karma-concat-preprocessor

File concatenation preprocessor for Karma JavaScript runner

Installation

npm install karma-concat-preprocessor --save-dev

Configuration

The preprocessor must be configured in the karma.conf.js file.

Firstly, you will need to include entries in the plugins property and preprocessors property:

plugins: [
'karma-concat-preprocessor'
],
preprocessors: {
'*/': ['concat']
}

It's ok to allow all files to be processed by the concat preprocessor since it will only affect the files it has been configured to concatenate.

$3

Include the output file in the files property but do not add the files that will be concatenated into it:

files: [
'concats/concatenated.js'
]

$3

Now you will need to configure which files will be concatenated into the output(s).

concat: {

// array of output configurations.
outputs: [

// output file configuration
{
file: 'concats/concatenated.js' // The output file (cannot be a glob)
inputs: [
'src/file1.js',
'src/file2.js',
'src/file3.js',
'src/file4.js'
]
},

// Additional output configuration. More than 1 concatenation can be specified by adding
// additional items to the array: (Don't forget to add the output file to the 'files' property)
{
file: 'concats/concatenated2.js' // The output file
inputs: [
'src/*/.js'
]
},
]
}

$3

By default, the header and footer of the output file is a javascript closure:

(function() { //header
/ concatenated files /
}());

You can change these by adding the header and/or footer property to the concat configuration property:

concat: {
header: '/ My header /',
footer: '/ My Footer /'
}

You can also specify header and/or footer per output file:

concat: {
outputs: [
{
header: '/ My header /',
footer: '/ My Footer /',
file: 'concats/concatenated.js' // The output file
inputs: [
'src/*/.js'
]
}
]
}