Failing to parse valid Java 21 syntax: case when statement

[jaredstehler]

Describe the bug The semgrep parser is failing on the following valid Java 21 syntax:

  private static String calculateColor(Integer value) {
    return switch (value) {
      case Integer i when i <= -10 -> NEGATIVE_COLOR;
      case Integer i when i >= 10 -> POSITIVE_COLOR;
      default -> NEUTRAL_COLOR;
    };
  }

with the error message:

 **Semgrep encountered the following errors:**
	- Repro.java failed to parse. Does it contain a syntax error?

Verbose:
	- Syntax error at line /var/folders/q3/kq6rb1b550d7rd_pw9p7pw7c0000gq/T/tmp-371001d04VPucUAst/workspace/sources/head/MyProject/src/main/java/Repro.java:49:
 `-10 ->` was unexpected

To Reproduce Steps to reproduce the behavior, ideally a link to https://semgrep.dev:

https://semgrep.dev/playground/r/pKU1ven/hubspot.java-21-parse-fail-case-when

Expected behavior A clear and concise description of what you expected to happen.

Screenshots If applicable, add screenshots to help explain your problem.

What is the priority of the bug to you?

• [x] P0: blocking your adoption of Semgrep or workflow
• [ ] P1: important to fix or quite annoying
• [ ] P2: regular bug that should get fixed

Environment Observed with semgrep python package up to 1.74.0, and on semgrep.dev.

Use case What will fixing this bug enable for you?