I need to minify a set of JSON files (language files) with Grunt/grunt-contrib-uglify:

grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    uglify: {
        build: {
            src: 'src/main/app/resources/locales/*/*.json',
            dest: 'target/resources/locales/*/*.json'
        }
    }
});

What I'm getting is:

Files: src/main/app/resources/locales/en/messages.json -> target/*/*.json
Minifying with UglifyJS...Reading src/main/app/resources/locales/en/messages.json...OK
>> Uglifying source "src/main/app/resources/locales/en/messages.json" failed.
Warning: Uglification failed. Use --force to continue.

I'm starting to wonder, does uglify work on pure JSON files, or is it intended for JavaScript source files only? The JSON file is surely well formed, it runs in the application in its non-minimized form.

I need to minify a set of JSON files (language files) with Grunt/grunt-contrib-uglify:

grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    uglify: {
        build: {
            src: 'src/main/app/resources/locales/*/*.json',
            dest: 'target/resources/locales/*/*.json'
        }
    }
});

What I'm getting is:

Files: src/main/app/resources/locales/en/messages.json -> target/*/*.json
Minifying with UglifyJS...Reading src/main/app/resources/locales/en/messages.json...OK
>> Uglifying source "src/main/app/resources/locales/en/messages.json" failed.
Warning: Uglification failed. Use --force to continue.

I'm starting to wonder, does uglify work on pure JSON files, or is it intended for JavaScript source files only? The JSON file is surely well formed, it runs in the application in its non-minimized form.

• javascript
• node.js
• gruntjs
• uglifyjs

Share Improve this question Follow asked Sep 30, 2013 at 12:30 MaDaMaDa 10.8k1010 gold badges5050 silver badges8484 bronze badges

Add a ment  | 

2 Answers 2

Sorted by: Reset to default 11

The grunt-json-minify (as indicated in user2806181's answer) works OK (thanks, by the way), but it only modifies files in place. Inspired by the answer, I've found one that's a bit more advanced: grunt-minjson:

grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    minjson: {
        build: {
            files: { 
                'target/locales/en/messages.json':
                    'resource/locales/en/messages.json'
            }
        }
    }
});

I guess UglifyJS does not work on pure JSON, because its not valid javascript.

Take a look at this link: https://github./mishoo/UglifyJS2/issues/156

But there are several grunt-plugins you can use, for example: https://npmjs/package/grunt-json-minify