util.promise: Remove some redundant checks, add tests confirming redundancy
This lines don't appear to do anything useful, and all tests pass when they
are removed. Discovered via mutation testing.
I added extra tests to exercise this code, because I wasn't certain that there
were no side-effects caused by removal. Everything appears to be fine, thanks
to the "pending" check at the start of promise_settle().
local s_char = string.char;
local s_format = string.format;
local s_gsub = string.gsub;
local s_lower = string.lower;
local char_to_hex = {};
local hex_to_char = {};
do
local char, hex;
for i = 0,255 do
char, hex = s_char(i), s_format("%02x", i);
char_to_hex[char] = hex;
hex_to_char[hex] = char;
end
end
local function to(s)
return (s_gsub(s, ".", char_to_hex));
end
local function from(s)
return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
end
return {
encode = to, decode = from;
-- COMPAT w/pre-0.12:
to = to, from = from;
};