fix: use fs sync method to write files

In certain cases the stats are not written, this seems to be because the process is being terminated before it finish to write. The reason being is using a sync version of tap.

To get around this, the sync method of fs should be used to allow the creation of files.

Related to: angular/angular-cli#12763

Author: Alan Agius

index.js

@@ -140,14 +140,12 @@ module.exports = class SpeedMeasurePlugin {
       chalk.enabled = true;
       if (outputToFile) {
         const writeMethod = fs.existsSync(this.options.outputTarget)
-          ? fs.appendFile
-          : fs.writeFile;
-        writeMethod(this.options.outputTarget, output + "\n", err => {
-          if (err) throw err;
-          console.log(
-            smpTag() + "Outputted timing info to " + this.options.outputTarget
-          );
-        });
+          ? fs.appendFileSync
+          : fs.writeFileSync;
+        writeMethod(this.options.outputTarget, output + "\n");
+        console.log(
+          smpTag() + "Outputted timing info to " + this.options.outputTarget
+        );
       } else {
         const outputFunc = this.options.outputTarget || console.log;
         outputFunc(output);