Fail to reformat by JDK17 for Pattern Matching for instanceof

[bluebu]

https://openjdk.java.net/jeps/394

idea version: 2021.3.2 (Ultimate Edition)

plugin version: 1.15.0.0

JDK version: Amazon corretto 17.0.2

the reformat doesn't work, if has the code below:

if (a instanceof String str) {
   System.out.println(str)
}

the reformat will work, if I delete any code with "Pattern Matching for instanceof" operator

[MatthewRyanRead]

Reproduced in 2022.1.2 with plugin 1.15.0.0 (formatter 1.15.0) on Temurin-17.0.2+8.

https://github.com/spotify/fmt-maven-plugin and https://github.com/diffplug/spotless both appear to handle this construction perfectly, so it seems specific to the IntelliJ plugin rather than to the library generally.

[tbroyer]

Is this when running IDEA itself with JDK 17 ? or only using JDK 17 as the "project JDK" ?

See #533

[MatthewRyanRead]

I was using 17 as the project JDK while using the default 11 runtime for the IDE.

However, I can also reproduce this on the 2022.2 EAP version of IntelliJ, which runs on their bundled 17.0.3+7-469.3-jcef runtime at the moment.

[zxeoc]

In my case, it works fine with project JDK 17 & JBR 11. It fails after I update IDEA to 2022.2, which switches to JBR 17 by default.

[tbroyer]

IIRC, #533 is about using the appropriate JDK (JBR) for running the IDE (corresponding to your project JDK, i.e. you can't use JBR 11 to format Java 17 code), and #787 when using 2022.2.

[cushon]

I think this is covered by the issues @tbroyer mentioned. The formatter itself can handle these constructs, but only when running on a JVM that supports them:

java -jar google-java-format-1.15.0-all-deps.jar T.java
class T {
  {
    if (a instanceof String str) {
      System.out.println(str);
    }
  }
}