Duplicate error message (esp. when pretty: true)

[kitsonk]

What happens and why it is wrong

Duplicate semantic errors get logged to the console, which causes confusion. For example:

./node_modules/rollup/bin/rollup -c ../../rollup.config.js -i ../../js/main.ts -o gen/bundle/main.js --silent
[!] (rpt2 plugin) Error: ../../js/main.ts:8:1 - error TS2304: Cannot find name 'confounded'.

8 confounded;
  ~~~~~~~~~~

../../js/main.ts
Error: ../../js/main.ts:8:1 - error TS2304: Cannot find name 'confounded'.

8 confounded;
  ~~~~~~~~~~

    at error (/Users/kkelly/github/deno/third_party/node_modules/rollup/dist/rollup.js:3365:15)
    at Object.error (/Users/kkelly/github/deno/third_party/node_modules/rollup/dist/rollup.js:20727:13)
    at RollupContext.error (/Users/kkelly/github/deno/third_party/node_modules/rollup-plugin-typescript2/src/rollupcontext.ts:36:18)
    at lodash_2 (/Users/kkelly/github/deno/third_party/node_modules/rollup-plugin-typescript2/src/print-diagnostics.ts:37:10)
    at arrayEach (/Users/kkelly/github/deno/third_party/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:516:11)
    at forEach (/Users/kkelly/github/deno/third_party/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:9342:14)
    at printDiagnostics (/Users/kkelly/github/deno/third_party/node_modules/rollup-plugin-typescript2/src/print-diagnostics.ts:9:2)
    at Object.transform (/Users/kkelly/github/deno/third_party/node_modules/rollup-plugin-typescript2/src/index.ts:238:5)
    at /Users/kkelly/github/deno/third_party/node_modules/rollup/dist/rollup.js:20750:41
    at process._tickCallback (internal/process/next_tick.js:68:7)

I am not entirely sure how much this is rollup-plugin-typescript2 and how much of this is just the way rollup behaves, but I couldn't find an answer either way.

Versions

• typescript: 3.0.1
• rollup: 0.63.2
• rollup-plugin-typescript2: 0.16.1

[vineetit1991]

any input on this ? I am also facing this issue

[ezolenko]

I don't get it with just any error, could you create a test repo with reproduction?

Might depend on error type (typescript only, or something that would trip rollup itself) execution mode (clean build / rebuild / watch) and rollup/plugin settings.

This is what I usually get:
(3 there were errors or warnings lines for 3 bundles that are generated in that build)

rpt2: there were errors or warnings.
rpt2: rolling caches
rpt2: there were errors or warnings.
rpt2: rolling caches
rpt2: there were errors or warnings.
rpt2: rolling caches
(!) Plugin rpt2: src/index.ts:316:18 - error TS2304: Cannot find name 'Plugin5Context'.

316     _onwrite(this: Plugin5Context, _output: OutputOptions): void
                       ~~~~~~~~~~~~~~

src\index.ts

[agilgur5]

Going to close this out as a reproduction was unsuccessful and this issue has not received any activity in a few years (and may not be relevant in newer versions anymore).

Can re-open later if warranted on current versions and with a repro.

[agilgur5]

So I ended up reproducing this issue while testing #372 .

Per #372 (comment), the last error will indeed get printed out twice in all cases. It just happens to be a lot more visible when using tsconfig's pretty option. That is what OP was using and is what #372 makes the default.

Per #372 (comment), this duplication actually happens within Rollup though, and not because of this plugin. Rollup prints out the error message, and then also prints the error stack, which can actually contain the error message in it, causing duplication.

This may depend on runtime though as Error.stack is non-standardized. It may also depend on how one uses Rollup as well, since this code is in the Rollup CLI specifically.

I'll have a PR out here to workaround this in rpt2 shortly. Will also have to make a similar PR to Rollup itself to handle this upstream. The PR here will be written to be forward-compatible with newer versions of Rollup if that gets merged upstream as well.

[agilgur5]

rollup/plugins#376 shows and mentions a "duplicated code frame" for @rollup/plugin-babel as well, so this seems to be a long-standing issue that has never quite been fixed.
I couldn't find references to this in Rollup proper, in other issues in rollup/plugins, or elsewhere here, so I guess this hasn't been noticed that often, and seemingly only noticed by people looking to get "prettified" output (either in TS or in Babel).

[agilgur5]

#373 works around this Rollup bug and has been released in 0.33.0

[agilgur5]

This has been fixed upstream in Rollup in rollup/rollup#4749 and released in Rollup v3.7.5