v8-to-istanbul
Advanced tools
Package description
The v8-to-istanbul package is a tool that converts V8 coverage information into a format that is compatible with Istanbul's coverage reports. It allows developers to generate coverage reports for JavaScript code executed in the V8 JavaScript engine, which is used by Node.js and Chrome.
Convert V8 coverage to Istanbul format
This feature allows you to convert V8 coverage information into the Istanbul format. You can then use this data to generate reports with Istanbul-compatible tools.
const v8toIstanbul = require('v8-to-istanbul');
const scriptPath = './path/to/script.js';
const v8Coverage = require('./path/to/v8-coverage.json');
const converter = v8toIstanbul(scriptPath);
converter.load();
converter.applyCoverage(v8Coverage);
const istanbulCoverage = converter.toIstanbul();
console.log(JSON.stringify(istanbulCoverage, null, 2));Exclude specific functions or lines from coverage
This feature allows you to exclude specific functions or ranges of lines from the coverage report. This is useful for ignoring code that you do not want to include in your coverage metrics.
const v8toIstanbul = require('v8-to-istanbul');
const scriptPath = './path/to/script.js';
const converter = v8toIstanbul(scriptPath, {
exclude: ['**/node_modules/**', '**/test/**']
});
converter.exclude('functionName');
converter.excludeRange([startLine, endLine]);nyc is a command-line tool and library for instrumenting code with Istanbul's coverage tracking and reporting. It is a more comprehensive tool that includes v8-to-istanbul's functionality as part of its coverage processing pipeline.
c8 is a higher-level tool that uses v8-to-istanbul under the hood to collect and report V8 code coverage. It provides a simple command-line interface to generate coverage reports without needing to manually convert V8 coverage data.
istanbul-lib-instrument is part of the Istanbul API and is responsible for instrumenting JavaScript code. It differs from v8-to-istanbul in that it modifies the code to track coverage, rather than converting coverage data from the V8 engine.
Readme
converts from v8 coverage format to istanbul's coverage format.
const v8toIstanbul = require('v8-to-istanbul')
// the path to the original source-file is required, as its contents are
// used during the conversion algorithm.
const converter = v8toIstanbul('./path-to-instrumented-file.js')
await converter.load() // this is required due to async file reading.
// provide an array of coverage information in v8 format.
converter.applyCoverage([
{
"functionName": "",
"ranges": [
{
"startOffset": 0,
"endOffset": 520,
"count": 1
}
],
"isBlockCoverage": true
},
// ...
])
// output coverage information in a form that can
// be consumed by Istanbul.
console.info(JSON.stringify(converter.toIstanbul()))
Sometimes you might find yourself wanting to ignore uncovered lines in your application (for example, perhaps you run your tests in Linux, but there's code that only executes on Windows).
To ignore lines, use the special comment /* c8 ignore next */.
const myVariable = 99
/* c8 ignore next */
if (process.platform === 'win32') console.info('hello world')
const myVariable = 99
/* c8 ignore next 3 */
if (process.platform === 'win32') {
console.info('hello world')
}
/* c8 ignore start */
function dontMindMe() {
// ...
}
/* c8 ignore stop */
const myVariable = 99
const os = process.platform === 'darwin' ? 'OSXy' /* c8 ignore next */ : 'Windowsy'
To execute tests, simply run:
npm test
FAQs
convert from v8 coverage format to istanbul's format
The npm package v8-to-istanbul receives a total of 14,650,130 weekly downloads. As such, v8-to-istanbul popularity was classified as popular.
We found that v8-to-istanbul demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
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