Packager build error on Windows: "Unexpected identifier" or "Unable to resolve a Haste module"

[gengjiawen]

I first discover this issue in June 16 (react/metro#181), which is a month ago, but got less attention on this in beggining. Then react native 0.56 released, which totally expose the problem, which bothering windows user even for now (see #20346 and react/metro#200).

Here is what I want to have been achieve

Fix debug RNTester on windows (merged in 2018-08-04)

Related pr: #19974.
The main purpose is refactor bash script to nodejs script, so it can be cross platform. I remove some types on file simplily because they not flow-typed file. @pvdz Please merge this asap. For without it, debugging RNTester will be an unusable on windows

Fix RNTester in release mode on windows (merged on 18/07/31)

Related pr: #20293.
This is a windows specific bug. And this bothered me very long time , I searched really really a lot to fix it.
Without it you will have build problem like this:

* What went wrong:
Failed to capture snapshot of input files for task ':RNTester:android:app:bundleReleaseJsAndAssets' property '$1' during up-to-date check.
> Failed to create MD5 hash for file content.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

I think it's clean fix and I have appveyor log to prove my fix work, you can see detail in that pr. So I hope @hramos or anyone with merge permission can review my pr.

Fix general problem like

Problem like SyntaxError: Unexpected identifier or 'Unable to resolve a haste module' or 'Unable to resolve a module' has been fixed in master branch by the help of metro team. But when I communicate with @kelset , branch 0.57 still not working. But I believe we can fix that soon.

And Many developers works on windows instead of macOS. And this has been take too long to fix. And there are many windows developer still suffer from this issue in today.

In the end, I love react native. But dear react native official members, don't make us wait too long.

[react-native-bot]

We are automatically closing this issue because it does not appear to follow any of the provided issue templates.

Please make use of the bug report template to let us know about a reproducible bug or regression in the core React Native library.

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[hramos]

Reopening with "For Discussion" label. For future reference, if you use the provided "For Discussion" template, this would be done automatically by the bot.

[gengjiawen]

@hramos Can you review this pr #20293.

[kelset]

👋 Jiawen, thanks for the writeup!
Sadly as I mentioned my powers over reviewing and merging are limited.

Can I ask you a side question? You say

Problem like SyntaxError: Unexpected identifier or 'Unable to resolve a haste module' or 'Unable to resolve a module' has been fixed in master branch [..] but [..] , branch 0.57 still not working

Do you see any commit present in the master branch that is not on the 0.57 one?

cc @grabbou any idea of why it may work on one and not the other?

[gengjiawen]

@kelset The master branch when I tested works not metro 0.42.2, I will test the latest master branch again.

[gengjiawen]

The lastest master branch is broken again.

import type {CommandT} from './commands';
       ^^^^

SyntaxError: Unexpected identifier
    at new Script (vm.js:74:7)
    at createScript (vm.js:246:10)
    at Object.runInThisContext (vm.js:298:10)
    at Module._compile (internal/modules/cjs/loader.js:657:28)
    at Module._compile (D:\Developer\react-native\node_modules\pirates\lib\index.js:83:24)
    at Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Object.newLoader [as .js] (D:\Developer\react-native\node_modules\pirates\lib\index.js:88:7)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[kelset]

cc @rafeca