Replace system lambda #601
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This is a code example in tests of replacing the "system-lambda" library specific to our needs of checking program output to the terminal/console. The `ContextForTerminal` test class is reusable, but unclear we should provide this even as copy/paste for folks browsing our test code. Along the way: - Find that the PMD rule on "CommentSize" is awful. We should suppress it by default. When you write large comments (for example, in Javadoc) your build should not break. - Suppressions of PMD checks, or rewriting for Checkstyle. This is a smell that either code is wonky, or this is too low-level to make a good example. - Reminder that the old Java APIs only dealt with UTF issues in a half-ass fashion. A reason to use libraries that dealt with this for you. - Reminder that terminal/console out/err is not thread-safe, and no library can fix that.
This is a code example in tests of replacing the "system-lambda" library specific to our needs of checking program output to the terminal/console. The `ContextForTerminal` test class is reusable, but unclear we should provide this even as copy/paste for folks browsing our test code. Along the way: - Find that the PMD rule on "CommentSize" is awful. We should suppress it by default. When you write large comments (for example, in Javadoc) your build should not break. - Suppressions of PMD checks, or rewriting for Checkstyle. This is a smell that either code is wonky, or this is too low-level to make a good example. - Reminder that the old Java APIs only dealt with UTF issues in a half-ass fashion. A reason to use libraries that dealt with this for you. - Reminder that terminal/console out/err is not thread-safe, and no library can fix that.
IntelliJ is happier with the line breaks in this commit. Also, update the javadocs with better links and wording.
5 tasks
Making things public helps with Javadoc generation.
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Howdy!
I'm looking to replace the
system-lambdatest library with small, local, bespoke code. This library specializes in nicer Java code for messing withSystemglobals in the JVM such as STDOUT/STDERR, et al.This addresses #483. Currently the build on this branch is green.
To consider before approving:
Should the project provide example replacement code rather than continuing to use a 3rd-party library?
Use a code style that:
system-lambdawith improved naming:captureTerminal(this code) vstapSystemOutNormalized(system-lambda library) (Expected discussion on naming for "captureTerminal" -- all TWers love noodling on naming 😀)TerminalContextand only the static method ofcaptureTerminalshould be visible. Do not look behind the curtain: we mess with JDK global statics)@Bukharovsi GitHub auto-suggested you to review.
:DWe won't depend on your feedback to decide if to merge this PR--there is a lot on your plate right now--, but would love your thoughts!I really like the https://github.com/stefanbirkner/system-lambda library, and use it in some side projects where I need to test complicated things about the terminal or environment. For the example code in this project, it feels like using a cannon to hit an orange.
Footnotes
system-lambdadoes is to wrap a continuation (the call to test). Describing it this way is unhelpful for most programmers. We are wrapping calls (Application.main) that access monads for STDOUT and STDERR (such a scholarly description meaning "side effect"), and capturing the data sent to them so we can test these interactions.Yep, this is what testing "Hello, world" looks like! No way I want to talk about it this way to the general programmer audience.