Missing autocomplete suggestions in Eclipse 2025-12 / 6.1.0.v202601011803-e2512

[ssadedin]

I'm experiencing a very similar problem to #1635 but now in Eclipse 2025-12.

The problem manifests in a way that makes me think it's more a Groovy-Eclipse issue than not. Specifically, I DO get completions as soon as I type at least one letter of the word for it to complete. But I get NO completions when it has no characters to complete (eg: just a . character). It seems to me Groovy is able to succesfully generate completions, they just aren't showing when there are no characters to search for. I am wondering if a different method is used under the hood when there are no characters vs some characters to filter by.

Example code:

package test

class Plant  {
    String leaves = "green"
}

class Cactus {
    
    Plant plant = new Plant()
    
    void blonk() {
        println this.plant
    }
}

Typing this. and pressing Ctrl+Space gives:

But if I give it a single character and ask to complete that then I get everything with that character in it:

I have installed 2025-09 along with the associated Groovy-Eclipse and I do NOT see the issue there (which is interesting because it was reported there in the previous report). Is it possible the fix did not get carried over to the release for 2025-12?

I am using Eclipse 2025-12 on Mac with the bundled JRE:

openjdk 21.0.9 2025-10-21 LTS
OpenJDK Runtime Environment Temurin-21.0.9+10 (build 21.0.9+10-LTS)
OpenJDK 64-Bit Server VM Temurin-21.0.9+10 (build 21.0.9+10-LTS, mixed mode, sharing)

The JRE is nearly identical to that in 2025-09 where I don't have the problem, so I doubt it is the cause.

There are no errors in the error log.

Versions of software:

Thank you for any help or suggestions for how to fix or workaround this! It definitely impedes efficiency to not have the autocomplete working.

[ssadedin]

DEBUGGING

I did a little bit of debugging on my end.

I attached with a debugger and compared what happens in the completion code that is different when I try to complete this. vs this.b. The problem seems to be that the CompletionNodeFinder is unable to create a ContentAssistContext.

I looked at the input to that function and saw that the compile unit is quite different going in, right from the point at which it is passed in from the JDT code.

Completing this.
Completing this.b

The stack frame above this is coming directly from JDT so it seems like this may be a difference coming from other Eclipse code.

[eric-milles]

You can disable the new parser with system property -Dgroovy.antlr4=false (add to your eclipse.ini). The old parser includes error-recovery so that incomplete expressions like "this." still produce a viable AST. This is required for code completions.

Starting in 6.0.0 the antlr4 parser is left enabled by default.

see #1011

[ssadedin]

Starting in 6.0.0 the antlr4 parser is left enabled by default.

My apologies! I didn't realise that change had happened. It makes total sense now what is happening.