Gulp on Error is not executing

[manik-ushur]

Hi,
I have a backbone js project, where I am using gulp to bundle/obfuscate it using plugins. Sometimes, my code is encountering errors with build. But those are not spitted outside, though are shown up in console. My CI/CD pipeline misses it out.

My env:
Gulp version: 4.0.2
Node version: 10.16.3

This is the code I am using:

var gulp = require('gulp'),
minifycss = require('gulp-minify-css'),
concat = require('gulp-concat');

gulp.task('vendorcss', function() {
    return gulp.src(vendorcsslist) //json based list
      .pipe(concat('vendor.min.css'))
      .pipe(minifycss().on('error', function(err){
        console.log("ERROR", err);
      }))
      .pipe(gulp.dest('dist/target/css'));
  });

I am not able to reach to the error method, even though an error is raised by minifycss.

[09:51:24] 'vendorcss' errored after 445 ms
[09:51:24] TypeError: Cannot read property 'indexOf' of undefined
    at /Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/selectors/optimizers/simple.js:140:21
    at String.replace (<anonymous>)
    at colorMininifier (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/selectors/optimizers/simple.js:134:6)
    at reduce (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/selectors/optimizers/simple.js:197:13)
    at _optimize (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/selectors/optimizers/simple.js:231:23)
    at SimpleOptimizer.optimize (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/selectors/optimizers/simple.js:263:3)
    at SelectorsOptimizer.process (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/selectors/optimizer.js:13:37)
    at /Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/clean.js:170:31
    at run (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/clean.js:149:7)
    at minify (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/clean.js:161:3)
    at whenSourceMapReady (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/clean.js:85:7)
    at Object.whenDone (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/clean.js:98:14)
    at processNext (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/imports/inliner.js:105:13)
    at importFrom (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/imports/inliner.js:79:10)
    at ImportInliner.process (/Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/imports/inliner.js:36:10)
    at /Users/manikmittal/Documents/work/official/source-code/mobilyzeclient/node_modules/clean-css/lib/clean.js:71:41
[09:51:24] 'dist' errored after 468 ms

Is this something I am doing wrong here? Pl suggest.

[begin-again]

you could try pipeline instead of pipe

[manik-ushur]

Can you share any example?

[begin-again]

• Discussion about pipeline being preferred over pipe (https://github.com/orgs/gulpjs/discussions/2586)
• good write up on pipelines