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denoland-deno/tests/testdata/commonjs/node_modules/left-pad/index.js
Matt Mastracci f5e46c9bf2
chore: move cli/tests/ -> tests/ (#22369)
This looks like a massive PR, but it's only a move from cli/tests ->
tests, and updates of relative paths for files.

This is the first step towards aggregate all of the integration test
files under tests/, which will lead to a set of integration tests that
can run without the CLI binary being built.

While we could leave these tests under `cli`, it would require us to
keep a more complex directory structure for the various test runners. In
addition, we have a lot of complexity to ignore various test files in
the `cli` project itself (cargo publish exclusion rules, autotests =
false, etc).

And finally, the `tests/` folder will eventually house the `test_ffi`,
`test_napi` and other testing code, reducing the size of the root repo
directory.

For easier review, the extremely large and noisy "move" is in the first
commit (with no changes -- just a move), while the remainder of the
changes to actual files is in the second commit.
2024-02-10 20:22:13 +00:00

54 lines
1.5 KiB
JavaScript

// deno-lint-ignore-file
/* This program is free software. It comes without any warranty, to
* the extent permitted by applicable law. You can redistribute it
* and/or modify it under the terms of the Do What The Fuck You Want
* To Public License, Version 2, as published by Sam Hocevar. See
* http://www.wtfpl.net/ for more details. */
"use strict";
module.exports = leftPad;
var cache = [
"",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
];
function leftPad(str, len, ch) {
// convert `str` to a `string`
str = str + "";
// `len` is the `pad`'s length now
len = len - str.length;
// doesn't need to pad
if (len <= 0) return str;
// `ch` defaults to `' '`
if (!ch && ch !== 0) ch = " ";
// convert `ch` to a `string` cuz it could be a number
ch = ch + "";
// cache common use cases
if (ch === " " && len < 10) return cache[len] + str;
// `pad` starts with an empty string
var pad = "";
// loop
while (true) {
// add `ch` to `pad` if `len` is odd
if (len & 1) pad += ch;
// divide `len` by 2, ditch the remainder
len >>= 1;
// "double" the `ch` so this operation count grows logarithmically on `len`
// each time `ch` is "doubled", the `len` would need to be "doubled" too
// similar to finding a value in binary search tree, hence O(log(n))
if (len) ch += ch;
// `len` is 0, exit the loop
else break;
}
// pad `str`!
return pad + str;
}