Flow types erased for `fetch`. #29866

chrisbobbe · 2020-09-05T01:07:12Z

Description

In a fresh RN v0.63.2 project (the latest, as of writing), some lines in node_modules/react-native/interface.js suppress Flow type-checking for fetch by making it (and Headers, Request, and Response) any.

Like #22590, but the file has since been moved, in e54ecf9. Those lines first appeared in 7141948 (6fe3b2229 on the PR branch). I'm taking @ferrannp's invitation on #22590 to comment further saying the issue hasn't been fixed (though I'm blocked from posting on the same issue). Back then, as now, the issue is certainly not related to one's precise configuration (beyond using Flow instead of not using Flow), and running the repro should confirm that. 😉 Let me know if the repro fails, though.

React Native version:

$ react-native info
info Fetching system and libraries information...
System:
    OS: macOS 10.15.6
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 582.10 MB / 16.00 GB
    Shell: 3.2.57 - /bin/bash
  Binaries:
    Node: 12.12.0 - ~/.nvm/versions/node/v12.12.0/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 6.11.3 - ~/.nvm/versions/node/v12.12.0/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  Managers:
    CocoaPods: 1.9.3 - /Users/chrisbobbe/.gem/bin/pod
  SDKs:
    iOS SDK:
      Platforms: iOS 13.7, DriverKit 19.0, macOS 10.15, tvOS 13.4, watchOS 6.2
    Android SDK:
      API Levels: 23, 25, 26, 27, 28, 29
      Build Tools: 27.0.3, 28.0.3, 29.0.2
      System Images: android-28 | Google Play Intel x86 Atom
      Android NDK: Not Found
  IDEs:
    Android Studio: 3.6 AI-192.7142.36.36.6241897
    Xcode: 11.7/11E801a - /usr/bin/xcodebuild
  Languages:
    Java: 1.8.0_212-release - /usr/bin/javac
    Python: 2.7.16 - /usr/bin/python
  npmPackages:
    @react-native-community/cli: Not Found
    react: 16.13.1 => 16.13.1 
    react-native: 0.63.2 => 0.63.2 
  npmGlobalPackages:
    *react-native*: Not Found

Steps To Reproduce

To set up, make a new project with react-native init and run yarn add flow-bin@^0.122.0 (or whichever version is mentioned under [version] in .flowconfig.). Then insert, e.g., fetch('https://www.google.com') in some valid FILE at LINE and COLUMN (e.g., App.js at line 1, column 1)

Then, to see the problem:

Run yarn flow type-at-pos FILE LINE COLUMN (e.g., yarn flow type-at-pos App.js 1 1)

Expected Results

I expect this output:

(input: RequestInfo, init?: RequestOptions) => Promise<Response> (or whatever Flow's internal type definitions have for fetch at the Flow version appropriate for the RN version)

Instead, I get this output:

any (explicit)

If I remove the indicated lines in node_modules/react-native/interface.js and rerun steps 1 and 2 above, I get the expected output.

The text was updated successfully, but these errors were encountered:

safaiyeh · 2020-09-06T01:55:30Z

Hi @chrisbobbe thanks for the issue! It seems like you found a quick fix. Do you mind submitting a PR for this for review?

With facebook/react-native#29866, `fetch` and a few of the major things it uses are totally untyped. But react-native doesn't suppress `RequestOptions` [1], so we can still use that to help make sure we're passing around the right kinds of stuff that will eventually be fed to `fetch`. It looks like we've gestured toward not allowing `params` to contain `headers`, so, make that explicit. A type-cast and a $FlowFixMe on it at the top of `getFetchParams` can fall away naturally. [1] See it at https://www.saltycrane.com/cheat-sheets/flow-type/latest/

Fixes: facebook#29866

chrisbobbe · 2020-09-10T23:56:47Z

Hi @chrisbobbe thanks for the issue! It seems like you found a quick fix. Do you mind submitting a PR for this for review?

Sure thing! 🙂 Just sent #29926.

With facebook/react-native#29866, `fetch` and a few of the major things it uses are totally untyped. But react-native doesn't suppress `RequestOptions` [1], so we can still use that to help make sure we're passing around the right kinds of stuff that will eventually be fed to `fetch`. It looks like we've gestured toward not allowing `params` to contain `headers`, so, make that explicit. A type-cast and a $FlowFixMe on it at the top of `getFetchParams` can fall away naturally. [1] See it at https://www.saltycrane.com/cheat-sheets/flow-type/latest/

Fixes: facebook#29866

With facebook/react-native#29866, `fetch` and a few of the major things it uses are totally untyped. But react-native doesn't suppress `RequestOptions` [1], so we can still use that to help make sure we're passing around the right kinds of stuff that will eventually be fed to `fetch`. It looks like we've gestured toward not allowing `params` to contain `headers`, so, make that explicit. A type-cast and a $FlowFixMe on it at the top of `getFetchParams` can fall away naturally. [1] See it at https://www.saltycrane.com/cheat-sheets/flow-type/latest/

chrisbobbe · 2020-09-18T17:21:43Z

There's been a small issue with the CLA on my PR #29926 (Facebook has been unresponsive); @safaiyeh, do you mind taking a quick look if you have time? Maybe you've seen the issue before and have some advice on how to proceed? 🙂

Once this is out of the way, there will be a lower barrier for me to make more PRs. 🙂

With facebook/react-native#29866, `fetch` and a few of the major things it uses are totally untyped. But react-native doesn't suppress `RequestOptions` [1], so we can still use that to help make sure we're passing around the right kinds of stuff that will eventually be fed to `fetch`. Also, it looks like the functionality of `getFetchParams` would break if a caller included `headers`, so make the type not allow that. A type-cast and a $FlowFixMe on it at the top of `getFetchParams` can fall away naturally. [1] See it at https://www.saltycrane.com/cheat-sheets/flow-type/latest/

stale · 2020-12-25T14:16:39Z

Hey there, it looks like there has been no activity on this issue recently. Has the issue been fixed, or does it still require the community's attention? This issue may be closed if no further activity occurs. You may also label this issue as a "Discussion" or add it to the "Backlog" and I will leave it open. Thank you for your contributions.

chrisbobbe · 2020-12-25T17:50:45Z

Go away stale-bot, there's no sign this issue has been fixed. 🙂

chrisbobbe · 2021-02-08T17:46:38Z

It looks like this was resolved in 6651b7c. Thanks, @panagosg7!

Summary: The main change of this diff is in file react-native-github/interface.js. This file used to override the definitions for `fetch`, `Headers`, `Request`, `Response`, `requestAnimationFrame` of flow/lib/bom.js and type them as `any` instead. This is inconsistent with the rest of the flow library definitions that expect `Request`, for example, to be adequately typed. Overriding this defnition with `any` raises `[value-as-type]` errors in the library definitions themselves. Due to a Flow bug, these errors were silently suppressed, leading to loss of coverage. I'm trying to clean-up these errors and fix the Flow bug so that library errors are always surfaced. This diff also: * Removes 53 unused suppression comments * Adds 110 new error suppressions Changelog: [Internal] Reviewed By: pieterv Differential Revision: D25806504 fbshipit-source-id: e312bc5d64818b63c3b8b4f86dea51e13aacfac0

chrisbobbe added the Needs: Triage 🔍 label Sep 5, 2020

react-native-bot added Flow 🌐Networking Related to a networking API. labels Sep 5, 2020

safaiyeh added DX Issues concerning how the developer experience can be improved. and removed Needs: Triage 🔍 🌐Networking Related to a networking API. labels Sep 6, 2020

chrisbobbe added a commit to chrisbobbe/react-native that referenced this issue Sep 10, 2020

interface: Stop erasing Flow's internal fetch type and friends.

5d0c87c

Fixes: facebook#29866

chrisbobbe mentioned this issue Sep 10, 2020

interface: Stop erasing Flow's internal fetch type def and friends. #29926

Closed

chrisbobbe added a commit to chrisbobbe/react-native that referenced this issue Sep 15, 2020

interface: Stop erasing Flow's internal fetch type def and friends.

3e52e43

Fixes: facebook#29866

stale bot added the Stale There has been a lack of activity on this issue and it may be closed soon. label Dec 25, 2020

stale bot removed the Stale There has been a lack of activity on this issue and it may be closed soon. label Dec 25, 2020

chrisbobbe closed this as completed Feb 8, 2021

facebook locked as resolved and limited conversation to collaborators Feb 8, 2022

react-native-bot added the Resolution: Locked This issue was locked by the bot. label Feb 8, 2022

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Flow types erased for `fetch`. #29866

Flow types erased for `fetch`. #29866

chrisbobbe commented Sep 5, 2020 •

edited

Loading

safaiyeh commented Sep 6, 2020

chrisbobbe commented Sep 10, 2020

chrisbobbe commented Sep 18, 2020 •

edited

Loading

stale bot commented Dec 25, 2020

chrisbobbe commented Dec 25, 2020

chrisbobbe commented Feb 8, 2021

Flow types erased for fetch. #29866

Flow types erased for fetch. #29866

Comments

chrisbobbe commented Sep 5, 2020 • edited Loading

Description

React Native version:

Steps To Reproduce

Expected Results

safaiyeh commented Sep 6, 2020

chrisbobbe commented Sep 10, 2020

chrisbobbe commented Sep 18, 2020 • edited Loading

stale bot commented Dec 25, 2020

chrisbobbe commented Dec 25, 2020

chrisbobbe commented Feb 8, 2021

Flow types erased for `fetch`. #29866

Flow types erased for `fetch`. #29866

chrisbobbe commented Sep 5, 2020 •

edited

Loading

chrisbobbe commented Sep 18, 2020 •

edited

Loading