Merged latestTime, increaseTime and duration into a time helper. (#1364)

test/helpers/time.js

@@ -0,0 +1,62 @@
+const { ethGetBlock } = require('./web3');
+
+// Returns the time of the last mined block in seconds
+async function latest () {
+  const block = await ethGetBlock('latest');
+  return block.timestamp;
+}
+
+// Increases ganache time by the passed duration in seconds
+function increase (duration) {
+  const id = Date.now();
+
+  return new Promise((resolve, reject) => {
+    web3.currentProvider.sendAsync({
+      jsonrpc: '2.0',
+      method: 'evm_increaseTime',
+      params: [duration],
+      id: id,
+    }, err1 => {
+      if (err1) return reject(err1);
+
+      web3.currentProvider.sendAsync({
+        jsonrpc: '2.0',
+        method: 'evm_mine',
+        id: id + 1,
+      }, (err2, res) => {
+        return err2 ? reject(err2) : resolve(res);
+      });
+    });
+  });
+}
+
+/**
+ * Beware that due to the need of calling two separate ganache methods and rpc calls overhead
+ * it's hard to increase time precisely to a target point so design your test to tolerate
+ * small fluctuations from time to time.
+ *
+ * @param target time in seconds
+ */
+async function increaseTo (target) {
+  const now = (await latest());
+
+  if (target < now) throw Error(`Cannot increase current time(${now}) to a moment in the past(${target})`);
+  const diff = target - now;
+  return increase(diff);
+}
+
+const duration = {
+  seconds: function (val) { return val; },
+  minutes: function (val) { return val * this.seconds(60); },
+  hours: function (val) { return val * this.minutes(60); },
+  days: function (val) { return val * this.hours(24); },
+  weeks: function (val) { return val * this.days(7); },
+  years: function (val) { return val * this.days(365); },
+};
+
+module.exports = {
+  latest,
+  increase,
+  increaseTo,
+  duration,
+};