check if extra files are covered

Author: bahmutov

Diff for: .circleci/config.yml

@@ -195,10 +195,11 @@ workflows:
                 command: npx nyc report --check-coverage true --lines 100 --include unit-utils.js
                 working_directory: examples/same-folder
             - run:
-                command: node ../../scripts/check-coverage main.js
-                working_directory: examples/same-folder
-            - run:
-                command: node ../../scripts/check-coverage unit-utils.js
+                name: Check code coverage 📈
+                command: |
+                  node ../../scripts/check-coverage main.js
+                  node ../../scripts/check-coverage unit-utils.js
+                  node ../../scripts/only-covered main.js unit-utils.js
                 working_directory: examples/same-folder
 
       - publish:

Diff for: scripts/only-covered.js

@@ -0,0 +1,49 @@
+const { join } = require('path')
+const _ = require('lodash')
+
+const filenames = process.argv.slice(2)
+if (!filenames.length) {
+  console.error('Usage: node %s <file name 1> <file name 2>', __filename)
+  process.exit(1)
+}
+
+const shouldBeCovered = filepath =>
+  filenames.some(name => filepath.endsWith(name))
+
+const coverageFilename = join(process.cwd(), '.nyc_output', 'out.json')
+const coverage = require(coverageFilename)
+
+const coveredFilepaths = Object.keys(coverage).map(name => coverage[name].path)
+
+// console.log(coveredFilepaths)
+
+const [covered, extraCoveredFiles] = _.partition(
+  coveredFilepaths,
+  shouldBeCovered
+)
+
+if (extraCoveredFiles.length) {
+  console.error('Error: found extra covered files 🔥')
+  console.error('Expected the following files in coverage results')
+  console.error(filenames.join('\n'))
+  console.error('extra files covered 🔥')
+  console.error(extraCoveredFiles.join('\n'))
+  process.exit(1)
+}
+
+if (covered.length < filenames.length) {
+  console.error('Error: expected all files from the list to be covered 🔥')
+  console.error('Expected the following files in coverage results')
+  console.error(filenames.join('\n'))
+  console.error('But found only these files to be covered')
+  console.error(covered.join('\n'))
+
+  console.error('Files missing from the coverage 🔥')
+  const missingFiles = filenames.filter(
+    filename =>
+      !covered.some(coveredFilename => coveredFilename.endsWith(filename))
+  )
+  console.error(missingFiles.join('\n'))
+
+  process.exit(1)
+}