fix: file URL to system path conversion (#46)

This commit fixes the conversion from `file://` urls to system-dependent paths. It ensures that it works on Windows and with special characters.

lib/report.js

@@ -1,4 +1,5 @@
 const Exclude = require('test-exclude')
+const furi = require('furi')
 const libCoverage = require('istanbul-lib-coverage')
 const libReport = require('istanbul-lib-report')
 const reports = require('istanbul-reports')
@@ -74,7 +75,7 @@ class Report {
   _getMergedProcessCov () {
     const v8ProcessCovs = []
     for (const v8ProcessCov of this._loadReports()) {
-      v8ProcessCovs.push(this._filterProcessCov(v8ProcessCov))
+      v8ProcessCovs.push(this._normalizeProcessCov(v8ProcessCov))
     }
     return mergeProcessCovs(v8ProcessCovs)
   }
@@ -101,21 +102,26 @@ class Report {
   }
 
   /**
-   * Returns a filtered process coverage.
+   * Normalizes a process coverage.
+   *
+   * This function replaces file URLs (`url` property) by their corresponding
+   * system-dependent path and applies the current inclusion rules to filter out
+   * the excluded script coverages.
    *
    * The result is a copy of the input, with script coverages filtered based
    * on their `url` and the current inclusion rules.
    * There is no deep cloning.
    *
-   * @param v8ProcessCov V8 process coverage to filter.
-   * @return {v8ProcessCov} Filtered V8 process coverage.
+   * @param v8ProcessCov V8 process coverage to normalize.
+   * @return {v8ProcessCov} Normalized V8 process coverage.
    * @private
    */
-  _filterProcessCov (v8ProcessCov) {
+  _normalizeProcessCov (v8ProcessCov) {
     const result = []
     for (const v8ScriptCov of v8ProcessCov.result) {
-      // TODO: implement real fix from https://github.com/nodejs/node/issues/23783
-      v8ScriptCov.url = v8ScriptCov.url.replace(/^file:\/\//, '')
+      if (/^file:\/\//.test(v8ScriptCov.url)) {
+        v8ScriptCov.url = furi.toSysPath(v8ScriptCov.url)
+      }
       if (this.exclude.shouldInstrument(v8ScriptCov.url) &&
         (!this.omitRelative || isAbsolute(v8ScriptCov.url))) {
         result.push(v8ScriptCov)

package.json

@@ -35,6 +35,7 @@
     "@c88/v8-coverage": "^0.1.0",
     "find-up": "^3.0.0",
     "foreground-child": "^1.5.6",
+    "furi": "^1.0.0",
     "istanbul-lib-coverage": "^2.0.1",
     "istanbul-lib-report": "^2.0.1",
     "istanbul-reports": "^2.0.0",