Configure grunt copy task to exclude files/folders

Question

I have installed the grunt task grunt-contrib-copy. I embedd it in my Gruntfile.js and load the task via grunt.loadNpmTasks('grunt-contrib-copy');.

Currently I use following configuration to create a folder with a subset of my js files/folders.

copy: {
            options: {
                processContent: [],
                processContentExclude: ['build/**', 'bin/**', '.*', '*.orig', '*.bak', '.*/**', '*.log', 'dist/**', 'test/**', 'dev/**', 'pyserver/**', 'node_modules/**', 'doc/**']
            },
            du: {
                files: [ 
                    {src: ['.conf1', '.conf2', './config.js'], dest: 'output/toolkit/', filter: 'isFile'},
                    {src: ['./css/**/*', './img/**/*', './js/**/*', './release/**/*', './lib/**/*', './locale/**/*'], dest: 'output/toolkit/'},
                    {expand: true, cwd: './', src: ['**'], dest: 'output/'}
                ]
            }
        }

This works fine, but everytime I run grunt copy it exits with the following error message:

Copying Gruntfile.js -> output/Gruntfile.js
Warning: Error while processing "Gruntfile.js" file. Use --force to continue.

I would like to exclude Gruntfile.js and all *.less files in js/**/*. Tried it with !(.less), !.less, !(*.less), !(./Grunfile.js), !(*Gruntfile.js) ... But nothing works. Added it to the processContentExclude array, but without success too.

So how can I exclude the Gruntfile.js and all less files in the folder structure js/**/*?

Answer 1

Found the solution:

There is no need for these lines:

files: [ 
          {src: ['.conf1', '.conf2', './config.js'], dest: 'output/toolkit/', filter: 'isFile'},
          {src: ['./css/**/*', './img/**/*', './js/**/*', './release/**/*', './lib/**/*', './locale/**/*'], dest: 'output/toolkit/'},
          {expand: true, cwd: './', src: ['**'], dest: 'output/'}
       ]

because {expand: true, cwd: './', src: ['**'], dest: 'output/'} is a new copy step, copying all files from ./ to output. Which is for me not needed, because the above lines are already copying the required files to output/toolkit.

So the following two lines does the job. No need for options or anything else. To keep out the *.less files '!**/*.less' does the job.

files: [ 
          {src: ['.conf1', '.conf2', 'config.js'], dest: 'output/toolkit/', filter: 'isFile'},
          {src: ['css/**', 'img/**', 'js/**', 'release/**', 'lib/**', 'locale/**', '!**/*.less'], dest: 'output/toolkit/'}
       ]