Utils/tests/Expect/approxEquals_A04_t01.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion static void approxEquals(num expected, num actual, [num tolerance = null, String reason = null])
/// Descriptive error message is provided in case of failure.
/// @description Checks that message of thrown ExpectException includes 
///              representation of the expected, actual and tolerance values, as well as the reason.
/// @author varlax
/// @reviewer msyabro

import "../../../Utils/expect.dart";

import "dart:math" as Math;

main() {
  final double MIN_DOUBLE = Math.pow(2.0, -1074);
  final double NEG_MIN_DOUBLE = -1 * MIN_DOUBLE; 
  final double MAX_DOUBLE = (2 - Math.pow(2.0, -52)) * Math.pow(2.0, 1023);
  final double NEG_MAX_DOUBLE = -1 * MAX_DOUBLE; 

  // min double > 0 / 10000
  check(0, MIN_DOUBLE);
  check(0, MIN_DOUBLE, null, "");
  check(0, MIN_DOUBLE, null, "not empty");

  check(0, NEG_MIN_DOUBLE);
  check(0, NEG_MIN_DOUBLE, null, "");
  check(0, NEG_MIN_DOUBLE, null, "not empty");

  check(MAX_DOUBLE, double.infinity);
  check(double.nan, double.negativeInfinity);

  check(20, 2, 1);
  check(MIN_DOUBLE, MAX_DOUBLE, 123, "sddsd");
  check(0, -0.0, double.nan, "");
}

void check(num arg1, num arg2, [num tol = null, String reason = null]) {
  try {
    Expect.approxEquals(arg1, arg2, tol, reason);
    throw new Exception("ExpectException expected");
  } on ExpectException catch(e) {
    if (!e.message.contains(arg1 != null ? arg1.toString() : "null", 0)) throw "no expected value";
    if (!e.message.contains(arg2 != null ? arg2.toString() : "null", 0)) throw "no actual value";
    if (reason != null && !reason.isEmpty && !e.message.contains(reason, 0)) throw "no reason";
    if (arg1 != null && tol == null) {
      tol = (arg1 / Math.pow(10.0, 4.0)).abs();
    }
    if (!e.message.contains(tol.toString(), 0)) throw "no tolerance";
  }
}