add comments about (a)sync processing

Author: tsnobip

scripts/rescript_format.js

@@ -135,6 +135,9 @@ async function main(argv, rescript_exe, bsc_exe) {
       }
       files = output.stdout.split("\n").map(x => x.trim());
       var incorrectlyFormattedFiles = 0;
+      // it's ok that this processing is asynchronous
+      // given we only write one-liners during it
+      // so stdout should not get mixed (or can oneliners actually be mixed too?)
       try {
         const _promises = await Promise.all(
           files.map(async file => {
@@ -218,6 +221,7 @@ async function main(argv, rescript_exe, bsc_exe) {
       files.forEach(file => {
         var write = isSupportedFile(file) && !check.val;
         var flags = write ? ["-o", file, "-format", file] : ["-format", file];
+        // we make this processing synchronous in order not to mix stdout
         try {
           const formatted = child_process.execFileSync(bsc_exe, flags);
           if (!write) {