gulpfile.js

const gulp = require("gulp");
const less = require("gulp-less");
const rename = require('gulp-rename');
const rm = require("rimraf");
const cleanCSS = require('gulp-clean-css');
const {watch, task, series, parallel} = gulp;
const lessGlob = ["src/**.less","!**/tool.less"];

function swallowError(error){
    console.error("已捕获错误:",error.toString());
}

const getLessBuilder = async (src, distName)=>{
    await gulp
        .src(src)
        .pipe(less({}))
        .pipe(rename(file=>{
            file.basename = `${distName}.uncompressed`;
        }))
        .pipe(gulp.dest("dist"))
        .pipe(
            cleanCSS({
                backgroundClipMerging: true, // controls background-clip merging into shorthand
                backgroundOriginMerging: true, // controls background-origin merging into shorthand
                backgroundSizeMerging: true, // controls background-size merging into shorthand
                colors: true, // controls color optimizations
                ieBangHack: false, // controls keeping IE bang hack
                ieFilters: false, // controls keeping IE `filter` / `-ms-filter`
                iePrefixHack: false, // controls keeping IE prefix hack
                ieSuffixHack: false, // controls keeping IE suffix hack
                merging: true, // controls property merging based on understandability
                shorterLengthUnits: false, // controls shortening pixel units into `pc`, `pt`, or `in` units
                spaceAfterClosingBrace: true, // controls keeping space after closing brace - `url() no-repeat` into `url()no-repeat`
                urlQuotes: true, // controls keeping quoting inside `url()`
                zeroUnits: true // controls removal of units `0` value
            })
        )
        .on("error",swallowError)
        .pipe(rename(function(file){
            file.basename = distName;
        }))
        .pipe(gulp.dest("dist"))
}


gulp.task("build-less",async function(){
    await new Promise(resolve=> rm("dist", resolve));
    await getLessBuilder("src/dist-index.less","index");
    await getLessBuilder("src/dist-lite.less","lite");
    await getLessBuilder("src/dist-reset.less","reset");
});


task("watch-less", function () {
    watch(lessGlob, series(["build-less"]));
});