Don't give up when unable to extract some files (#244)

* Don't give up when unable to extract some files

Add try/catch block around file extraction so that the rest of the files are extracted if there is an issue with only a subset of the files in the archive.

* Fix unmatched curly brace

Added a closing curly brace because I'd missed one out

* removed a semicolon that was upsetting the linter

* Throw AggregateError if file couldn't be extracted

Collect file extraction errors and throw AggregateError after every file extraction has been attempted

* Removed logging & fixed extractionErrors handling 

...as suggested by Samuel Attard

* Remove dependancy on AggregateError

lib/asar.js

@@ -180,6 +180,7 @@ module.exports.extractAll = function (archive, dest) {
   // create destination directory
   fs.mkdirpSync(dest)
 
+  const extractionErrors = []
   for (const fullPath of filenames) {
     // Remove leading slash
     const filename = fullPath.substr(1)
@@ -200,14 +201,23 @@ module.exports.extractAll = function (archive, dest) {
       const linkTo = path.join(relativePath, path.basename(file.link))
       fs.symlinkSync(linkTo, destFilename)
     } else {
-      // it's a file, extract it
-      const content = disk.readFileSync(filesystem, filename, file)
-      fs.writeFileSync(destFilename, content)
-      if (file.executable) {
-        fs.chmodSync(destFilename, '755')
+      // it's a file, try to extract it
+      try {
+        const content = disk.readFileSync(filesystem, filename, file)
+        fs.writeFileSync(destFilename, content)
+        if (file.executable) {
+          fs.chmodSync(destFilename, '755')
+        }
+      } catch (e) {
+        extractionErrors.push(e)
       }
     }
   }
+  if (extractionErrors.length) {
+    throw new Error(
+      'Unable to extract some files:\n\n' +
+      extractionErrors.map(error => error.stack).join('\n\n'))
+  }
 }
 
 module.exports.uncache = function (archive) {