istanbul-instrumenter-loader: coverage issues don't match source

Question

I'm using istanbul-instrumenter-loader to try to generate code coverage reports for my untranspiled es6 code, and while everything runs fine, the issues reported in the generated HTML output doesn't seem to line up with the actual source.

For example:

(in case the image is removed) A const declaration has 3 "if statement not covered" after it, even though there is no such statement or any code at all after that line. Sometimes "statement not covered" is marked in the middle of a string, or in an object declaration, or across multiple statements, etc etc.

Here's my Karma config file:

module.exports = function(config) {
    config.set({
        basePath: '../../',
        frameworks: [ 'qunit' ],

        files: [
            'test/index.js',

            // Session tickets
            { pattern: 'test/tickets/*.json', watched: true, included: false, served: true }

        ],

        preprocessors: {
            'test/index.js': 'webpack'
        },
        webpack: {
            module: {
                rules: [{
                    test: /\.js$/,
                    exclude: /node_modules/,
                    loaders: ['istanbul-instrumenter-loader', 'babel-loader']
                },
                {
                    test: /\.vue$/,
                    loaders: ['vue-loader']
                },
                {
                    test: /\.png$/,
                    loaders: ['url-loader']
                }]
            }
        },
        reporters: [ 'coverage-istanbul', 'progress' ],
        coverageIstanbulReporter: {
            type: 'html',
            dir: './coverage'
            fixWebpackSourcePaths: true
        },
        port: 9876,
        colors: true,
        logLevel: config.LOG_INFO,
        autoWatch: true,
        browsers: [ 'Chrome' ],
        browserNoActivityTimeout: 30000,
        singleRun: true,
        concurrency: Infinity,
        client: {
            captureConsole: true
        },
        browserConsoleLogOptions: {
            terminal: true,
            level: ''
        }
    })
};

I am facing similar, all my codes `else` not covered, while there is no `else` to cover. Did you resolved it? — Harry Joy, Jun 16 '17 at 18:28
Can u provide a a sample for your js file as well as the spec file — gusaindpk, Aug 22 '17 at 06:31
I have the same Issue with a typescript3/webpack4/karma3 setup — klmdb, Nov 09 '18 at 08:59

score 4 · Answer 1 · answered Jan 24 '18 at 14:48

I had a similar problem and solved it by running istanbul-instrumenter-loader before babel-loader.

You'd need to replace:

{
    test: /\.js$/,
    exclude: /node_modules/,
    loaders: ['istanbul-instrumenter-loader', 'babel-loader']
}

with:

{
    test: /\.js$/,
    exclude: /node_modules/,
    use: [
        {
            loader: 'babel-loader'
        },
        {
            loader: 'istanbul-instrumenter-loader',
            options: {
                esModules: true
            }
        }
    ]
}

score 0 · Answer 2 · answered Aug 22 '17 at 09:39

0

karma-coverage and karma-webpack seem to be working together

"karma": "^0.12.28",
"karma-coverage": "^0.2.7",
"karma-sourcemap-loader": "^0.3.2",
"karma-webpack": "^1.3.1",
"webpack": "^1.4.14"

Have you configured correctly , you can get more here https://github.com/webpack-contrib/istanbul-instrumenter-loader

and can u provide a a sample for your js file/spec

answered Aug 22 '17 at 09:39

Monis Majeed

1,358
14
21

I don't know if I've configured correctly, that's part of the question. I did post my configuration, though. – tacospice Aug 23 '17 at 14:13

istanbul-instrumenter-loader: coverage issues don't match source

2 Answers2