String Templates Formatting for """ Multi-Line is "not nice"

[vorburger]

#981 introduced JEP-430 / JEP-459 String Templates support.

This works great (~leaves it alone) for "single line", e.g. var html = STR."<table class=\"\{cssClass}\">";

However when exploring using this for """ Multi-Line it currently formats like this:

return STR."""
<table class="\{
        s(cssClass)}">
<tbody>

</tbody>
</table>
""";

To my eyes, that line break (as if it was a Builder type thing, presumably?) looks fairly "ugly"; I would expect it to simply look like this instead:

return STR."""
<table class="\{s(cssClass)}">
<tbody>

</tbody>
</table>
""";

Do folks agree?

@cushon

[sormuras]

Agreed. The extra line-break happens with 1.19.2, version 1.19.1 does not introduce it.

[cushon]

I agree this is not ideal. I think the specific change in 1.19.2 was 38de9c4, prior to that code inside \{ ... } wasn't getting reformatted at all. I think we want to keep formatting complex expressions inside placeholders, but it would be nice to avoid the line breaks in this situation.

[vorburger]

This works great (~leaves it alone) for "single line", e.g. var html = STR."<table class="{cssClass}">";

Or does it? I just ran into the following, and am surprised I didn't run into this previously (it's likely because I reinstalled tools from scratch, so it's possible my google-java-format changed and upgraded, it looks like it's running the latest 1.19.2 now, as configured, it's possible I may have been running an older version before somehow, I'm not 100% sure anymore):

$ git clone https://github.com/enola-dev/enola.git
$ git checkout 983f7ee
$ ./test.sh
$ source .venv/bin/activate [.fish, or not; depending on your shell]
$ pre-commit run --all-files

Google Java Formatter....................................................Failed
- hook id: pretty-format-java
- exit code: 1

[cwd=/home/vorburger/git/github.com/vorburger/enola] Run command: ('java', '-version')
[return_code=0] | 
	stderr: openjdk version "17.0.9" 2023-10-17
OpenJDK Runtime Environment (build 17.0.9+9-Debian-2)
OpenJDK 64-Bit Server VM (build 17.0.9+9-Debian-2, mixed mode, sharing)

Downloading https://github.com/google/google-java-format/releases/download/v1.19.2/google-java-format-1.19.2-all-deps.jar
[cwd=/home/vorburger/git/github.com/vorburger/enola] Run command: ('java', '--add-exports', 'jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED', '--add-exports', 'jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED', '--add-exports', 'jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED', '--add-exports', 'jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED', '--add-exports', 'jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED', '-jar', '/home/vorburger/.cache/pre-commit/google-java-formatter1.19.2.jar', '--set-exit-if-changed', '--aosp', '--replace', 

(...)

[return_code=1] | 
	stderr: tools/hello/src/main/java/dev/enola/common/hello/Hello.java:30:30: error: illegal escape character
tools/hello/src/main/java/dev/enola/common/hello/Library.java:27:30: error: illegal escape character
web/ui/src/main/java/dev/enola/web/ui/ThingUI.java:72:50: error: illegal escape character
web/ui/src/main/java/dev/enola/web/ui/ThingUI.java:73:34: error: illegal escape character

[cushon]

@vorburger the illegal escape character error is because you're running the formatting on JDK 17, which predates string template support. Using JDK 21 instead will resolve that error.