Single if cleanup should not concatenate instanceofs that use pattern matching

[jjohnstn]

Running Single if cleanup on the following:

public class BadInstanceOfMerge {
	protected String getTipWidget(Number number) {

		if (number instanceof Long n) {
			return n.toString();
		}
		if (number instanceof Float n) {
			return n.toString();
		}
		if (number instanceof Double n) {
			return n.toString();
		}

		return "";
	}
}

results in:

public class BadInstanceOfMerge {
	protected String getTipWidget(Number number) {

		if ((number instanceof Long n) || (number instanceof Float n) || (number instanceof Double n)) {
			return n.toString();
		}

		return "";
	}
}

part of #1197

[dg444]

This issue is not fixed in Eclipse 4.34.0 2024-12.
Example1:
if (number instanceof Long n) {
return n.toString();
}
else if (number instanceof Float n) {
return n.toString();
}
else if (number instanceof Double n) {
return n.toString();
}
=> fails to compile:
if ((number instanceof Long n) || (number instanceof Float n) || (number instanceof Double n)) {
return n.toString();
}
Example 2:
if (e instanceof IOException io)
throw io;
else if (e.getCause() instanceof IOException io)
throw io;
=> fails to compile:
f ((e instanceof IOException io) || (e.getCause() instanceof IOException io))
throw io;

[jjohnstn]

There are actually 2 cleanups referenced here. One cleanup combines the multiple ifs as mentioned in the original description. That cleanup was fixed. The other cleanup merges conditions of an if/else if/else. That issue (Bugzilla 570171) should not have been closed. I will post a fix shortly for 2025-03 M2