grunt will not run on my project, which default Task? - gruntjs

Question

I am trying to run grunt in order to get SASS and a few other things to compile my project (that someone else created), however I keep getting the following error:
Warning: Task "default" not found. Use --force to continue.
Aborted due to warnings.
I do not understand which "default" task it is is referring to. The grunt file I have inherited is as follows:
module.exports = function(grunt) {
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
concat: {
options: {
separator: ';'
},
dev: {
src: ['www/_assets/js/vendor-concat/*.js', 'www/_assets/js/*.js', '!www/_assets/js/prototype.js', '!www/_assets/js/scripts.js', '!www/_assets/js/scripts.min.js'],
dest: 'www/_assets/js/scripts.js'
}
},
uglify: {
dist: {
files: {
'www/_assets/js/scripts.min.js': ['www/_assets/js/scripts.js']
}
}
},
jshint: {
files: ['Gruntfile.js'],
options: {
// options here to override JSHint defaults
globals: {
jQuery: true,
console: true,
module: true,
document: true
}
}
},
modernizr: {
dist: {
// [REQUIRED] Path to the build you're using for development.
"devFile" : "www/_assets/js/vendor/modernizr-2.7.1.js",
// [REQUIRED] Path to save out the built file.
"outputFile" : "www/_assets/js/vendor/modernizr-custom.js"
}
},
imageoptim: {
dev: {
src: ['www/_assets/img']
}
},
sass: {
dev: {
options: {
includePaths: ['www/_assets/scss'],
outputStyle: 'compressed',
sourceMap: true
},
files: {
'www/_assets/css/main.css' : 'www/_assets/scss/main.scss',
'www/_assets/css/main-ie8.css' : 'www/_assets/scss/main-ie8.scss'
}
}
},
assemble: {
options: {
flatten: false,
expand: true,
assets: 'www/_assets',
layout: 'default.hbs',
layoutdir: 'www/_templates/layouts',
partials: ['www/_templates/partials/*.hbs'],
data: ['www/_templates/data/*.json']
},
dev: {
files: [
{expand: true, cwd: 'www/_templates/pages/', src: '**/*.hbs', dest: 'www/', ext: '.html'}
]
}
},
watch: {
options: {
livereload: true,
spawn: false
},
css: {
files: ['www/_assets/scss/**/*.scss'],
tasks: ['sass']
},
js: {
files: ['www/_assets/js/**/*.js', '!www/_assets/js/scripts.min.js', '!www/_assets/js/scripts.js'],
tasks: ['jshint', 'concat:dev']
},
hbs: {
files: ['www/_templates/{,*/}*.hbs', 'www/_templates/{,*/*/}*.hbs', 'www/_templates/{,*/*/*/}*.hbs'],
tasks: ['assemble']
},
html: {
files: ['www/email.html']
}
},
copyto: {
prototype: {
files: [
{cwd: 'www/', src: ['**/*'], dest: 'prototype/'}
],
options: {
ignore: [
'www/_assets/scss{,/**/*}',
'www/_assets/js{,/**/*}',
'!www/_assets/js/vendor{,/**/*}',
'!www/_assets/js/scripts.min.js',
'!www/_assets/js/prototype.js',
'www/_templates{,/**/*}',
'www/z-backups{,/**/*}',
'www/_assets/css/*.map'
]
}
},
beta: {
files: [
{cwd: 'prototype/_assets/', src: ['**/*'], dest: '_beta-sln/Beta/src/SFA.as.Web.Candidate/Content/_assets/'}
],
options: {
ignore: [
'prototype/_assets/video{,/**/*}',
'prototype/_assets/js/prototype.js'
]
}
},
sprint: {
files: [
{cwd: 'prototype/', src: ['**/*'], dest: 'sprint/'}
]
},
dist: {
files: [
{cwd: 'www/', src: ['**/*'], dest: 'dist/'}
],
options: {
ignore: [
'www/_assets/scss{,/**/*}',
'www/_assets/css/*.map',
'www/_assets/video{,/**/*}',
'www/_assets/js/plugins{,/**/*}',
'www/_assets/js/interactions.js',
'www/_assets/js/scripts.js',
'www/_templates{,/**/*}',
'www/*.html',
'!www/index.html',
'www/z-backups{,/**/*}'
]
}
}
},
clean: {
prototype: {
src: [ 'prototype/' ]
},
sprint: {
src: [ 'sprint/' ]
},
dist: {
src: [ 'dist/' ]
}
},
replace: {
map: {
src: ['www/_assets/css/*.css'],
overwrite: true,
replacements: [{
from: 'sourceMappingURL=main.css.map',
to: 'Map removed'
},{
from: 'sourceMappingURL=main-ie8.css.map',
to: 'Map removed'
}]
},
scripts: {
src: ['www/apprentice/*.html', 'www/test/apprentice/*.html', 'www/trainee/*.html', 'www/employer/*.html', 'www/*.html'],
overwrite: true,
replacements: [{
from: 'scripts.js',
to: 'scripts.min.js'
}]
}
},
prettify: {
options: {
indent: 2,
wrap_line_length: 78,
brace_style: 'expand',
},
// Specify a number to padcomments
dist: {
files: [
{expand: true, cwd: 'dist/', src: ['apprentice/*.html', 'trainee/*.html', 'employer/*.html', '*.html'], dest: 'dist/', ext: '.html'}
]
},
prototype: {
files: [
{expand: true, cwd: 'prototype/', src: ['apprentice/*.html', 'trainee/*.html', 'employer/*.html', '*.html', '!pattern-library.html'], dest: 'prototype/', ext: '.html'}
]
}
},
devUpdate: {
main: {
options: {
updateType: 'report', //just report outdated packages
reportUpdated: false, //don't report already updated packages
semver: true, //use package.json semver rules when updating
packages: { //what packages to check
devDependencies: true, //only devDependencies
dependencies: false
},
packageJson: null //find package.json automatically
}
}
},
browserSync: {
dev: {
bsFiles: {
src : [
'www/_assets/css/*.css',
'www/_assets/js/scripts.js',
'www/**/*.html'
]
},
options: {
ghostMode: {
clicks: true,
scroll: true,
links: true,
forms: true
},
watchTask: true,
server: {
baseDir: "www"
}
}
}
},
connect: {
server: {
options: {
port: 7000,
base: 'www',
livereload: true,
open: true
}
}
},
uncss: {
offline: {
options: {
// csspath : 'www/_assets/css/',
// urls : ['http://localhost:/mypage', '...'], // Deprecated
timeout : 1000,
},
files: {
'www/offline/offline.css': ['www/offline/maintenance.html']
}
}
}
});
[
'assemble',
'grunt-modernizr',
'grunt-contrib-imagemin',
'grunt-imageoptim',
'grunt-contrib-uglify',
'grunt-contrib-jshint',
'grunt-sass',
'grunt-uncss',
'grunt-criticalcss',
'grunt-contrib-concat',
'grunt-text-replace',
'grunt-contrib-watch',
'grunt-copy-to',
'grunt-contrib-clean',
'grunt-contrib-compress',
'grunt-pngmin',
'grunt-browser-sync',
'grunt-dev-update',
'grunt-contrib-connect',
'grunt-prettify'
].forEach(function (task) {
grunt.loadNpmTasks(task);
});
grunt.registerTask('images', ['imageoptim']);
grunt.registerTask('modern', ['modernizr']);
grunt.registerTask('offline', ['uncss:offline']);
grunt.registerTask('dev', ['jshint', 'concat:dev', 'sass', 'assemble', 'connect', 'watch']);
grunt.registerTask('sync', ['jshint', 'concat:dev', 'sass', 'assemble', 'browserSync', 'watch']);
grunt.registerTask('proto', ['uglify:dist', 'replace:map', 'clean:prototype', 'replace:scripts', 'copyto:prototype', 'prettify:prototype']);
grunt.registerTask('sprint', ['clean:sprint', 'copyto:sprint']);
grunt.registerTask('dist', ['uglify:dist', 'replace:map', 'clean:dist', 'replace:scripts', 'copyto:dist', 'prettify:dist']);
grunt.registerTask('beta', ['copyto:beta']);
};
As I have not created this myself, I am reluctant to go ahead and break it but is there anything there which stands out? I have seen similar questions but as the grunt files need to vary it is difficult to find the correct answer for this.
Many thanks!

Answer 1

Since file doesn't have default task you have to either create it or run grunt with one of defined tasks:
> grunt dev
or add default task in your Gruntfile.js
grunt.registerTask('default',['dev']);
please refer to http://gruntjs.com/creating-tasks for more information