fix: Handle backslashes in coverage file path (#356)

Co-authored-by: Gleb Bahmutov <[email protected]>

Author: taki9

task-utils.js

@@ -343,7 +343,9 @@ function includeAllFiles(nycFilename, nycOptions) {
 
   const nycCoverage = JSON.parse(readFileSync(nycFilename, 'utf8'))
   const coverageKeys = Object.keys(nycCoverage)
-  const coveredPaths = coverageKeys.map((key) => nycCoverage[key].path)
+  const coveredPaths = coverageKeys.map(key =>
+    nycCoverage[key].path.replace(/\\/g, '/')
+  )
 
   debug('coverage has %d record(s)', coveredPaths.length)
   // report on first couple of entries