Add testDocumentationExample

[ZacSweers]

So a neat feature @tnorbye told me about recently is that adding a test with the name testDocumentationExample will automatically index as a sample error on the lint docs site (which index our lints!)

This is a little test of that to see if it shows up here:

• https://googlesamples.github.io/android-custom-lint-rules/checks/ComposeNamingLowercase.md.html
• https://googlesamples.github.io/android-custom-lint-rules/checks/ComposeNamingUppercase.md.html

[tnorbye]

(FYI, that site doesn't get updated automatically, I do manual pushes every now and then. Yeah I probably should automate it. Here's the issue documentation generator by the way: https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/cli/src/main/java/com/android/tools/lint/LintIssueDocGenerator.kt )

[tnorbye]

...basically, I try to have every lint check have a test which is just a "good example" of an error -- instead of (as I initially did) mixing a bunch of corner cases all into the same test.

[ZacSweers]

Nice

[tnorbye]

The bottom of your screenshot shows that it actually just picked the first unit test it could find. That's probably because it was from the last time I had run the docs generation -- before your change.

I just updated the doc snapshot yesterday -- it now has the latest released version of the slack lint checks (91 issues included). And now it's picking up the default too -- it's no longer talking about having picked the first test etc:[

P.S. As I was looking I noticed that in some places there is no space between a previous sentence and the next one. I thought maybe there was an error in the formatting somewhere -- but I actually see it in the text messages in your unit tests too: https://github.com/slackhq/compose-lints/blob/main/compose-lint-checks/src/test/java/slack/lint/compose/ComposableFunctionNamingDetectorTest.kt -- look for "letter.They". I think what's going on is that you're passing in the explanation text as the error message (that's not usually recommended for reasons explained here: https://googlesamples.github.io/android-custom-lint-rules/api-guide.md.html#errormessageconventions/includedetails -- and your issue explanation seems to not put a space before the line continuation () characters. Maybe lint is using a different convention than other tools? But lint treats this kind of like string concatenations, e.g.

foo \
bar

is the same as

"foo " +
"bar".

So

foo\
bar

is treated as "foobar". If what we're doing is different from a standard convention maybe we should change it. I suspect nobody actually wants the behavior where there's no space between the previous line and the next one, so we could just insert it...

[tnorbye]

Hmmm a quick test makes it seem like at least shells behave the same way. So for the source code in https://github.com/slackhq/compose-lints/blob/main/compose-lint-checks/src/main/java/slack/lint/compose/ComposableFunctionNamingDetector.kt for example, I think the issue explanation should have an extra space before the \ on most lines.