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ajalt / clikt

Multiplatform command line interface parsing for Kotlin
https://ajalt.github.io/clikt/
Apache License 2.0
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`CliktCommandTestResult.stdout` explands tabs to spaces #452

Closed sschuberth closed 1 year ago

sschuberth commented 1 year ago

What I'm seeing is that CliktCommandTestResult.stdout capturing terminal.println("\t") results in spaces instead of a tab character being returned. Now, I guess the issue could be anywhere from Mordant's terminal printing to Clikt's stdout caturing...

ajalt commented 1 year ago

Mordant has to expand tabs to be able to lay out widgets properly. e.g. if a table cell contains \t, it needs to know the width of that cell in order to draw table borders that line up. The only solution is to expand the tab. You can control the number of spaces used with the tabWidth parameter to the Terminal constructor.

sschuberth commented 1 year ago

Well, if you know via the tabWidth value how many spaces a tab should evaluate to, you could calculate the width without actually expanding tabs, or?

Anyway, is this documented somewhere, like in a migration guide from regular System.out.print to Mordant? Because in my case I had to (trivially) adjust several tests that were very strict about asserting CliktCommandTestResult.stdout to contain literal tab chars.

ajalt commented 1 year ago

could calculate the width without actually expanding tabs

No, because we don't know how wide a tab actually is. The actual tab width is set in whatever console/editor you're looking at the text. If we didn't expand tabs, the layouts would be messed up for anyone who uses a different tab width than you.

I agree that the tab expansion should be called out more prominently in the docs.