add tests for crowdsale contracts

test/helpers/advanceToBlock.js

@@ -0,0 +1,22 @@
+export function advanceBlock() {
+  return new Promise((resolve, reject) => {
+    web3.currentProvider.sendAsync({
+      jsonrpc: '2.0',
+      method: 'evm_mine',
+      id: Date.now(),
+    }, (err, res) => {
+      return err ? reject(err) : resolve(res)
+    })
+  })
+}
+
+// Advances the block number so that the last mined block is `number`.
+export default async function advanceToBlock(number) {
+  if (web3.eth.blockNumber > number) {
+    throw Error(`block number ${number} is in the past (current is ${web3.eth.blockNumber})`)
+  }
+
+  while (web3.eth.blockNumber < number) {
+    await advanceBlock()
+  }
+}