Automate npm and bower install with grunt

问题

I have a node / angular project that uses npm for backend dependency management and bower for frontend dependency management. I'd like to use a grunt task to do both install commands. I haven't been able to figure out how to do it.

I made an attempt using exec, but it doesn't actually install anything.

module.exports = function(grunt) {

    grunt.registerTask('install', 'install the backend and frontend dependencies', function() {
        // adapted from http://www.dzone.com/snippets/execute-unix-command-nodejs
        var exec = require('child_process').exec,
            sys  = require('sys');

        function puts(error, stdout, stderr) { console.log(stdout); sys.puts(stdout) }

        // assuming this command is run from the root of the repo
        exec('bower install', {cwd: './frontend'}, puts);
    });

};

When I cd into frontend, open up node, and run this code from the console, this works fine. What am I doing wrong in the grunt task?

(I also tried to use the bower and npm APIs, but couldn't make that work either.)

回答1:

You need to tell grunt that you're using an async method (.exec) by calling the this.async() method, getting a callback, and calling that when exec is done.

This should work:

module.exports = function(grunt) {
    grunt.registerTask('install', 'install the backend and frontend dependencies', function() {
        var exec = require('child_process').exec;
        var cb = this.async();
        exec('bower install', {cwd: './frontend'}, function(err, stdout, stderr) {
            console.log(stdout);
            cb();
        });
    });
};

See Why doesn't my asynchronous task complete?

回答2:

To install client side components during npm install at the same time than server side libs, you can add in your package.json

"dependencies": {
    ...
    "bower" : ""
},
"scripts": {
    ...
    "postinstall" : "bower install"
}

I prefer to make the difference between install and test/build

回答3:

FYI, here is where i am for now.

You could also have taken the problem another way, i.e. let npm handle the execution of bower, and ultimately let grunt handle npm. See Use bower with heroku.

grunt.registerTask('install', 'install the backend and frontend dependencies', function() {
    var async = require('async');
    var exec = require('child_process').exec;
    var done = this.async();

    var runCmd = function(item, callback) {
        process.stdout.write('running "' + item + '"...\n');
        var cmd = exec(item);
        cmd.stdout.on('data', function (data) {
            grunt.log.writeln(data);
        });
        cmd.stderr.on('data', function (data) {
            grunt.log.errorlns(data);
        });
        cmd.on('exit', function (code) {
            if (code !== 0) throw new Error(item + ' failed');
            grunt.log.writeln('done\n');
            callback();
        });
    };

    async.series({
        npm: function(callback){
            runCmd('npm install', callback);
        },
        bower: function(callback){
            runCmd('bower install', callback);  
        }
    },
    function(err, results) {
        if (err) done(false);
        done();
    });
});