local helpers = require('test.functional.helpers')(after_each)
local clear = helpers.clear
local funcs = helpers.funcs
local meths = helpers.meths
local eq = helpers.eq
local eval = helpers.eval
local command = helpers.command
local exc_exec = helpers.exc_exec
local redir_exec = helpers.redir_exec
local NIL = helpers.NIL
local source = helpers.source

describe('json_decode() function', function()
  local restart = function(...)
    clear(...)
    source([[
      language C
      function Eq(exp, act)
        let act = a:act
        let exp = a:exp
        if type(exp) != type(act)
          return 0
        endif
        if type(exp) == type({})
          if sort(keys(exp)) !=# sort(keys(act))
            return 0
          endif
          if sort(keys(exp)) ==# ['_TYPE', '_VAL']
            let exp_typ = v:msgpack_types[exp._TYPE]
            let act_typ = act._TYPE
            if exp_typ isnot act_typ
              return 0
            endif
            return Eq(exp._VAL, act._VAL)
          else
            return empty(filter(copy(exp), '!Eq(v:val, act[v:key])'))
          endif
        else
          if type(exp) == type([])
            if len(exp) != len(act)
              return 0
            endif
            return empty(filter(copy(exp), '!Eq(v:val, act[v:key])'))
          endif
          return exp ==# act
        endif
        return 1
      endfunction
      function EvalEq(exp, act_expr)
        let act = eval(a:act_expr)
        if Eq(a:exp, act)
          return 1
        else
          return string(act)
        endif
      endfunction
    ]])
  end
  before_each(restart)

  local speq = function(expected, actual_expr)
    eq(1, funcs.EvalEq(expected, actual_expr))
  end

  it('accepts readfile()-style list', function()
    eq({Test=1}, funcs.json_decode({
      '{',
      '\t"Test": 1',
      '}',
    }))
  end)

  it('accepts strings with newlines', function()
    eq({Test=1}, funcs.json_decode([[
      {
        "Test": 1
      }
    ]]))
  end)

  it('parses null, true, false', function()
    eq(NIL, funcs.json_decode('null'))
    eq(true, funcs.json_decode('true'))
    eq(false, funcs.json_decode('false'))
  end)

  it('fails to parse incomplete null, true, false', function()
    eq('Vim(call):E474: Expected null: n',
       exc_exec('call json_decode("n")'))
    eq('Vim(call):E474: Expected null: nu',
       exc_exec('call json_decode("nu")'))
    eq('Vim(call):E474: Expected null: nul',
       exc_exec('call json_decode("nul")'))
    eq('Vim(call):E474: Expected null: nul\n\t',
       exc_exec('call json_decode("nul\\n\\t")'))

    eq('Vim(call):E474: Expected true: t',
       exc_exec('call json_decode("t")'))
    eq('Vim(call):E474: Expected true: tr',
       exc_exec('call json_decode("tr")'))
    eq('Vim(call):E474: Expected true: tru',
       exc_exec('call json_decode("tru")'))
    eq('Vim(call):E474: Expected true: tru\t\n',
       exc_exec('call json_decode("tru\\t\\n")'))

    eq('Vim(call):E474: Expected false: f',
       exc_exec('call json_decode("f")'))
    eq('Vim(call):E474: Expected false: fa',
       exc_exec('call json_decode("fa")'))
    eq('Vim(call):E474: Expected false: fal',
       exc_exec('call json_decode("fal")'))
    eq('Vim(call):E474: Expected false: fal   <',
       exc_exec('call json_decode("   fal   <")'))
    eq('Vim(call):E474: Expected false: fals',
       exc_exec('call json_decode("fals")'))
  end)

  it('parses integer numbers', function()
    eq(100000, funcs.json_decode('100000'))
    eq(-100000, funcs.json_decode('-100000'))
    eq(100000, funcs.json_decode('  100000  '))
    eq(-100000, funcs.json_decode('  -100000  '))
    eq(0, funcs.json_decode('0'))
    eq(0, funcs.json_decode('-0'))
  end)

  it('fails to parse +numbers and .number', function()
    eq('Vim(call):E474: Unidentified byte: +1000',
       exc_exec('call json_decode("+1000")'))
    eq('Vim(call):E474: Unidentified byte: .1000',
       exc_exec('call json_decode(".1000")'))
  end)

  it('fails to parse numbers with leading zeroes', function()
    eq('Vim(call):E474: Leading zeroes are not allowed: 00.1',
       exc_exec('call json_decode("00.1")'))
    eq('Vim(call):E474: Leading zeroes are not allowed: 01',
       exc_exec('call json_decode("01")'))
    eq('Vim(call):E474: Leading zeroes are not allowed: -01',
       exc_exec('call json_decode("-01")'))
    eq('Vim(call):E474: Leading zeroes are not allowed: -001.0',
       exc_exec('call json_decode("-001.0")'))
  end)

  it('fails to parse incomplete numbers', function()
    eq('Vim(call):E474: Missing number after minus sign: -.1',
       exc_exec('call json_decode("-.1")'))
    eq('Vim(call):E474: Missing number after minus sign: -',
       exc_exec('call json_decode("-")'))
    eq('Vim(call):E474: Missing number after decimal dot: -1.',
       exc_exec('call json_decode("-1.")'))
    eq('Vim(call):E474: Missing number after decimal dot: 0.',
       exc_exec('call json_decode("0.")'))
    eq('Vim(call):E474: Missing exponent: 0.0e',
       exc_exec('call json_decode("0.0e")'))
    eq('Vim(call):E474: Missing exponent: 0.0e+',
       exc_exec('call json_decode("0.0e+")'))
    eq('Vim(call):E474: Missing exponent: 0.0e-',
       exc_exec('call json_decode("0.0e-")'))
    eq('Vim(call):E474: Missing exponent: 0.0e-',
       exc_exec('call json_decode("0.0e-")'))
    eq('Vim(call):E474: Missing number after decimal dot: 1.e5',
       exc_exec('call json_decode("1.e5")'))
    eq('Vim(call):E474: Missing number after decimal dot: 1.e+5',
       exc_exec('call json_decode("1.e+5")'))
    eq('Vim(call):E474: Missing number after decimal dot: 1.e+',
       exc_exec('call json_decode("1.e+")'))
  end)

  it('parses floating-point numbers', function()
    eq('100000.0', eval('string(json_decode("100000.0"))'))
    eq(100000.5, funcs.json_decode('100000.5'))
    eq(-100000.5, funcs.json_decode('-100000.5'))
    eq(-100000.5e50, funcs.json_decode('-100000.5e50'))
    eq(100000.5e50, funcs.json_decode('100000.5e50'))
    eq(100000.5e50, funcs.json_decode('100000.5e+50'))
    eq(-100000.5e-50, funcs.json_decode('-100000.5e-50'))
    eq(100000.5e-50, funcs.json_decode('100000.5e-50'))
    eq(100000e-50, funcs.json_decode('100000e-50'))
    eq(0.5, funcs.json_decode('0.5'))
    eq(0.005, funcs.json_decode('0.005'))
    eq(0.005, funcs.json_decode('0.00500'))
    eq(0.5, funcs.json_decode('0.00500e+002'))
    eq(0.00005, funcs.json_decode('0.00500e-002'))

    eq(-0.0, funcs.json_decode('-0.0'))
    eq(-0.0, funcs.json_decode('-0.0e0'))
    eq(-0.0, funcs.json_decode('-0.0e+0'))
    eq(-0.0, funcs.json_decode('-0.0e-0'))
    eq(-0.0, funcs.json_decode('-0e-0'))
    eq(-0.0, funcs.json_decode('-0e-2'))
    eq(-0.0, funcs.json_decode('-0e+2'))

    eq(0.0, funcs.json_decode('0.0'))
    eq(0.0, funcs.json_decode('0.0e0'))
    eq(0.0, funcs.json_decode('0.0e+0'))
    eq(0.0, funcs.json_decode('0.0e-0'))
    eq(0.0, funcs.json_decode('0e-0'))
    eq(0.0, funcs.json_decode('0e-2'))
    eq(0.0, funcs.json_decode('0e+2'))
  end)

  it('fails to parse numbers with spaces inside', function()
    eq('Vim(call):E474: Missing number after minus sign: - 1000',
       exc_exec('call json_decode("- 1000")'))
    eq('Vim(call):E474: Missing number after decimal dot: 0. ',
       exc_exec('call json_decode("0. ")'))
    eq('Vim(call):E474: Missing number after decimal dot: 0. 0',
       exc_exec('call json_decode("0. 0")'))
    eq('Vim(call):E474: Missing exponent: 0.0e 1',
       exc_exec('call json_decode("0.0e 1")'))
    eq('Vim(call):E474: Missing exponent: 0.0e+ 1',
       exc_exec('call json_decode("0.0e+ 1")'))
    eq('Vim(call):E474: Missing exponent: 0.0e- 1',
       exc_exec('call json_decode("0.0e- 1")'))
  end)

  it('fails to parse "," and ":"', function()
    eq('Vim(call):E474: Comma not inside container: ,  ',
       exc_exec('call json_decode("  ,  ")'))
    eq('Vim(call):E474: Colon not inside container: :  ',
       exc_exec('call json_decode("  :  ")'))
  end)

  it('parses empty containers', function()
    eq({}, funcs.json_decode('[]'))
    eq('[]', eval('string(json_decode("[]"))'))
  end)

  it('fails to parse "[" and "{"', function()
    eq('Vim(call):E474: Unexpected end of input: {',
       exc_exec('call json_decode("{")'))
    eq('Vim(call):E474: Unexpected end of input: [',
       exc_exec('call json_decode("[")'))
  end)

  it('fails to parse "}" and "]"', function()
    eq('Vim(call):E474: No container to close: ]',
       exc_exec('call json_decode("]")'))
    eq('Vim(call):E474: No container to close: }',
       exc_exec('call json_decode("}")'))
  end)

  it('fails to parse containers which are closed by different brackets',
  function()
    eq('Vim(call):E474: Closing dictionary with square bracket: ]',
       exc_exec('call json_decode("{]")'))
    eq('Vim(call):E474: Closing list with curly bracket: }',
       exc_exec('call json_decode("[}")'))
  end)

  it('fails to parse concat inside container', function()
    eq('Vim(call):E474: Expected comma before list item: []]',
       exc_exec('call json_decode("[[][]]")'))
    eq('Vim(call):E474: Expected comma before list item: {}]',
       exc_exec('call json_decode("[{}{}]")'))
    eq('Vim(call):E474: Expected comma before list item: ]',
       exc_exec('call json_decode("[1 2]")'))
    eq('Vim(call):E474: Expected comma before dictionary key: ": 4}',
       exc_exec('call json_decode("{\\"1\\": 2 \\"3\\": 4}")'))
    eq('Vim(call):E474: Expected colon before dictionary value: , "3" 4}',
       exc_exec('call json_decode("{\\"1\\" 2, \\"3\\" 4}")'))
  end)

  it('fails to parse containers with leading comma or colon', function()
    eq('Vim(call):E474: Leading comma: ,}',
       exc_exec('call json_decode("{,}")'))
    eq('Vim(call):E474: Leading comma: ,]',
       exc_exec('call json_decode("[,]")'))
    eq('Vim(call):E474: Using colon not in dictionary: :]',
       exc_exec('call json_decode("[:]")'))
    eq('Vim(call):E474: Unexpected colon: :}',
       exc_exec('call json_decode("{:}")'))
  end)

  it('fails to parse containers with trailing comma', function()
    eq('Vim(call):E474: Trailing comma: ]',
       exc_exec('call json_decode("[1,]")'))
    eq('Vim(call):E474: Trailing comma: }',
       exc_exec('call json_decode("{\\"1\\": 2,}")'))
  end)

  it('fails to parse dictionaries with missing value', function()
    eq('Vim(call):E474: Expected value after colon: }',
       exc_exec('call json_decode("{\\"1\\":}")'))
    eq('Vim(call):E474: Expected value: }',
       exc_exec('call json_decode("{\\"1\\"}")'))
  end)

  it('fails to parse containers with two commas or colons', function()
    eq('Vim(call):E474: Duplicate comma: , "2": 2}',
       exc_exec('call json_decode("{\\"1\\": 1,, \\"2\\": 2}")'))
    eq('Vim(call):E474: Duplicate comma: , "2", 2]',
       exc_exec('call json_decode("[\\"1\\", 1,, \\"2\\", 2]")'))
    eq('Vim(call):E474: Duplicate colon: : 2}',
       exc_exec('call json_decode("{\\"1\\": 1, \\"2\\":: 2}")'))
    eq('Vim(call):E474: Comma after colon: , 2}',
       exc_exec('call json_decode("{\\"1\\": 1, \\"2\\":, 2}")'))
    eq('Vim(call):E474: Unexpected colon: : "2": 2}',
       exc_exec('call json_decode("{\\"1\\": 1,: \\"2\\": 2}")'))
    eq('Vim(call):E474: Unexpected colon: :, "2": 2}',
       exc_exec('call json_decode("{\\"1\\": 1:, \\"2\\": 2}")'))
  end)

  it('fails to parse concat of two values', function()
    eq('Vim(call):E474: Trailing characters: []',
       exc_exec('call json_decode("{}[]")'))
  end)

  it('parses containers', function()
    eq({1}, funcs.json_decode('[1]'))
    eq({NIL, 1}, funcs.json_decode('[null, 1]'))
    eq({['1']=2}, funcs.json_decode('{"1": 2}'))
    eq({['1']=2, ['3']={{['4']={['5']={{}, 1}}}}},
       funcs.json_decode('{"1": 2, "3": [{"4": {"5": [[], 1]}}]}'))
  end)

  it('fails to parse incomplete strings', function()
    eq('Vim(call):E474: Expected string end: \t"',
       exc_exec('call json_decode("\\t\\"")'))
    eq('Vim(call):E474: Expected string end: \t"abc',
       exc_exec('call json_decode("\\t\\"abc")'))
    eq('Vim(call):E474: Unfinished escape sequence: \t"abc\\',
       exc_exec('call json_decode("\\t\\"abc\\\\")'))
    eq('Vim(call):E474: Unfinished unicode escape sequence: \t"abc\\u',
       exc_exec('call json_decode("\\t\\"abc\\\\u")'))
    eq('Vim(call):E474: Unfinished unicode escape sequence: \t"abc\\u0',
       exc_exec('call json_decode("\\t\\"abc\\\\u0")'))
    eq('Vim(call):E474: Unfinished unicode escape sequence: \t"abc\\u00',
       exc_exec('call json_decode("\\t\\"abc\\\\u00")'))
    eq('Vim(call):E474: Unfinished unicode escape sequence: \t"abc\\u000',
       exc_exec('call json_decode("\\t\\"abc\\\\u000")'))
    eq('Vim(call):E474: Expected four hex digits after \\u: \\u"    ',
       exc_exec('call json_decode("\\t\\"abc\\\\u\\"    ")'))
    eq('Vim(call):E474: Expected four hex digits after \\u: \\u0"    ',
       exc_exec('call json_decode("\\t\\"abc\\\\u0\\"    ")'))
    eq('Vim(call):E474: Expected four hex digits after \\u: \\u00"    ',
       exc_exec('call json_decode("\\t\\"abc\\\\u00\\"    ")'))
    eq('Vim(call):E474: Expected four hex digits after \\u: \\u000"    ',
       exc_exec('call json_decode("\\t\\"abc\\\\u000\\"    ")'))
    eq('Vim(call):E474: Expected string end: \t"abc\\u0000',
       exc_exec('call json_decode("\\t\\"abc\\\\u0000")'))
  end)

  it('fails to parse unknown escape sequnces', function()
    eq('Vim(call):E474: Unknown escape sequence: \\a"',
       exc_exec('call json_decode("\\t\\"\\\\a\\"")'))
  end)

  it('parses strings properly', function()
    eq('\n', funcs.json_decode('"\\n"'))
    eq('', funcs.json_decode('""'))
    eq('\\/"\t\b\n\r\f', funcs.json_decode([["\\\/\"\t\b\n\r\f"]]))
    eq('/a', funcs.json_decode([["\/a"]]))
    -- Unicode characters: 2-byte, 3-byte, 4-byte
    eq({
      '«',
      'ફ',
      '\240\144\128\128',
    }, funcs.json_decode({
      '[',
      '"«",',
      '"ફ",',
      '"\240\144\128\128"',
      ']',
    }))
  end)

  it('fails on strings with invalid bytes', function()
    eq('Vim(call):E474: Only UTF-8 strings allowed: \255"',
       exc_exec('call json_decode("\\t\\"\\xFF\\"")'))
    eq('Vim(call):E474: ASCII control characters cannot be present inside string: ',
       exc_exec('call json_decode(["\\"\\n\\""])'))
    -- 0xC2 starts 2-byte unicode character
    eq('Vim(call):E474: Only UTF-8 strings allowed: \194"',
       exc_exec('call json_decode("\\t\\"\\xC2\\"")'))
    -- 0xE0 0xAA starts 3-byte unicode character
    eq('Vim(call):E474: Only UTF-8 strings allowed: \224"',
       exc_exec('call json_decode("\\t\\"\\xE0\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \224\170"',
       exc_exec('call json_decode("\\t\\"\\xE0\\xAA\\"")'))
    -- 0xF0 0x90 0x80 starts 4-byte unicode character
    eq('Vim(call):E474: Only UTF-8 strings allowed: \240"',
       exc_exec('call json_decode("\\t\\"\\xF0\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \240\144"',
       exc_exec('call json_decode("\\t\\"\\xF0\\x90\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \240\144\128"',
       exc_exec('call json_decode("\\t\\"\\xF0\\x90\\x80\\"")'))
    -- 0xF9 0x80 0x80 0x80 starts 5-byte unicode character
    eq('Vim(call):E474: Only UTF-8 strings allowed: \249"',
       exc_exec('call json_decode("\\t\\"\\xF9\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \249\128"',
       exc_exec('call json_decode("\\t\\"\\xF9\\x80\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \249\128\128"',
       exc_exec('call json_decode("\\t\\"\\xF9\\x80\\x80\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \249\128\128\128"',
       exc_exec('call json_decode("\\t\\"\\xF9\\x80\\x80\\x80\\"")'))
    -- 0xFC 0x90 0x80 0x80 0x80 starts 6-byte unicode character
    eq('Vim(call):E474: Only UTF-8 strings allowed: \252"',
       exc_exec('call json_decode("\\t\\"\\xFC\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \252\144"',
       exc_exec('call json_decode("\\t\\"\\xFC\\x90\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \252\144\128"',
       exc_exec('call json_decode("\\t\\"\\xFC\\x90\\x80\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \252\144\128\128"',
       exc_exec('call json_decode("\\t\\"\\xFC\\x90\\x80\\x80\\"")'))
    eq('Vim(call):E474: Only UTF-8 strings allowed: \252\144\128\128\128"',
       exc_exec('call json_decode("\\t\\"\\xFC\\x90\\x80\\x80\\x80\\"")'))
    -- Specification does not allow unquoted characters above 0x10FFFF
    eq('Vim(call):E474: Only UTF-8 code points up to U+10FFFF are allowed to appear unescaped: \249\128\128\128\128"',
       exc_exec('call json_decode("\\t\\"\\xF9\\x80\\x80\\x80\\x80\\"")'))
    eq('Vim(call):E474: Only UTF-8 code points up to U+10FFFF are allowed to appear unescaped: \252\144\128\128\128\128"',
       exc_exec('call json_decode("\\t\\"\\xFC\\x90\\x80\\x80\\x80\\x80\\"")'))
    -- '"\249\128\128\128\128"',
    -- '"\252\144\128\128\128\128"',
  end)

  it('parses surrogate pairs properly', function()
    eq('\240\144\128\128', funcs.json_decode('"\\uD800\\uDC00"'))
    eq('\237\160\128a\237\176\128', funcs.json_decode('"\\uD800a\\uDC00"'))
    eq('\237\160\128\t\237\176\128', funcs.json_decode('"\\uD800\\t\\uDC00"'))

    eq('\237\160\128', funcs.json_decode('"\\uD800"'))
    eq('\237\160\128a', funcs.json_decode('"\\uD800a"'))
    eq('\237\160\128\t', funcs.json_decode('"\\uD800\\t"'))

    eq('\237\176\128', funcs.json_decode('"\\uDC00"'))
    eq('\237\176\128a', funcs.json_decode('"\\uDC00a"'))
    eq('\237\176\128\t', funcs.json_decode('"\\uDC00\\t"'))

    eq('\237\176\128', funcs.json_decode('"\\uDC00"'))
    eq('a\237\176\128', funcs.json_decode('"a\\uDC00"'))
    eq('\t\237\176\128', funcs.json_decode('"\\t\\uDC00"'))

    eq('\237\160\128¬', funcs.json_decode('"\\uD800\\u00AC"'))

    eq('\237\160\128\237\160\128', funcs.json_decode('"\\uD800\\uD800"'))
  end)

  local sp_decode_eq = function(expected, json)
    meths.set_var('__json', json)
    speq(expected, 'json_decode(g:__json)')
    command('unlet! g:__json')
  end

  it('parses strings with NUL properly', function()
    sp_decode_eq({_TYPE='string', _VAL={'\n'}}, '"\\u0000"')
    sp_decode_eq({_TYPE='string', _VAL={'\n', '\n'}}, '"\\u0000\\n\\u0000"')
    sp_decode_eq({_TYPE='string', _VAL={'\n«\n'}}, '"\\u0000\\u00AB\\u0000"')
  end)

  it('parses dictionaries with duplicate keys to special maps', function()
    sp_decode_eq({_TYPE='map', _VAL={{'a', 1}, {'a', 2}}},
                 '{"a": 1, "a": 2}')
    sp_decode_eq({_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'a', 2}}},
                 '{"b": 3, "a": 1, "a": 2}')
    sp_decode_eq({_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'a', 2}}},
                 '{"b": 3, "a": 1, "c": 4, "a": 2}')
    sp_decode_eq({_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'a', 2}, {'c', 4}}},
                 '{"b": 3, "a": 1, "c": 4, "a": 2, "c": 4}')
    sp_decode_eq({{_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'a', 2}, {'c', 4}}}},
                 '[{"b": 3, "a": 1, "c": 4, "a": 2, "c": 4}]')
    sp_decode_eq({{d={_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'a', 2}, {'c', 4}}}}},
                 '[{"d": {"b": 3, "a": 1, "c": 4, "a": 2, "c": 4}}]')
    sp_decode_eq({1, {d={_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'a', 2}, {'c', 4}}}}},
                 '[1, {"d": {"b": 3, "a": 1, "c": 4, "a": 2, "c": 4}}]')
    sp_decode_eq({1, {a={}, d={_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'a', 2}, {'c', 4}}}}},
                 '[1, {"a": [], "d": {"b": 3, "a": 1, "c": 4, "a": 2, "c": 4}}]')
  end)

  it('parses dictionaries with empty keys to special maps', function()
    sp_decode_eq({_TYPE='map', _VAL={{'', 4}}},
                 '{"": 4}')
    sp_decode_eq({_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'d', 2}, {'', 4}}},
                 '{"b": 3, "a": 1, "c": 4, "d": 2, "": 4}')
    sp_decode_eq({_TYPE='map', _VAL={{'', 3}, {'a', 1}, {'c', 4}, {'d', 2}, {'', 4}}},
                 '{"": 3, "a": 1, "c": 4, "d": 2, "": 4}')
    sp_decode_eq({{_TYPE='map', _VAL={{'', 3}, {'a', 1}, {'c', 4}, {'d', 2}, {'', 4}}}},
                 '[{"": 3, "a": 1, "c": 4, "d": 2, "": 4}]')
  end)

  it('parses dictionaries with keys with NUL bytes to special maps', function()
    sp_decode_eq({_TYPE='map', _VAL={{{_TYPE='string', _VAL={'a\n', 'b'}}, 4}}},
                 '{"a\\u0000\\nb": 4}')
    sp_decode_eq({_TYPE='map', _VAL={{{_TYPE='string', _VAL={'a\n', 'b', ''}}, 4}}},
                 '{"a\\u0000\\nb\\n": 4}')
    sp_decode_eq({_TYPE='map', _VAL={{'b', 3}, {'a', 1}, {'c', 4}, {'d', 2}, {{_TYPE='string', _VAL={'\n'}}, 4}}},
                 '{"b": 3, "a": 1, "c": 4, "d": 2, "\\u0000": 4}')
  end)

  it('parses U+00C3 correctly', function()
    eq('\195\131', funcs.json_decode('"\195\131"'))
  end)

  it('fails to parse empty string', function()
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode("")'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode([])'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode([""])'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode(" ")'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode("\\t")'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode("\\n")'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode(" \\t\\n \\n\\t\\t \\n\\t\\n \\n \\t\\n\\t ")'))
  end)

  it('accepts all spaces in every position where space may be put', function()
    local s = ' \t\n\r \t\r\n \n\t\r \n\r\t \r\t\n \r\n\t\t \n\r\t \r\n\t\n \r\t\n\r \t\r \n\t\r\n \n \t\r\n \r\t\n\t \r\n\t\r \n\r \t\n\r\t \r \t\n\r \n\t\r\t \n\r\t\n \r\n \t\r\n\t'
    local str = ('%s{%s"key"%s:%s[%s"val"%s,%s"val2"%s]%s,%s"key2"%s:%s1%s}%s'):gsub('%%s', s)
    eq({key={'val', 'val2'}, key2=1}, funcs.json_decode(str))
  end)

  it('does not overflow when writing error message about decoding ["", ""]',
  function()
    eq('\nE474: Attempt to decode a blank string'
       .. '\nE474: Failed to parse \n',
       redir_exec('call json_decode(["", ""])'))
  end)
end)

describe('json_encode() function', function()
  before_each(function()
    clear()
    command('language C')
  end)

  it('dumps strings', function()
    eq('"Test"', funcs.json_encode('Test'))
    eq('""', funcs.json_encode(''))
    eq('"\\t"', funcs.json_encode('\t'))
    eq('"\\n"', funcs.json_encode('\n'))
    eq('"\\u001B"', funcs.json_encode('\27'))
    eq('"þÿþ"', funcs.json_encode('þÿþ'))
  end)

  it('dumps numbers', function()
    eq('0', funcs.json_encode(0))
    eq('10', funcs.json_encode(10))
    eq('-10', funcs.json_encode(-10))
  end)

  it('dumps floats', function()
    eq('0.0', eval('json_encode(0.0)'))
    eq('10.5', funcs.json_encode(10.5))
    eq('-10.5', funcs.json_encode(-10.5))
    eq('-1.0e-5', funcs.json_encode(-1e-5))
    eq('1.0e50', eval('json_encode(1.0e50)'))
  end)

  it('fails to dump NaN and infinite values', function()
    eq('Vim(call):E474: Unable to represent NaN value in JSON',
       exc_exec('call json_encode(str2float("nan"))'))
    eq('Vim(call):E474: Unable to represent infinity in JSON',
       exc_exec('call json_encode(str2float("inf"))'))
    eq('Vim(call):E474: Unable to represent infinity in JSON',
       exc_exec('call json_encode(-str2float("inf"))'))
  end)

  it('dumps lists', function()
    eq('[]', funcs.json_encode({}))
    eq('[[]]', funcs.json_encode({{}}))
    eq('[[], []]', funcs.json_encode({{}, {}}))
  end)

  it('dumps dictionaries', function()
    eq('{}', eval('json_encode({})'))
    eq('{"d": []}', funcs.json_encode({d={}}))
    eq('{"d": [], "e": []}', funcs.json_encode({d={}, e={}}))
  end)

  it('cannot dump generic mapping with generic mapping keys and values',
  function()
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": []}')
    command('let todumpv1 = {"_TYPE": v:msgpack_types.map, "_VAL": []}')
    command('let todumpv2 = {"_TYPE": v:msgpack_types.map, "_VAL": []}')
    command('call add(todump._VAL, [todumpv1, todumpv2])')
    eq('Vim(call):E474: Invalid key in special dictionary', exc_exec('call json_encode(todump)'))
  end)

  it('cannot dump generic mapping with ext key', function()
    command('let todump = {"_TYPE": v:msgpack_types.ext, "_VAL": [5, ["",""]]}')
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [[todump, 1]]}')
    eq('Vim(call):E474: Invalid key in special dictionary', exc_exec('call json_encode(todump)'))
  end)

  it('cannot dump generic mapping with array key', function()
    command('let todump = {"_TYPE": v:msgpack_types.array, "_VAL": [5, [""]]}')
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [[todump, 1]]}')
    eq('Vim(call):E474: Invalid key in special dictionary', exc_exec('call json_encode(todump)'))
  end)

  it('cannot dump generic mapping with UINT64_MAX key', function()
    command('let todump = {"_TYPE": v:msgpack_types.integer}')
    command('let todump._VAL = [1, 3, 0x7FFFFFFF, 0x7FFFFFFF]')
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [[todump, 1]]}')
    eq('Vim(call):E474: Invalid key in special dictionary', exc_exec('call json_encode(todump)'))
  end)

  it('cannot dump generic mapping with floating-point key', function()
    command('let todump = {"_TYPE": v:msgpack_types.float, "_VAL": 0.125}')
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [[todump, 1]]}')
    eq('Vim(call):E474: Invalid key in special dictionary', exc_exec('call json_encode(todump)'))
  end)

  it('can dump generic mapping with STR special key and NUL', function()
    command('let todump = {"_TYPE": v:msgpack_types.string, "_VAL": ["\\n"]}')
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [[todump, 1]]}')
    eq('{"\\u0000": 1}', eval('json_encode(todump)'))
  end)

  it('can dump generic mapping with BIN special key and NUL', function()
    command('let todump = {"_TYPE": v:msgpack_types.binary, "_VAL": ["\\n"]}')
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [[todump, 1]]}')
    eq('{"\\u0000": 1}', eval('json_encode(todump)'))
  end)

  it('can dump STR special mapping with NUL and NL', function()
    command('let todump = {"_TYPE": v:msgpack_types.string, "_VAL": ["\\n", ""]}')
    eq('"\\u0000\\n"', eval('json_encode(todump)'))
  end)

  it('can dump BIN special mapping with NUL and NL', function()
    command('let todump = {"_TYPE": v:msgpack_types.binary, "_VAL": ["\\n", ""]}')
    eq('"\\u0000\\n"', eval('json_encode(todump)'))
  end)

  it('cannot dump special ext mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.ext, "_VAL": [5, ["",""]]}')
    eq('Vim(call):E474: Unable to convert EXT string to JSON', exc_exec('call json_encode(todump)'))
  end)

  it('can dump special array mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.array, "_VAL": [5, [""]]}')
    eq('[5, [""]]', eval('json_encode(todump)'))
  end)

  it('can dump special UINT64_MAX mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.integer}')
    command('let todump._VAL = [1, 3, 0x7FFFFFFF, 0x7FFFFFFF]')
    eq('18446744073709551615', eval('json_encode(todump)'))
  end)

  it('can dump special INT64_MIN mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.integer}')
    command('let todump._VAL = [-1, 2, 0, 0]')
    eq('-9223372036854775808', eval('json_encode(todump)'))
  end)

  it('can dump special BOOLEAN true mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.boolean, "_VAL": 1}')
    eq('true', eval('json_encode(todump)'))
  end)

  it('can dump special BOOLEAN false mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.boolean, "_VAL": 0}')
    eq('false', eval('json_encode(todump)'))
  end)

  it('can dump special NIL mapping', function()
    command('let todump = {"_TYPE": v:msgpack_types.nil, "_VAL": 0}')
    eq('null', eval('json_encode(todump)'))
  end)

  it('fails to dump a function reference', function()
    eq('Vim(call):E474: Error while dumping encode_tv2json() argument, itself: attempt to dump function reference',
       exc_exec('call json_encode(function("tr"))'))
  end)

  it('fails to dump a partial', function()
    command('function T() dict\nendfunction')
    eq('Vim(call):E474: Error while dumping encode_tv2json() argument, itself: attempt to dump function reference',
       exc_exec('call json_encode(function("T", [1, 2], {}))'))
  end)

  it('fails to dump a function reference in a list', function()
    eq('Vim(call):E474: Error while dumping encode_tv2json() argument, index 0: attempt to dump function reference',
       exc_exec('call json_encode([function("tr")])'))
  end)

  it('fails to dump a recursive list', function()
    command('let todump = [[[]]]')
    command('call add(todump[0][0], todump)')
    eq('Vim(call):E724: unable to correctly dump variable with self-referencing container',
       exc_exec('call json_encode(todump)'))
  end)

  it('fails to dump a recursive dict', function()
    command('let todump = {"d": {"d": {}}}')
    command('call extend(todump.d.d, {"d": todump})')
    eq('Vim(call):E724: unable to correctly dump variable with self-referencing container',
       exc_exec('call json_encode([todump])'))
  end)

  it('can dump dict with two same dicts inside', function()
    command('let inter = {}')
    command('let todump = {"a": inter, "b": inter}')
    eq('{"a": {}, "b": {}}', eval('json_encode(todump)'))
  end)

  it('can dump list with two same lists inside', function()
    command('let inter = []')
    command('let todump = [inter, inter]')
    eq('[[], []]', eval('json_encode(todump)'))
  end)

  it('fails to dump a recursive list in a special dict', function()
    command('let todump = {"_TYPE": v:msgpack_types.array, "_VAL": []}')
    command('call add(todump._VAL, todump)')
    eq('Vim(call):E724: unable to correctly dump variable with self-referencing container',
       exc_exec('call json_encode(todump)'))
  end)

  it('fails to dump a recursive (val) map in a special dict', function()
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": []}')
    command('call add(todump._VAL, ["", todump])')
    eq('Vim(call):E724: unable to correctly dump variable with self-referencing container',
       exc_exec('call json_encode([todump])'))
  end)

  it('fails to dump a recursive (val) map in a special dict, _VAL reference', function()
    command('let todump = {"_TYPE": v:msgpack_types.map, "_VAL": [["", []]]}')
    command('call add(todump._VAL[0][1], todump._VAL)')
    eq('Vim(call):E724: unable to correctly dump variable with self-referencing container',
       exc_exec('call json_encode(todump)'))
  end)

  it('fails to dump a recursive (val) special list in a special dict',
  function()
    command('let todump = {"_TYPE": v:msgpack_types.array, "_VAL": []}')
    command('call add(todump._VAL, ["", todump._VAL])')
    eq('Vim(call):E724: unable to correctly dump variable with self-referencing container',
       exc_exec('call json_encode(todump)'))
  end)

  it('fails when called with no arguments', function()
    eq('Vim(call):E119: Not enough arguments for function: json_encode',
       exc_exec('call json_encode()'))
  end)

  it('fails when called with two arguments', function()
    eq('Vim(call):E118: Too many arguments for function: json_encode',
       exc_exec('call json_encode(["", ""], 1)'))
  end)

  it('ignores improper values in &isprint', function()
    meths.set_option('isprint', '1')
    eq(1, eval('"\1" =~# "\\\\p"'))
    eq('"\\u0001"', funcs.json_encode('\1'))
  end)

  it('fails when using surrogate character in a UTF-8 string', function()
    eq('Vim(call):E474: UTF-8 string contains code point which belongs to a surrogate pair: \237\160\128',
       exc_exec('call json_encode("\237\160\128")'))
    eq('Vim(call):E474: UTF-8 string contains code point which belongs to a surrogate pair: \237\175\191',
       exc_exec('call json_encode("\237\175\191")'))
  end)

  it('dumps control characters as expected', function()
    eq([["\u0000\u0001\u0002\u0003\u0004\u0005\u0006\u0007\b\t\n\u000B\f\r\u000E\u000F\u0010\u0011\u0012\u0013"]],
       eval('json_encode({"_TYPE": v:msgpack_types.string, "_VAL": ["\n\1\2\3\4\5\6\7\8\9", "\11\12\13\14\15\16\17\18\19"]})'))
  end)

  it('can dump NULL string', function()
    eq('""', eval('json_encode($XXX_UNEXISTENT_VAR_XXX)'))
  end)

  it('can dump NULL list', function()
    eq('[]', eval('json_encode(v:_null_list)'))
  end)

  it('can dump NULL dictionary', function()
    eq('{}', eval('json_encode(v:_null_dict)'))
  end)

  it('fails to parse NULL strings and lists', function()
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode($XXX_UNEXISTENT_VAR_XXX)'))
    eq('Vim(call):E474: Attempt to decode a blank string',
       exc_exec('call json_decode(v:_null_list)'))
  end)
end)
