Watching broken in TypeScript 4.1.2 and newer (including latest version 5.x+)

[benmccann]

Overview

This regression is almost certainly caused by #352. That's the only real commit in 4.1.2 and things work with 4.1.1. Furthermore that puts createWatchProgram in an if statement.

This issue has been reported by a few different users of the Sapper web framework (also created by Rich Harris) over the past few days sveltejs/sapper#1293

Environment

• Rollup Plugin Name: @rollup/plugin-typescript
• Rollup Plugin Version: 4.1.2
• Rollup Version: 2.18.0
• Operating System (or Browser): Ubuntu
• Node Version: v12.16.3

How Do We Reproduce?

Reproduction repo

Steps:

1. Clone and install
2. Run npm run dev
3. Make a GET request, such as by visiting in the browser, /fails and see the result 1
4. Modify src/routes/fails.ts and change 1 to 2. The change will be picked up and "rebuild"
5. Do 3 again but still see 1 instead of the new 2

Expected Behavior

The page should change

Actual Behavior

The page doesn't change

[babichjacob]

Also can reproduce on

• Rollup Plugin Name: @rollup/plugin-typescript
• Rollup Plugin Version: 5.0.1
• Rollup Version: 2.18.1
• System (or Browser): macOS 10.15.5
• Node v14.4.0

#425 was released with 5.0.0 and supposed to fix this (and #418), but it would appear not.
It's possible that when #449 is completed and merged that this will be solved (?)

[shellscape]

Fwiw we don't typically triage plugin issues on versions that are a full major behind

We're happy to review PRs that address the issue.

[benmccann]

This is also broken in the latest release

[dionysiusmarquis]

@benmccann a quick fix could be to add process.env.ROLLUP_WATCH = true right before the rollup.watch inside the sapper RollupCompiler watch hook. But it might be better to wait for the PR

[benmccann]

Here's the PR that will fix this: #449