`evm_increaseTime` does not increase timestamp

Question

How can I fix this?

See:

$ truffle console
truffle(development)> web3.eth.getBlock("latest").timestamp
> 1506694386
truffle(development)> web3.currentProvider.send({jsonrpc: "2.0", method: "evm_increaseTime", params: [500000], id: 123})
{ id: 123, jsonrpc: '2.0', result: 500000 }
truffle(development)> web3.currentProvider.send({jsonrpc: "2.0", method: "evm_increaseTime", params: [500000], id: 123})
{ id: 123, jsonrpc: '2.0', result: 1000000 }

When using evm_increaseTime, the result returns a value that appends to 0, instead of adding onto the block time.

The expected result value should be 1506694386 + 500000, but instead, it returns 0 + 500000.

Your Environment

• Version used: v4.1.3
• Operating System and version: Mac OSX

---

EDIT: On the suggestion of force-mining:

If I mine a block before (or even after) performing evm_increaseTime, it does not make a difference:

$ truffle console
truffle(development)> web3.eth.getBlock("latest").timestamp
1506739091
truffle(development)> web3.currentProvider.send({jsonrpc: "2.0", method: "evm_mine", params: [], id: 0})
{ id: 0, jsonrpc: '2.0', result: [] }
truffle(development)> web3.eth.getBlock("latest").timestamp
1506739124
truffle(development)> web3.eth.getBlock("latest").timestamp
1506739124
truffle(development)> web3.currentProvider.send({jsonrpc: "2.0", method: "evm_increaseTime", params: [500000], id: 123})
{ id: 123, jsonrpc: '2.0', result: 500000 }
truffle(development)> web3.currentProvider.send({jsonrpc: "2.0", method: "evm_mine", params: [], id: 0})
{ id: 0, jsonrpc: '2.0', result: [] }
truffle(development)> web3.currentProvider.send({jsonrpc: "2.0", method: "evm_increaseTime", params: [500000], id: 123})
{ id: 123, jsonrpc: '2.0', result: 1000000 }

Answer 1

Looking at the testrpc docs https://github.com/ethereumjs/testrpc :

evm_increaseTime : Jump forward in time. Takes one parameter, which is the amount of time to increase in seconds. Returns the total time adjustment, in seconds.

So it's normal that the first call you make returns 500000 and the second call returns the total time adjustment 500000 + 500000 = 1000000.

To make those adjustments effective you need to force a block to be mined after you've ran evm_increaseTime :

web3.currentProvider.send({jsonrpc: "2.0", method: "evm_mine", params: [], id: 0})

afterwards you can check the current timestamp with:

web3.eth.getBlock(web3.eth.blockNumber).timestamp

Answer 2

result field in response to evm_increaseTime call contains timestamp adjustment, not timestamp of the next block.

Check the source code:

BlockchainDouble.prototype.increaseTime = function(seconds) {
  if (seconds < 0) seconds = 0;
  this.timeAdjustment += seconds;
  return this.timeAdjustment;
};