[Bug]: The code completion for annotation field is not working for some fields

[TharmiganK]

Description

When we have a union-typed field for an annotation (union of int and record) and when we try to give it as a record value, the code completions are not working properly.

Note: This tooling support is required for this new feature in the constraint package - ballerina-platform/module-ballerina-constraint#79

Steps to Reproduce

Check the following code in vscode:

annotation StringConstraints String on type, record field;

type ConstraintRecord record {|
    anydata value;
    string message;
|};

type StringConstraints record {|
    int|record{| *ConstraintRecord; int value; |} length?;
|};

@String {
    length : {} // enter the curly braces and try to type the field name it does not complete with the proper fields
}
type TestString string;

Affected Version(s)

Ballerina SwanLake 2201.6.0

OS, DB, other environment details and versions

Mac OS with Apple M1 chip

Related area

-> Editor

Related issue(s) (optional)

No response

Suggested label(s) (optional)

No response

Suggested assignee(s) (optional)

No response

[malinthar]

When investigated, I figured out that the ExpectedTypeAPI returns an invalid expected type at the cursor position depicted above. The syntax tree node at the cursor is a SpecificFieldNode.

The expected type API uses the NodeFinder class to find the BLangNode node in a given range. In the above case the range given (specic field node in the annotation attachment) is not within the range of any of the topLevel nodes. Therefore, the node finder return null when the lookup() method in the NodeFinder is called.

ballerina-lang/compiler/ballerina-lang/src/main/java/io/ballerina/compiler/api/impl/NodeFinder.java

Line 227 in 0abb334

BLangNode lookup(BLangCompilationUnit unit, LineRange range) {

[KavinduZoysa]

In the above example, we are trying to look up an annotAttachment by giving a pos inside it. First, we iterate over top-level nodes and the position of top-level nodes does not cover its' annotAttachment. That's why we are getting null here. We can,

1. lookup for annotAttachment for each top-level node separately or
2. extend the pos of the node to cover the annotAttachment.

For 2nd one, we need support from the parser and it is a change in the compiler front-end side. The 1st one can be done within NodeFinder.java and we have to check the other place that can have annotAttachements.

@hasithaa, @gimantha, @MaryamZi, @pcnfernando WDYT?

[hasithaa]

We can't do the 2, it is a backward incompatible change. +1 for 1st one.

[mindula]

Blocked by #41186

[github-actions]

This issue is NOT closed with a proper Reason/ label. Make sure to add proper reason label before closing. Please add or leave a comment with the proper reason label now.

      - Reason/EngineeringMistake - The issue occurred due to a mistake made in the past.
      - Reason/Regression - The issue has introduced a regression.
      - Reason/MultipleComponentInteraction - Issue occured due to interactions in multiple components.
      - Reason/Complex - Issue occurred due to complex scenario.
      - Reason/Invalid - Issue is invalid.
      - Reason/Other - None of the above cases.