Types are only made available when explicitly added in tsconfig.json

[paullewis]

Hey,

Was just trying the 0.11.0 prerelease, and thought I'd let you know of an unusual behavior (in case you don't know!).

Supposing you have a BUILD.bazel file like this:

load("@aspect_rules_ts//ts:defs.bzl", "ts_project")

ts_project(
    name = "src",
    srcs = [
        "src.ts",
    ],
    declaration = True,
    tsconfig = "//:tsconfig",
    deps = [
        "//:node_modules/@types/node",
    ],
)

ts_project(
    name = "src_test",
    testonly = True,
    srcs = ["src.test.ts"],
    declaration = True,
    tsconfig = "//:tsconfig",
    deps = [
        ":src",
        "//:node_modules/@types/node",
    ],
)

It doesn't really matter what you have in src.ts, but supposing the following is in src.test.ts:

import assert from 'assert';

console.log(assert);

You'll get the following error when trying to build :src_test:

src.test.ts(1,20): error TS2307: Cannot find module 'assert' or its corresponding type declarations.

It seems the double dep of "//:node_modules/@types/node" in both :src and :src_test is the root of the issue, though I'm not at all sure why. Removing @types/node from :src will prevent the error from emitting, but that doesn't seem like the right fix!

[paullewis]

For clarity, @types/node is where the assert module is declared.

[paullewis]

Just a heads up that this is present in rules_ts-1.0.0-rc0 (and rules_js-1.0.0 since that's how the node deps are presented).

[paullewis]

Okay, I dug a little further and what I thought was the issue ... wasn't.

I've made a repo here: https://github.com/paullewis/repro-rules-ts-issue-111

According to the TS docs any @types dir in node_modules should be picked up. When looking at the repro repo in VSCode I see that the types for assert are fine, and I can Cmd + click to get to the node types. When I try a Bazel build it can't find the types, even though they are presented as a dep (//:node_modules/@types/node).

If, however, I explicitly add "types": ["node"] to the tsconfig.json (in the repro it's already there for uncommenting) then the build passes.

All very confusing to me, really. Setting the types in the tsconfig.json to ["node"] should, as I understand it, make tsc go and look in @types/node... but when it's not set it should still find @types/node anyway given they're presented as a dep.

[paullewis]

I sorted a temporary workaround: set supports_workers = False in the ts_project rule.

[thesayyn]

@paullewis could you try with https://github.com/aspect-build/rules_ts/releases/tag/v1.0.0-rc1 and see if the issue persists?

[paullewis]

Yes, that seems to fix it - thank you! I'll close the Issue. Out of interest, what was the cause?

[gregmagolan]

The worker mode virtual file system @thesayyn wrote wasn't following the node_modules/@types symlink to check if it was pointing to a directory. When typescript asked for the contents of node_modules/@types it got back an empty list.

[gregmagolan]

Was fixed by #125

[paullewis]

I see - thanks for the info!