Files
shields/lib/luarocks-version.js
T

60 lines
1.8 KiB
JavaScript

/**
* Utilities relating to Lua 'rocks' version numbers.
* This compares version numbers using the algorithm
* followed by luarocks command-line utility
*/
'use strict';
// Compare two arrays containing splitted 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;
}
exports.compareVersionLists = compareVersionLists;
// 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('-', '.');
let versionList = [];
versionString.split('.').forEach(function(versionPart) {
let 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;
}
exports.parseVersion = parseVersion;