Create matching file names in Grunt - gruntjs

Question

I've got several projects that each use an identical Gruntfile to run tasks and put the output in their own dist folder. Folder setup:
MyProjects
- Project1
- src
- dist
- Project2
- src
- dist
.....
I can't figure out how to run Grunt at the top level (MyProjects) and still have the output generated in the correct dist folder dynamically.
Is there a way I can have Grunt put the output in the correct dist folder without having to hard code it into the Gruntfile? Something like:
dist: {
files: {
// destination : source js
'<% ProjectName %>/dist/app.js': '<% ProjectName %>/src/app.js'
},
Thanks
module.exports = function (grunt) {
require('load-grunt-tasks')(grunt);
// Project configuration.
grunt.initConfig({
watch: {
scripts: {
files: ['src/**/*.js'],
tasks: ['browserify', 'file_append', 'concat'],
options: {
spawn: false
}
},
sass: {
files: "src/scss/*.scss",
tasks: ['sass', 'file_append', 'concat']
}
},
sass: {
dist: {
options: {
style: 'expanded'
},
files: {
// destination // source file
"format/css/styles.css": "src/scss/styles.scss"
}
},
options: {
sourcemap: "none",
style: "compact",
noCache: true
}
},
file_append: {
default_options: {
files: [
// Development build
{
append: "",
prepend: "",
input: "format/app.js",
output: "format/dev.app.js"
},
{
append: "</style>`)",
prepend: "document.body.insertAdjacentHTML('afterbegin', `\n<style>\n",
input: "format/css/styles.css",
output: "format/css/dev.styles.html"
},
// Production build
{
append: "</script>",
prepend: "<script>\n",
input: "format/app.js",
output: "format/prod.app.html"
},
{
append: "</style>",
prepend: "<style>\n",
input: "format/css/styles.css",
output: "format/css/prod.styles.html"
}
]
}
},
concat: {
options: {
seperator: '\n'
},
// Development build
dev: {
src: ['format/dev.app.js', 'format/css/dev.styles.html'],
dest: 'dev/dev.app.js'
},
// Production build
prod: {
src: ['format/prod.app.html', 'format/css/prod.styles.html'],
dest: 'dist/prod.app.html'
}
},
browserify: {
dist: {
files: {
// destination for transpiled js : source js
'format/app.js': 'src/app.js'
},
options: {
transform: [
[
'babelify', {
presets: "es2015",
comments: false,
plugins: "transform-object-rest-spread"
}
]
],
browserifyOptions: {
debug: false
}
}
}
}
});
grunt.registerTask('default', [
'sass',
'browserify:dist',
'file_append',
'concat',
'watch'
]);
};

Answer 1

There's a couple ways you can tackle this.
One option is to overload the arguments you pass to the task & include the folder name you wish to target.
grunt sass:dist:Project1
The additional argument is accessible via lodash templates which are a part of the GruntJS framework, and allows the configuration to be set at the time the task is ran:
sass: {
dist: {
options: {
style: 'expanded'
},
files: {
// destination // source file
"MyProjects/<%= grunt.task.current.args[0] %>/format/css/styles.css": "MyProjects/<%= grunt.task.current.args[0] %>/src/scss/styles.scss"
}
},
options: {
sourcemap: "none",
style: "compact",
noCache: true
}
}
This approach works in the context of the function that's executing, but it wouldn't continue to pass the args to the next task. To do that, we need to add a custom task which will set a configuration object before executing the task list:
grunt.registerTask("build", (project) => {
const buildConfig = { project };
grunt.config.set("build", buildConfig);
grunt.task.run([
'sass',
'browserify:dist',
'file_append',
'concat',
'watch'
]);
});
Now when we run grunt build:Project1, your custom task build will run and set the property we passed in the grunt config object. We can then reference that value in our other grunt config objects using lodash like we did for the first option. To access config values with lodash templates, we just have to provide the config pointer in json notation:
files: {
"MyProjects/<%= build.project %>/format/css/styles.css": "MyProjects/<%= build.project %>/src/scss/styles.scss"
}
Grunt compiles the configs required for a task at the time they're run & will process the lodash templates then, allowing you to inject your project name into a task. Since we stored the value in the config object, the value will persist through until grunt completes and exits.