Add tests for some utility functions

test/util/utils.test.js

@@ -1,6 +1,8 @@
 import { expect } from 'chai';
+import Web3 from 'web3';
+import FakeProvider from 'web3-fake-provider';
 
-import { getMetamaskError } from '../../src/util/utils';
+import { getMetamaskError, signMessage, calculateCollateral } from '../../src/util/utils';
 
 describe('getMetamaskError', () => {
 
@@ -21,5 +23,44 @@ describe('getMetamaskError', () => {
 
     expect(actualErrorMessage).to.equals(expectedErrorMessage);
   });
+});
 
-})
+describe('signMessage', () => {
+  function getStubedWeb3(rawSignature) {
+    const fakeProvider = new FakeProvider();
+    const web3 = new Web3(fakeProvider);
+    fakeProvider.injectResult(rawSignature);
+    return web3;
+  }
+
+  it('should correctly extract [v, r, s] from signature', () => {
+    const rawSignature = '0x9955af11969a2d2a7f860cb00e6a00cfa7c581f5df2dbe8ea16700b33f4b4b9b69f945012f7ea7d3febf11eb1b78e1adc2d1c14c2cf48b25000938cc1860c83e01';
+    const web3 = getStubedWeb3(rawSignature);
+    const v = 28;
+    const r = '0x9955af11969a2d2a7f860cb00e6a00cfa7c581f5df2dbe8ea16700b33f4b4b9b';
+    const s = '0x69f945012f7ea7d3febf11eb1b78e1adc2d1c14c2cf48b25000938cc1860c83e';
+
+    const [ actualV, actualR, actualS] = signMessage(web3, '0xf204a4ef082f5c04bb89f7d5e6568b796096735a', 'This is my message :)');
+
+    expect(v, 'v not extracted correctly').to.equal(actualV);
+    expect(r, 'r not extracted correctly').to.equal(actualR);
+    expect(s, 's not extracted correctly').to.equal(actualS);
+  });
+});
+
+describe('calculateCollateral', () => {
+  [
+/* [priceFloor, priceCap, qtyMultiplier, qty,   price,    expectedCollateral] */
+    [20,          50,       2,            3,      10,        0],
+    [20,          50,       2,            3,      25,        30],
+    [20,          50,       2,            -3,     60,        0],
+    [20,          50,       2,            -3,     25,        150]
+  ].forEach((testCase) => {
+    it(`expects calculateCollateral(${testCase.slice(0, 5)}) to equal ${testCase[5]}`, () => {
+      const actualCollateral = calculateCollateral(...testCase);
+      const expectedCollateral = testCase[5];
+
+      expect(expectedCollateral).to.equal(actualCollateral);
+    });
+  });
+});