jasmine/spec/core/matchers/toThrowMatchingSpec.js

describe("toThrowMatching", function() {
  it("throws an error when the actual is not a function", function() {
    var matcher = jasmineUnderTest.matchers.toThrowMatching();

    expect(function() {
      matcher.compare({}, function() { return true; });
    }).toThrowError(/Actual is not a Function/);
  });

  it("throws an error when the expected is not a function", function() {
    var matcher = jasmineUnderTest.matchers.toThrowMatching(),
      fn = function() {
        throw new Error("foo");
      };

    expect(function() {
      matcher.compare(fn, 1);
    }).toThrowError(/Predicate is not a Function/);
  });

  it("fails if actual does not throw at all", function() {
    var matcher = jasmineUnderTest.matchers.toThrowMatching(),
      fn = function() {
        return true;
      },
      result;

    result = matcher.compare(fn, function() { return true; });

    expect(result.pass).toBe(false);
    expect(result.message).toEqual("Expected function to throw an exception.");
  });

  it("fails with the correct message if thrown is a falsy value", function() {
    var matcher = jasmineUnderTest.matchers.toThrowMatching(),
      fn = function() {
        throw undefined;
      },
      result;

    result = matcher.compare(fn, function() { return false; });
    expect(result.pass).toBe(false);
    expect(result.message()).toEqual("Expected function to throw an exception matching a predicate, but it threw undefined.");
  });

  it("passes if the argument is a function that returns true when called with the error", function() {
    var matcher = jasmineUnderTest.matchers.toThrowMatching(),
    predicate = function(e) { return e.message === "nope" },
      fn = function() {
        throw new TypeError("nope");
      },
      result;

    result = matcher.compare(fn, predicate);

    expect(result.pass).toBe(true);
    expect(result.message).toEqual("Expected function not to throw an exception matching a predicate.");
  });

  it("fails if the argument is a function that returns false when called with the error", function() {
    var matcher = jasmineUnderTest.matchers.toThrowMatching(),
    predicate = function(e) { return e.message === "oh no" },
      fn = function() {
        throw new TypeError("nope");
      },
      result;

    result = matcher.compare(fn, predicate);

    expect(result.pass).toBe(false);
    expect(result.message()).toEqual("Expected function to throw an exception matching a predicate, but it threw TypeError with message 'nope'.");
  });
});