const should = require('chai')
  .should();

async function expectThrow (promise, message) {
  try {
    await promise;
  } catch (error) {
    // Message is an optional parameter here
    if (message) {
      error.message.should.include(message, 'Expected \'' + message + '\', got \'' + error + '\' instead');
      return;
    } else {
      // TODO: Check jump destination to destinguish between a throw
      //       and an actual invalid jump.
      // TODO: When we contract A calls contract B, and B throws, instead
      //       of an 'invalid jump', we get an 'out of gas' error. How do
      //       we distinguish this from an actual out of gas event? (The
      //       ganache log actually show an 'invalid jump' event.)
      error.message.should.match(/[invalid opcode|out of gas|revert]/, 'Expected throw, got \'' + error + '\' instead');
      return;
    }
  }
  should.fail('Expected throw not received');
}

module.exports = {
  expectThrow,
};