[FR]: Demonstrate new tsgo

[alexeagle]

What is the current behavior?

type-checks are slow

Describe the feature

The TypeScript team has ported the compiler/type-checker to Go which makes it a lot faster:

https://devblogs.microsoft.com/typescript/typescript-native-port/

Show how to try this out with Bazel.

[alexeagle]

See some WIP to attempt this: https://github.com/aspect-build/rules_ts/compare/tsgo2

Failing because the --rootDir flag isn't defined yet on tsgo

[jfirebaugh]

FYI, --rootDir is now supported by tsgo. I've been using it successfully via

directory_path(
    name = "tsgo_entrypoint",
    directory = ":node_modules/@typescript/native-preview/dir",
    path = "bin/tsgo.js",
    visibility = ["//visibility:public"],
)

js_binary(
    name = "tsgo",
    data = [":node_modules/@typescript/native-preview"],
    entry_point = ":tsgo_entrypoint",
    visibility = ["//visibility:public"],
)

[jfirebaugh]

The biggest issue with tsgo + Bazel currently is that patch_node_fs isn't effective for tsgo, so it escapes the sandbox, which triggers microsoft/typescript-go#1080. --experimental_use_hermetic_linux_sandbox can be used to solve this on linux, but I don't know of a good solution for macOS.

[alexeagle]

I have picked this up again. Unorganized thoughts:

• No longer need to build the Go binary ourselves thanks to the native npm packages, e.g. https://app.unpkg.com/@typescript/native-preview-darwin-arm64@7.0.0-dev.20251117.1/files/lib
• It would be interesting to build into a WASM binary to allow cross-platform cache hits, e.g. type-check cache hit on MacOS dev machine from a linux remote cache
• I'd like to experiment with type-check tsgo as a validation action produced by an aspect that visits the ts_project graph, using purely OXC as the emit for both JS and DTS (implies isolatedDeclarations)
• Reproduced @jfirebaugh issue trivially, as outputs aren't written to the location Bazel expects