[epic] enable Rust compiler for OSS

[kassens]

This issue collects what I think is missing to update the Relay compiler to the Rust version in OSS. If someone want's to give any of this a shot, please comment here!

• Typescript generator as something configured in the compiler config.json
• Non-watchman file source. Currently we convert the directories in config.json into a watchman query for watch mode and simple builds. This was designed with non-watchman in mind and it should be possible to build out something that uses a different file-crawler and maybe file watcher crate. This is not strictly required, but I think removing this external required dependency would be nice. (Details in [rust] add non-Watchman file source #3193)
• Figure out how we deploy a pre-build binary using npm. The flow-bin package might be a good inspiration as that somehow loads the binary for that version on first use. (Details/discussion in [rust] figure out how to deploy pre-built binary to npm #3194)
• Some missing config options in how types are generated (Details/discussion in [rust] missing flow typegen config options #3195)
• Refine Typescript generation (Details/discussion in [rust] refine typescript type generation #3196)
• Rust compiler: purging non-Relay files from __generated__ folders #3438
• Rust compiler: definition of 'XYZQuery' appears to have changed #3437
• Look at assumptions of using hg
• Figure out situation with required variables with default values (see: [fix] experimental compiler: allow default args on required fields #3612 )
• Documentation/Blog Post about the release of new version of the compiler
• Deprecate JS version of the compiler
• [Rust][Compiler] Add Configuration/Document Query Persisting in the OSS Compiler #3627
• Fix issues listed here: https://github.com/vincentriemer/new-relay-compiler-issues-repro

[kassens]

@MaartenStaa made a huge leap start on this with #3182!

I understand there's a few improvements we can make to the types still by copying more what the JS OSS typescript generator produces: https://github.com/relay-tools/relay-compiler-language-typescript/blob/e1b092f081d4e816ecd17fb0d3b4e62cdf3db917/test/__snapshots__/TypeScriptGenerator-test.ts.snap

I'll file separate issues for the remaining checkboxes.

[kassens]

A good intro way to contribute is #3199 to convert the runtime unit tests to use artifacts generated by the Rust compiler. More details in there.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[alunyov]

Thanks stale-bot. I think we still need the issue. I'm looking at converting the rest of the tests. It may take a while, but we'll see.

[alunyov]

Non-watchman file source. Currently we convert the directories in config.json into a watchman query for watch mode and simple builds. This was designed with non-watchman in mind and it should be possible to build out something that uses a different file-crawler and maybe file watcher crate. This is not strictly required, but I think removing this external required dependency would be nice. (Details in #3193)

One more point on why we may need to work on this: the current watchman client for rust doesn't work on Windows (I was testing it with github actions for windows: https://github.com/alunyov/relay/runs/2104656440?check_suite_focus=true). So we may add something like: https://github.com/notify-rs/notify in OSS.

[kassens]

Baby steps, the example project todo app now compiles with the rust based compiler:

relayjs/relay-examples@470c497

NOTE: this is currently linux + mac only and requires watchman. Windows support is definitely a hard blocker for us, this is just an early preview to see where the problems are.

[maraisr]

Can we also look at supporting "watch-mode" for OSS?

Currently we're forced to use hg??

relay/compiler/crates/relay-compiler/src/file_source/watchman_file_source.rs

Line 391 in aeac451

.expect("Expect `hg` command getting base revision.");

[TrySound]

Will rust compiler support es modules? Looks like it was not implemented. Would be good to have it from the beginning to avoid shipping separate features without support like happened with refetchables.
https://github.com/facebook/relay/blob/main/compiler/crates/relay-codegen/src/js_module_format.rs

[maraisr]

@TrySound do you actually know where that js_module is actually used? Afaik it makes no difference? Or perhaps just with the langauge: "typescript" it isnt. I get import { ConcreteRequest } from 'relay-runtime'; in my __genearted__.

Or is that more about JSDepedency aka @module?

[alunyov]

Can we also look at supporting "watch-mode" for OSS?

Currently we're forced to use hg??

relay/compiler/crates/relay-compiler/src/file_source/watchman_file_source.rs

Line 391 in aeac451

.expect("Expect `hg` command getting base revision.");

Oh, yes, this is something that we need to fix. hg is definitely not a requirement for a watch mode.

[Brooooooklyn]

Friendly tips: If you have plans to expose Rust API to Node.js, you can take a look at napi-rs. For the pre-compile & testing & publish workflow, here is a demo: https://github.com/Brooooooklyn/snappy/releases/tag/v7.0.3

[mrtnzlml]

Hi, I would like to propose to include the following issues/bugs into the list as well:

• Rust compiler: purging non-Relay files from __generated__ folders #3438
• Rust compiler: definition of 'XYZQuery' appears to have changed #3437

Thanks! 😎

[alunyov]

hg issue fixed here: d336460

[huv1k]

There is a problem with @argumentDefinitions and defaultValue for @refetchable connections. Error is bellow:

    3 │       @argumentDefinitions(
    4 │         first: { type: "Int!", defaultValue: 2 }
      │                                              ^
    5 │         after: { type: "String" }

[ERROR] ✖︎ Non-nullable variable 'first' has a default value.

Query:

      fragment noteOwnerUsers on Query
      @argumentDefinitions(first: { type: "Int!" }, after: { type: "String" })
      @refetchable(queryName: "noteOwnersUsersConnection") {
        users(first: $first, after: $after)
          @connection(key: "noteOwnersUsersConnection_users") {
          edges {
            node {
              id
              email
            }
          }
        }
      }

[zth]

@huv1k this is actually a proper validation that has started working with the new compiler. So, the solution is to go ahead and remove the default value, or make the argument optional by removing the ! from the definition.

[alunyov]

v13 released. Closing this in favor of #3749