neovim/test/functional/eval/printf_spec.lua

local helpers = require('test.functional.helpers')(after_each)
local clear = helpers.clear
local eq = helpers.eq
local funcs = helpers.funcs
local exc_exec = helpers.exc_exec

describe('printf()', function()
  before_each(clear)

  it('works with zero and %b', function()
    eq('0', funcs.printf('%lb', 0))
    eq('0', funcs.printf('%llb', 0))
    eq('0', funcs.printf('%zb', 0))
  end)
  it('works with one and %b', function()
    eq('1', funcs.printf('%b', 1))
    eq('1', funcs.printf('%lb', 1))
    eq('1', funcs.printf('%llb', 1))
    eq('1', funcs.printf('%zb', 1))
  end)
  it('works with 0xff and %b', function()
    eq('11111111', funcs.printf('%b', 0xff))
    eq('11111111', funcs.printf('%lb', 0xff))
    eq('11111111', funcs.printf('%llb', 0xff))
    eq('11111111', funcs.printf('%zb', 0xff))
  end)
  it('accepts width modifier with %b', function()
    eq('  1', funcs.printf('%3b', 1))
  end)
  it('accepts prefix modifier with %b', function()
    eq('0b1', funcs.printf('%#b', 1))
  end)
  it('writes capital B with %B', function()
    eq('0B1', funcs.printf('%#B', 1))
  end)
  it('accepts prefix, zero-fill and width modifiers with %b', function()
    eq('0b001', funcs.printf('%#05b', 1))
  end)
  it('accepts prefix and width modifiers with %b', function()
    eq('  0b1', funcs.printf('%#5b', 1))
  end)
  it('does not write prefix for zero with prefix and width modifier used with %b', function()
    eq('    0', funcs.printf('%#5b', 0))
  end)
  it('accepts precision modifier with %b', function()
    eq('00000', funcs.printf('%.5b', 0))
  end)
  it('accepts all modifiers with %b at once', function()
    -- zero-fill modifier is ignored when used with left-align
    -- force-sign and add-blank are ignored
    -- use-grouping-characters modifier is ignored always
    eq('0b00011   ', funcs.printf('% \'+#0-10.5b', 3))
  end)
  it('errors out when %b modifier is used for a list', function()
    eq('Vim(call):E745: Using a List as a Number', exc_exec('call printf("%b", [])'))
  end)
  it('errors out when %b modifier is used for a float', function()
    eq('Vim(call):E805: Using a Float as a Number', exc_exec('call printf("%b", 3.1415926535)'))
  end)
end)