typedoc is writing 1 byte to STDERR when successful, causing other tools to raise flags

[kaiyoma]

Expected Behavior

typedoc should not be writing anything to STDERR if it was successful.

Actual Behavior

typedoc writes a single byte (a newline, I think) to STDERR on success. This is problematic because other tools (like Rush.js, for instance, which I'm using) interpret STDERR content to mean that something failed. When I run typedoc through Rush, I get messages like this:

==[ SUCCESS WITH WARNINGS: 1 project ]=========================================

--[ WARNING: babel-plugin-generate-i18n-id ]----------------[ 10.85 seconds ]--

Projects succeeded with warnings.

Steps to reproduce the bug

You can see here pretty clearly that there's one byte of content in STDERR, even though the build was successful:

$ yarn typedoc > typedoc.stdout 2> typedoc.stderr

$ ls -l typedoc.std*
-rw-r--r-- 1 Kyle Getz 197121   1 Apr  9 11:09 typedoc.stderr
-rw-r--r-- 1 Kyle Getz 197121 234 Apr  9 11:09 typedoc.stdout

$ cat typedoc.stdout
yarn run v1.22.5
$ C:\Work\web-components\packages\babel-plugin-generate-i18n-id\node_modules\.bin\typedoc
Info: Documentation generated at C:\Work\web-components\packages\babel-plugin-generate-i18n-id\docs
Done in 10.96s.

(I tested this same sequence of commands with a non-typedoc tool and the STDERR file was 0 bytes, as expected.)

Environment

• Typedoc version: 0.20.32
• TypeScript version: 4.2.3
• Node.js version: 14.15.0
• OS: Windows 10

[Gerrit0]

This is a weird one... and one I can't seem to reproduce. The only log statements in typedoc are in the bin file, and the ConsoleLogger. The ConsoleLogger always writes to stdout, since that's what TS does, and there are only 5 logs in the bin folder, 2 of which write to stderr... and that will only happen if there is an uncaught exception.

typedoc/bin/typedoc

Lines 29 to 30 in 2103f34

	console.error("TypeDoc exiting with unexpected error:");
	console.error(error);

typedoc/src/lib/utils/loggers.ts

Line 206 in 00ae3c7

ts.sys.write(output + ts.sys.newLine);

If you could set up a project that I could install that repros this issue, that would be great. My local test project doesn't seem to have this issue.

[kaiyoma]

Here's a pretty small repro: typedoc-repro.zip

After you unzip, run these commands from the root:

rush install
cd packages/foo/
yarn typedoc > typedoc.stdout 2> typedoc.stderr
ls -l typedoc.std*

And you'll see the one byte coming from STDERR.

[Gerrit0]

So... turns out this isn't in TypeDoc. It's in the progress module, that we use for a progress bar... and it only shows up if you redirect stdout!

I think you win for the weirdest bug I've fixed this year so far...

[kaiyoma]

Lol excellent. 😄 Glad you were able to track it down! Weird indeed.