feat: support monocart report

README.md

@@ -43,6 +43,7 @@ Here is a list of common options. Run `c8 --help` for the full list and document
 | `--per-file` | check thresholds per file | `boolean` | `false` |
 | `--temp-directory` | directory V8 coverage data is written to and read from | `string` | `process.env.NODE_V8_COVERAGE` |
 | `--clean` | should temp files be deleted before script execution | `boolean` | `true` |
+| `--experimental-monocart` | see [section below](#using-monocart-coverage-reports-experimental) for more info | `boolean` | `false` |
 
 ## Checking for "full" source coverage using `--all`
 
@@ -119,6 +120,12 @@ The `--100` flag can be set for the `check-coverage` as well:
 c8 check-coverage --100
 ```
 
+## Using Monocart coverage reports (experimental)
+[Monocart](https://github.com/cenfun/monocart-coverage-reports) will bring additional support for native V8 coverage reports, for example:
+```sh
+c8 --experimental-monocart --reporter=v8 --reporter=console-details node foo.js
+```
+
 ## Ignoring Uncovered Lines, Functions, and Blocks
 
 Sometimes you might find yourself wanting to ignore uncovered portions of your

lib/commands/report.js

@@ -1,5 +1,6 @@
 const { checkCoverages } = require('./check-coverage')
 const Report = require('../report')
+const monocartReport = require('../monocart-report')
 
 exports.command = 'report'
 
@@ -18,6 +19,12 @@ exports.outputReport = async function (argv) {
     argv.branches = 100
     argv.statements = 100
   }
+
+  if (argv.experimentalMonocart || process.env.EXPERIMENTAL_MONOCART) {
+    await monocartReport(argv)
+    return
+  }
+
   const report = Report({
     include: argv.include,
     exclude: argv.exclude,

lib/monocart-report.js

@@ -0,0 +1,165 @@
+const Exclude = require('test-exclude')
+const path = require('path')
+const { fileURLToPath } = require('url')
+
+const { CoverageReport } = require('monocart-coverage-reports')
+
+module.exports = async (argv) => {
+  // console.log(argv);
+  const exclude = new Exclude({
+    exclude: argv.exclude,
+    include: argv.include,
+    extension: argv.extension,
+    relativePath: !argv.allowExternal,
+    excludeNodeModules: argv.excludeNodeModules
+  })
+
+  // adapt coverage options
+  const coverageOptions = getCoverageOptions(argv, exclude)
+  const coverageReport = new CoverageReport(coverageOptions)
+  coverageReport.cleanCache()
+
+  // read v8 coverage data from tempDirectory
+  await coverageReport.addFromDir(argv.tempDirectory)
+
+  // generate report
+  await coverageReport.generate()
+}
+
+function getReports (argv) {
+  const reports = Array.isArray(argv.reporter) ? argv.reporter : [argv.reporter]
+  const reporterOptions = argv.reporterOptions || {}
+
+  return reports.map((reportName) => {
+    const reportOptions = {
+      ...reporterOptions[reportName]
+    }
+    if (reportName === 'text') {
+      reportOptions.skipEmpty = false
+      reportOptions.skipFull = argv.skipFull
+      reportOptions.maxCols = process.stdout.columns || 100
+    }
+    return [reportName, reportOptions]
+  })
+}
+
+// --all: add empty coverage for all files
+function getAllOptions (argv, exclude) {
+  if (!argv.all) {
+    return
+  }
+
+  const src = argv.src
+  const workingDirs = Array.isArray(src) ? src : (typeof src === 'string' ? [src] : [process.cwd()])
+  return {
+    dir: workingDirs,
+    filter: (filePath) => {
+      return exclude.shouldInstrument(filePath)
+    }
+  }
+}
+
+function getEntryFilter (argv, exclude) {
+  if (argv.entryFilter) {
+    return argv.entryFilter
+  }
+  return (entry) => {
+    return exclude.shouldInstrument(fileURLToPath(entry.url))
+  }
+}
+
+function getSourceFilter (argv, exclude) {
+  if (argv.sourceFilter) {
+    return argv.sourceFilter
+  }
+  return (sourcePath) => {
+    if (argv.excludeAfterRemap) {
+      // console.log(sourcePath)
+      return exclude.shouldInstrument(sourcePath)
+    }
+    return true
+  }
+}
+
+function getCoverageOptions (argv, exclude) {
+  const reports = getReports(argv)
+  const allOptions = getAllOptions(argv, exclude)
+
+  return {
+    logging: argv.logging,
+    name: argv.name,
+    inline: argv.inline,
+    lcov: argv.lcov,
+    outputDir: argv.reportsDir,
+    clean: argv.clean,
+
+    reports,
+    all: allOptions,
+
+    // use default value for istanbul
+    defaultSummarizer: 'pkg',
+
+    entryFilter: getEntryFilter(argv, exclude),
+
+    sourceFilter: getSourceFilter(argv, exclude),
+
+    // sourcePath: (filePath) => {
+    //   return path.resolve(filePath);
+    // },
+
+    onEnd: (coverageResults) => {
+      // console.log(`Coverage report generated: ${coverageResults.reportPath}`);
+
+      if (!argv.checkCoverage) {
+        return
+      }
+
+      // check thresholds
+      const thresholds = {}
+      const metrics = ['bytes', 'statements', 'branches', 'functions', 'lines']
+      metrics.forEach((k) => {
+        if (argv[k]) {
+          thresholds[k] = argv[k]
+        }
+      })
+
+      const { summary, files } = coverageResults
+
+      if (argv.perFile) {
+        files.forEach((file) => {
+          checkCoverage(file.summary, thresholds, file)
+        })
+      } else {
+        checkCoverage(summary, thresholds)
+      }
+    }
+  }
+}
+
+function checkCoverage (summary, thresholds, file) {
+  if (file && file.empty) {
+    process.exitCode = 1
+    console.error(
+      'ERROR: Empty coverage (untested file) does not meet threshold for ' +
+        path.relative('./', file.sourcePath).replace(/\\/g, '/')
+    )
+    return
+  }
+  Object.keys(thresholds).forEach(key => {
+    const coverage = summary[key].pct
+    if (typeof coverage !== 'number') {
+      return
+    }
+    if (coverage < thresholds[key]) {
+      process.exitCode = 1
+      if (file) {
+        console.error(
+          'ERROR: Coverage for ' + key + ' (' + coverage + '%) does not meet threshold (' + thresholds[key] + '%) for ' +
+            path.relative('./', file.sourcePath).replace(/\\/g, '/') // standardize path for Windows.
+        )
+      } else {
+        console.error('ERROR: Coverage for ' + key + ' (' + coverage + '%) does not meet global threshold (' + thresholds[key] + '%)')
+      }
+    }
+  })
+}

lib/parse-args.js

@@ -158,6 +158,11 @@ function buildYargs (withCommands = false) {
       describe: 'supplying --merge-async will merge all v8 coverage reports asynchronously and incrementally. ' +
         'This is to avoid OOM issues with Node.js runtime.'
     })
+    .option('experimental-monocart', {
+      default: false,
+      type: 'boolean',
+      describe: 'Using Monocart coverage reports'
+    })
     .pkgConf('c8')
     .demandCommand(1)
     .check((argv) => {