feat: merge nyc options from multiple files (cypress-io#205)

Merges NYC settings from
- defaults
- .nycrc
- .nycrc.json
- package.json nyc object

Author: bahmutov

.circleci/config.yml

@@ -369,6 +369,7 @@ workflows:
           store_artifacts: true
           post-steps:
             - run: cat examples/exclude-files/.nyc_output/out.json
+            - run: cat examples/exclude-files/coverage/coverage-final.json
             # store the created coverage report folder
             # you can click on it in the CircleCI UI
             # to see live static HTML site
@@ -380,9 +381,11 @@ workflows:
                 working_directory: examples/exclude-files
             - run:
                 name: Check code coverage 📈
+                # we will check the final coverage report
+                # to make sure it only has files we are interested in
                 command: |
                   ../../node_modules/.bin/check-coverage main.js
-                  ../../node_modules/.bin/only-covered main.js
+                  ../../node_modules/.bin/only-covered --from coverage/coverage-final.json main.js
                 working_directory: examples/exclude-files
 
       - cypress/run:

.nycrc.json

@@ -0,0 +1,6 @@
+{
+  "exclude": [
+    "support-utils.js",
+    "task-utils.js"
+  ]
+}

cypress/integration/combine-spec.js

@@ -0,0 +1,66 @@
+const { combineNycOptions, defaultNycOptions } = require('../../task-utils')
+describe('Combine NYC options', () => {
+  it('overrides defaults', () => {
+    const pkgNycOptions = {
+      extends: '@istanbuljs/nyc-config-typescript',
+      all: true
+    }
+    const combined = combineNycOptions({
+      pkgNycOptions,
+      defaultNycOptions
+    })
+    cy.wrap(combined).should('deep.equal', {
+      extends: '@istanbuljs/nyc-config-typescript',
+      all: true,
+      'report-dir': './coverage',
+      reporter: ['lcov', 'clover', 'json'],
+      extension: ['.js', '.cjs', '.mjs', '.ts', '.tsx', '.jsx'],
+      excludeAfterRemap: true
+    })
+  })
+
+  it('allows to specify reporter, but changes to array', () => {
+    const pkgNycOptions = {
+      reporter: 'text'
+    }
+    const combined = combineNycOptions({
+      pkgNycOptions,
+      defaultNycOptions
+    })
+    cy.wrap(combined).should('deep.equal', {
+      'report-dir': './coverage',
+      reporter: ['text'],
+      extension: ['.js', '.cjs', '.mjs', '.ts', '.tsx', '.jsx'],
+      excludeAfterRemap: true
+    })
+  })
+
+  it('combines multiple options', () => {
+    const pkgNycOptions = {
+      all: true,
+      extension: '.js'
+    }
+    const nycrc = {
+      include: ['foo.js']
+    }
+    const nycrcJson = {
+      exclude: ['bar.js'],
+      reporter: ['json']
+    }
+    const combined = combineNycOptions({
+      pkgNycOptions,
+      nycrc,
+      nycrcJson,
+      defaultNycOptions
+    })
+    cy.wrap(combined).should('deep.equal', {
+      all: true,
+      'report-dir': './coverage',
+      reporter: ['json'],
+      extension: ['.js'],
+      excludeAfterRemap: true,
+      include: ['foo.js'],
+      exclude: ['bar.js']
+    })
+  })
+})

package-lock.json

@@ -58,7 +58,7 @@
     "@cypress/webpack-preprocessor": "5.1.2",
     "babel-loader": "8.1.0",
     "babel-plugin-istanbul": "6.0.0",
-    "check-code-coverage": "1.0.1",
+    "check-code-coverage": "1.1.0",
     "console-log-div": "0.6.3",
     "cypress": "4.4.0",
     "express": "4.17.1",
@@ -72,10 +72,5 @@
     "typescript": "3.8.3",
     "webpack": "4.42.1",
     "webpack-cli": "3.3.11"
-  },
-  "nyc": {
-    "exclude": [
-      "utils.js"
-    ]
   }
 }

package.json

@@ -7,6 +7,66 @@ const { readFileSync, writeFileSync, existsSync } = require('fs')
 const { isAbsolute, resolve, join } = require('path')
 const debug = require('debug')('code-coverage')
 
+function combineNycOptions({
+  pkgNycOptions,
+  nycrc,
+  nycrcJson,
+  defaultNycOptions
+}) {
+  // last option wins
+  const nycOptions = Object.assign(
+    {},
+    defaultNycOptions,
+    nycrc,
+    nycrcJson,
+    pkgNycOptions
+  )
+
+  if (typeof nycOptions.reporter === 'string') {
+    nycOptions.reporter = [nycOptions.reporter]
+  }
+  if (typeof nycOptions.extension === 'string') {
+    nycOptions.extension = [nycOptions.extension]
+  }
+
+  return nycOptions
+}
+
+const defaultNycOptions = {
+  'report-dir': './coverage',
+  reporter: ['lcov', 'clover', 'json'],
+  extension: ['.js', '.cjs', '.mjs', '.ts', '.tsx', '.jsx'],
+  excludeAfterRemap: true
+}
+
+function readNycOptions(workingDirectory) {
+  const pkgFilename = join(workingDirectory, 'package.json')
+  const pkg = existsSync(pkgFilename)
+    ? JSON.parse(readFileSync(pkgFilename, 'utf8'))
+    : {}
+  const pkgNycOptions = pkg.nyc || {}
+
+  const nycrcFilename = join(workingDirectory, '.nycrc')
+  const nycrc = existsSync(nycrcFilename)
+    ? JSON.parse(readFileSync(nycrcFilename, 'utf8'))
+    : {}
+
+  const nycrcJsonFilename = join(workingDirectory, '.nycrc.json')
+  const nycrcJson = existsSync(nycrcJsonFilename)
+    ? JSON.parse(readFileSync(nycrcJsonFilename, 'utf8'))
+    : {}
+
+  const nycOptions = combineNycOptions({
+    pkgNycOptions,
+    nycrc,
+    nycrcJson,
+    defaultNycOptions
+  })
+  debug('combined NYC options %o', nycOptions)
+
+  return nycOptions
+}
+
 function checkAllPathsNotFound(nycFilename) {
   const nycCoverage = JSON.parse(readFileSync(nycFilename, 'utf8'))
 
@@ -198,5 +258,8 @@ module.exports = {
   showNycInfo,
   resolveRelativePaths,
   checkAllPathsNotFound,
-  tryFindingLocalFiles
+  tryFindingLocalFiles,
+  readNycOptions,
+  combineNycOptions,
+  defaultNycOptions
 }

task-utils.js

@@ -7,7 +7,8 @@ const {
   showNycInfo,
   resolveRelativePaths,
   checkAllPathsNotFound,
-  tryFindingLocalFiles
+  tryFindingLocalFiles,
+  readNycOptions
 } = require('./task-utils')
 const { fixSourcePaths } = require('./support-utils')
 const NYC = require('nyc')
@@ -28,7 +29,6 @@ const pkgFilename = join(processWorkingDirectory, 'package.json')
 const pkg = existsSync(pkgFilename)
   ? JSON.parse(readFileSync(pkgFilename, 'utf8'))
   : {}
-const nycOptions = pkg.nyc || {}
 const scripts = pkg.scripts || {}
 const DEFAULT_CUSTOM_COVERAGE_SCRIPT_NAME = 'coverage:report'
 const customNycReportScript = scripts[DEFAULT_CUSTOM_COVERAGE_SCRIPT_NAME]
@@ -42,6 +42,37 @@ function saveCoverage(coverage) {
   writeFileSync(nycFilename, JSON.stringify(coverage, null, 2))
 }
 
+function maybePrintFinalCoverageFiles(folder) {
+  const jsonReportFilename = join(folder, 'coverage-final.json')
+  if (!existsSync) {
+    debug('Did not find final coverage file %s', jsonReportFilename)
+    return
+  }
+
+  debug('Final coverage in %s', jsonReportFilename)
+  const finalCoverage = JSON.parse(readFileSync(jsonReportFilename, 'utf8'))
+  Object.keys(finalCoverage).forEach(key => {
+    const s = finalCoverage[key].s || {}
+    const statements = Object.keys(s)
+    const totalStatements = statements.length
+    let coveredStatements = 0
+    statements.forEach(statementKey => {
+      if (s[statementKey]) {
+        coveredStatements += 1
+      }
+    })
+
+    const allCovered = coveredStatements === totalStatements
+    debug(
+      '%s %s statements covered %d/%d',
+      allCovered ? '✅' : '⚠️',
+      key,
+      coveredStatements,
+      totalStatements
+    )
+  })
+}
+
 const tasks = {
   /**
    * Clears accumulated code coverage information.
@@ -122,41 +153,29 @@ const tasks = {
       })
     }
 
-    const reportFolder = nycOptions['report-dir'] || './coverage'
-    const reportDir = resolve(reportFolder)
-    const reporter = nycOptions['reporter'] || ['lcov', 'clover', 'json']
-
-    // TODO we could look at how NYC is parsing its CLI arguments
-    // I am mostly worried about additional NYC options that are stored in
-    // package.json and .nycrc resource files.
-    // for now let's just camel case all options
     // https://github.com/istanbuljs/nyc#common-configuration-options
-    const nycReportOptions = {
-      reportDir,
-      tempDir: coverageFolder,
-      reporter: [].concat(reporter), // make sure this is a list
-      include: nycOptions.include,
-      exclude: nycOptions.exclude,
-      // from working with TypeScript code seems we need these settings too
-      excludeAfterRemap: true,
-      extension: nycOptions.extension || [
-        '.js',
-        '.cjs',
-        '.mjs',
-        '.ts',
-        '.tsx',
-        '.jsx'
-      ],
-      all: nycOptions.all
+    const nycReportOptions = readNycOptions(processWorkingDirectory)
+
+    // override a couple of options
+    nycReportOptions.tempDir = coverageFolder
+    if (nycReportOptions['report-dir']) {
+      nycReportOptions['report-dir'] = resolve(nycReportOptions['report-dir'])
     }
 
     debug('calling NYC reporter with options %o', nycReportOptions)
     debug('current working directory is %s', process.cwd())
     const nyc = new NYC(nycReportOptions)
 
     const returnReportFolder = () => {
-      debug('after reporting, returning the report folder name %s', reportDir)
-      return reportDir
+      const reportFolder = nycReportOptions['report-dir']
+      debug(
+        'after reporting, returning the report folder name %s',
+        reportFolder
+      )
+
+      maybePrintFinalCoverageFiles(reportFolder)
+
+      return reportFolder
     }
     return nyc.report().then(returnReportFolder)
   }