Create two configurations for a grunt plug-in that is not multi-taskable - gruntjs

Question

I use a grunt package called grunt-preprocess, Obviously, it doesn't support multi-tasks.
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
preprocess: {
options: {
context: {
ENV: grunt.option('env') || 'prod'
},
},
all_from_dir: {
src: '*.*',
cwd: 'src/',
dest: 'src',
expand: true
}
},
})
Now I want to execute preprocess twice, once from the src directory, and once from the dist directory. How should I configure this package to achieve that?
I have tried this configuration;
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
preprocess: {
first: {
options: {
context: {
ENV: grunt.option('env') || 'prod'
},
},
all_from_dir: {
src: '*.*',
cwd: 'src/',
dest: 'src',
expand: true
}
},
second: {
options: {
context: {
ENV: grunt.option('env') || 'prod'
},
},
all_from_dir: {
src: '*.*',
cwd: 'dist/',
dest: 'dist',
expand: true
}
}
}
})
and then execute grunt preprocess:first. However it does not work:
PS D:\workspace\environment-compile> grunt preprocess:first
Running "preprocess:first" (preprocess) task
Done.

Answer 1

Yes, you're right preprocess is single Task only, therefore doesn't allow multiple targets to be defined.
You'll need to create another custom task that dynamically configures the preprocess Task and then runs it.
For example:
Gruntfile.js
module.exports = function (grunt) {
grunt.loadNpmTasks('grunt-preprocess');
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
preprocess: {
options: {
context: {
ENV: grunt.option('env') || 'prod'
},
},
all_from_dir: {
src: '*.*',
cwd: 'src/',
dest: 'src',
expand: true
}
},
// ...
});
// Custom task dynamically configures the `preprocess` Task and runs it.
grunt.registerTask('preprocess_dist', function() {
grunt.config.set('preprocess.all_from_dir.cwd', 'dist/');
grunt.config.set('preprocess.all_from_dir.dest', 'dist');
grunt.task.run(['preprocess']);
});
grunt.registerTask('preprocessBoth', [ 'preprocess', 'preprocess_dist' ]);
};
Running:
Via your CLI run the following single command to execute the preprocess task twice, once from the src directory, once from the dist directory:
grunt preprocessBoth
Explanation:
The custom Task named preprocess_dist dynamically configures the values for the cwd and dest properties, setting them to 'dist/' and 'dist' respectively. This is done via the grunt.config.set method
Then the task is run via the grunt.task.run method.
The last line of code that reads:
grunt.registerTask('preprocessBoth', [ 'preprocess', 'preprocess_dist' ]);
creates a task named preprocessBoth and adds the following two tasks to to the taskList:
preprocess
preprocess_dist
Essentially what happens when you run grunt preprocessBoth is:
The preprocess task runs using files from the src directory.
Then the custom preprocess_dist task runs using files from the dist directory.
If you prefer, you can also run each task independently via CLI, i.e:
grunt preprocess
and
grunt preprocess_dist