(error.message).to.not.include(expectedMessage);
         }
         // With that said, following revert should be accepted without regard to the specified
         // reason message.

test-integration/simple-project-truffle-5.x/package.json

@@ -9,6 +9,7 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
+    "chai": "^4.2.0",
     "truffle": "^5.0.1"
   }
 }

test-integration/simple-project-truffle-5.x/test.sh

@@ -2,7 +2,11 @@
 
 # Delete the installed dependency
 rm -rf node_modules/openzeppelin-test-helpers
+
 # Replace it with the local package
-ln -s ../../.. node_modules/openzeppelin-test-helpers
+mkdir -p node_modules/openzeppelin-test-helpers/src
+cp -r ../../openzeppelin-test-helpers.js node_modules/openzeppelin-test-helpers/
+cp -r ../../package.json node_modules/openzeppelin-test-helpers/
+cp -r ../../src/* node_modules/openzeppelin-test-helpers/src/
 
 npx truffle test

test-integration/simple-project-truffle-5.x/test/accounts.test.js

@@ -1,10 +1,11 @@
 const { balance, BN, ether, send } = require('openzeppelin-test-helpers');
+const { expect } = require('chai');
 
 contract('accounts', function (accounts) {
   it('sends ether and tracks balances', async function () {
     const value = ether('42', 'ether');
     const tracker = await balance.tracker(accounts[0]);
     await send.ether(accounts[0], accounts[1], value);
-    (await tracker.delta()).should.be.bignumber.equals(value.neg());
+    expect(await tracker.delta()).to.be.bignumber.equals(value.neg());
   });
 });

test/src/balance.test.js

@@ -1,4 +1,5 @@
 require('../../src/setup');
+const { expect } = require('chai');
 
 const balance = require('../../src/balance');
 const send = require('../../src/send');
@@ -7,48 +8,48 @@ const ether = require('../../src/ether');
 contract('balance', function ([sender, receiver]) {
   describe('current', function () {
     it('returns the current balance of an account as a BN', async function () {
-      (await balance.current(sender)).should.be.bignumber.equal(await web3.eth.getBalance(sender));
+      expect(await balance.current(sender)).to.be.bignumber.equal(await web3.eth.getBalance(sender));
     });
   });
 
   describe('balance tracker', function () {
     it('returns current balance ', async function () {
       const tracker = await balance.tracker(receiver);
-      (await tracker.get()).should.be.bignumber.equal(await web3.eth.getBalance(receiver));
+      expect(await tracker.get()).to.be.bignumber.equal(await web3.eth.getBalance(receiver));
     });
 
     it('get() adds a new checkpoint ', async function () {
       const tracker = await balance.tracker(sender);
       await send.ether(sender, receiver, ether('1'));
       await tracker.get();
-      (await tracker.delta()).should.be.bignumber.equal('0');
+      expect(await tracker.delta()).to.be.bignumber.equal('0');
     });
 
     it('returns correct deltas after get() checkpoint', async function () {
       const tracker = await balance.tracker(receiver);
       await send.ether(sender, receiver, ether('1'));
       await tracker.get();
       await send.ether(sender, receiver, ether('1'));
-      (await tracker.delta()).should.be.bignumber.equal(ether('1'));
+      expect(await tracker.delta()).to.be.bignumber.equal(ether('1'));
     });
 
     it('returns balance increments', async function () {
       const tracker = await balance.tracker(receiver);
       await send.ether(sender, receiver, ether('1'));
-      (await tracker.delta()).should.be.bignumber.equal(ether('1'));
+      expect(await tracker.delta()).to.be.bignumber.equal(ether('1'));
     });
 
     it('returns balance decrements', async function () {
       const tracker = await balance.tracker(sender);
       await send.ether(sender, receiver, ether('1'));
-      (await tracker.delta()).should.be.bignumber.equal(ether('-1'));
+      expect(await tracker.delta()).to.be.bignumber.equal(ether('-1'));
     });
 
     it('returns consecutive deltas', async function () {
       const tracker = await balance.tracker(sender);
       await send.ether(sender, receiver, ether('1'));
       await tracker.delta();
-      (await tracker.delta()).should.be.bignumber.equal('0');
+      expect(await tracker.delta()).to.be.bignumber.equal('0');
     });
   });
 });

test/src/ether.test.js

@@ -1,12 +1,13 @@
 const { BN } = require('../../src/setup');
+const { expect } = require('chai');
 const ether = require('../../src/ether');
 
 describe('ether', function () {
   it('returns a BN', function () {
-    ether('1').should.be.bignumber.equal(new BN('1000000000000000000'));
+    expect(ether('1')).to.be.bignumber.equal(new BN('1000000000000000000'));
   });
 
   it('works with negative amounts', function () {
-    ether('-1').should.be.bignumber.equal(new BN('-1000000000000000000'));
+    expect(ether('-1')).to.be.bignumber.equal(new BN('-1000000000000000000'));
   });
 });