extension/test/assert.coffee

   1 ###
   2 # Copyright Simon Lydell 2016.
   3 #
   4 # This file is part of VimFx.
   5 #
   6 # VimFx is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # VimFx is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with VimFx.  If not, see <http://www.gnu.org/licenses/>.
  18 ###
  19
  20 # This file provides a basic assertion library.
  21
  22 createError = (description, message = '') ->
  23   formattedMessage = if message then "\nMessage: #{message}" else ''
  24   error = new Error("Expected #{description}.#{formattedMessage}")
  25   error.stack = error.stack.split('\n')[1..]
  26   return error
  27
  28 format = (value) ->
  29   try
  30     string = JSON.stringify(value)
  31     if string? and not
  32        (string == '{}' and Object::toString.call(value) != '[object Object]')
  33       return string
  34   return String(value)
  35
  36 arrayEqual = (actual, expected, message = '') ->
  37   unless Array.isArray(actual) and Array.isArray(expected)
  38     throw createError(
  39       "two arrays to compare. Got: #{format(actual)} and #{format(expected)}",
  40       message
  41     )
  42   unless actual.length == expected.length and
  43          actual.every((actualItem, index) -> actualItem == expected[index])
  44     throw createError(
  45       "#{format(actual)} to array-equal #{format(expected)}",
  46       message
  47     )
  48
  49 equal = (actual, expected, message = '') ->
  50   return if actual == expected
  51   throw createError("#{format(actual)} to equal #{format(expected)}", message)
  52
  53 notEqual = (actual, expected, message = '') ->
  54   return if actual != expected
  55   throw createError(
  56     "#{format(actual)} NOT to equal #{format(expected)}",
  57     message
  58   )
  59
  60 ok = (actual, message = '') ->
  61   return if actual
  62   throw createError("#{format(actual)} to be truthy", message)
  63
  64 throws = (regex, badValue, fn) ->
  65   try fn() catch error
  66     start = 'VimFx:'
  67     unless error.message.startsWith(start)
  68       throw createError(
  69         "thrown error message #{format(error.message)} to start with
  70          #{format(start)}")
  71     end = ": #{badValue}"
  72     unless error.message.endsWith(end)
  73       throw createError(
  74         "thrown error message #{format(error.message)} to end with
  75          #{format(end)}")
  76     unless regex.test(error.message)
  77       throw createError(
  78         "thrown error message #{format(error.message)} to match the regex
  79          #{format(regex)}")
  80     return
  81   throw createError("function to throw, but it did not: #{format(fn)}")
  82
  83 module.exports = {
  84   arrayEqual
  85   equal
  86   notEqual
  87   ok
  88   throws
  89 }