scala - Scalatest 'DoubleTolerance' 中的错误？

Question

我遇到过失败的测试，据我所知，这些测试都应该通过。我在这里遗漏了一些明显的东西吗？

import org.scalatest._

class xxxTests extends FlatSpec with ShouldMatchers {
  import math.{Pi => PI}

  "" should "(this should pass)" in {
    assert( 0.0 === 0.0 )  // ok

    (1e-100) should equal ((0.0) plusOrMinus 1e-5)    // FAILS!!!  "1.0E-100 did not equal DoubleTolerance(0.0,1.0E-5)"
    (1e-3) should not equal ((0.0) plusOrMinus 1e-5)    // ok
    (0.0) should equal ((0.0) plusOrMinus 1e-5)    // FAILS!!!  "0.0 did not equal DoubleTolerance(0.0,1.0E-5)"
  }
}

我在 Scalatest 1.8 和 2.0M4 上都经历过这种情况。

Answer 1

问题:必须使用be ，不是 equal .

离开这里是我愚蠢的标志(嗯，注意力不集中)。

https://groups.google.com/forum/?fromgroups=#!msg/scalatest-users/pb54GzOej6I/C9714h_OW_UJ

You must use plusOrMinus with "be" not "equal". "equal" always compares for equality by invoking == on one object, passing in the other. "be" does different things depending on what object is being passed. So try:

0.5 must be (0.5 plusOrMinus 0.1)