Files
shields/services/luarocks/luarocks-version-helpers.js

94 lines
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JavaScript

/**
* Utilities relating to Lua 'rocks' version numbers. This compares version
* numbers using the algorithm followed by luarocks command-line utility.
*
* Some specific things about LuaRocks package versioning:
*
* 1. A version string consists of two parts: the package version (version of
* the package _code_) and the revision of `rockspec` file
* https://github.com/luarocks/luarocks/wiki/Rockspec-format
* > **version** (string, mandatory field) - the version of the package,
* plus a suffix indicating the revision of the rockspec. Example:
* "2.0.1-1"
* 2. The package version (the first part of the LuaRocks version, the part
* before dash) can be anything, SemVer is not mandatory and is not used
* very often. Non-digit versions are not rare: `scm`, `dev`, `alpha`,
* etc.
* 3. `scm` (or `cvs`) is used to indicate dev version built from VCS (e.g.
* `"scm-1"`). `dev` version string is also used sometimes, and I don't
* know what the difference.
* 4. LuaRocks API does not tell you which version is the “latest”, and the
* package maintainer cannot mark a specific version as the latest. You
* should figure out it yourself.
*
* https://github.com/luarocks/luarocks/blob/405ee29ba8444d97646f62e72effeaff2bfe3f79/src/luarocks/search.lua#L182
* https://github.com/luarocks/luarocks/blob/405ee29ba8444d97646f62e72effeaff2bfe3f79/src/luarocks/core/vers.lua#L83
*/
'use strict'
const { omitv } = require('../text-formatters')
// Compare two arrays containing split and transformed to
// positive/negative numbers parts of version strings,
// respecting negative/missing values:
// [1, 2, 1] > [1, 2], but [1, 2, -1] < [1, 2] ([1, 2] is aligned to [1, 2, 0])
// Return a negative value if v1 < v2,
// zero if v1 = v2,
// a positive value otherwise.
function compareVersionLists(v1, v2) {
const maxLength = Math.max(v1.length, v2.length)
let p1, p2
for (let i = 0; i < maxLength; i++) {
p1 = v1[i] || 0
p2 = v2[i] || 0
if (p1 > p2) return 1
if (p1 < p2) return -1
}
return 0
}
// Parse a dotted version string to an array of numbers
// 'rc', 'pre', 'beta', 'alpha' are converted to negative numbers
function parseVersion(versionString) {
versionString = versionString.toLowerCase().replace('-', '.')
const versionList = []
versionString.split('.').forEach(versionPart => {
const parsedPart = /(\d*)([a-z]*)(\d*)/.exec(versionPart)
if (parsedPart[1]) {
versionList.push(parseInt(parsedPart[1]))
}
if (parsedPart[2]) {
let weight
// calculate weight as a negative number
// 'rc' > 'pre' > 'beta' > 'alpha' > any other value
switch (parsedPart[2]) {
case 'alpha':
case 'beta':
case 'pre':
case 'rc':
weight = (parsedPart[2].charCodeAt(0) - 128) * 100
break
default:
weight = -10000
}
// add positive number, i.e. 'beta5' > 'beta2'
weight += parseInt(parsedPart[3]) || 0
versionList.push(weight)
}
})
return versionList
}
function latestVersion(versions) {
return versions
.map(omitv)
.sort((a, b) => compareVersionLists(parseVersion(a), parseVersion(b)))
.pop()
}
module.exports = {
parseVersion,
compareVersionLists,
latestVersion,
}