must/test/must/length_test.js

Testing and assertion library with friendly BDD syntax — awesome.must.be.true(). Many expressive matchers and is test runner and framework agnostic. Follows RFC 2119 with its use of MUST. Good and well tested stuff.

var Must = require("../..")
var assert = require("./assert")

describe("Must.prototype.length", function() {
  describe("given String", function() {
    it("must pass if length equal", function() {
      assert.pass(function() { Must("hello").have.length(5) })
    })

    it("must fail if length not equal", function() {
      assert.fail(function() { Must("hello").have.length(42) })
    })
  })

  describe("given Array", function() {
    it("must pass if length equal", function() {
      assert.pass(function() { Must([1, 2, 3, 4]).have.length(4) })
    })

    it("must fail if length not equal", function() {
      assert.fail(function() { Must([1, 2, 3, 4]).have.length(42) })
    })
  })

  require("./_assertion_error_test")(function() {
    Must("hello").have.length(42)
  }, {
    actual: "hello",
    expected: 42,
    message: "\"hello\" must have length of 42"
  })

  describe(".not", function() {
    it("must invert the assertion", function() {
      assert.fail(function() { Must("hello").not.have.length(5) })
    })
  })
})