[Bug]: Unable to identify error in PostgreSQL DB query results

[chalindukodikara]

Description

public isolated function searchKind() returns error? {

    int port = 8080;

    sql:ParameterizedQuery kindSearchQuery =
            `SELECT * FROM component WHERE (kind #> Array['spec', 'build', 'buildpack', 'port']) @> ${port}`;
    stream<ComponentKindResultStream, sql:Error?> componentKindResultStream = dbClient->query(kindSearchQuery);
    if componentKindResultStream is stream<ComponentKindResultStream> {
        ComponentKindResultStream[] componentKinds = from var x in componentKindResultStream
            let var idValue = x.id, var kindValue = x.kind
            group by idValue, kindValue
            select {
                id: idValue,
                kind: kindValue
            };
        io:println(componentKinds);
    }

}

dbClient->query produces an error but if condition is true. It should not go inside the if condition since there is an error.

Steps to Reproduce

DB is PostgreSQL. 2 columns

• id (auto incrementing integer)

• kind (jsonb format)

  kind example {"kind": "Component", "spec": {"type": "byocService", "build": {"buildpack": {"port": 8080, "version": "1.x", "language": "java", "outputDir": "build/", "nodeVersion": "16.3.0", "buildCommand": "npm run build", "dockerfilePath": "multi-protocol-service/Dockerfile", "dockerContextPath": "multi-protocol-service"}}, "source": {"github": {"path": "go/greeter", "repository": "https://github.com/Mirage20/byoc-service"}, "bitbucket": {"path": "go/greeter", "repository": "https://bitbucket.example.com/Mirage20/byoc-service"}}}, "status": {"phase": "Pending", "createdAt": "2021-06-01T12:00:00Z", "updatedAt": "2021-06-01T12:00:00Z", "componentId": "12345678-1234-1234-1234-123456789012"}, "metadata": {"name": "component1", "description": "Component 1", "displayName": "Component 1", "projectName": "project1"}, "apiVersion": "core.choreo.dev/v1alpha1"}

Affected Version(s)

No response

OS, DB, other environment details and versions

No response

Related area

-> Compilation

Related issue(s) (optional)

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Suggested label(s) (optional)

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Suggested assignee(s) (optional)

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[MaryamZi]

This works as expected with a stream implementor, so could be an issue with how the stream is created or the value/type creator.

import ballerina/sql;
import ballerina/io;

type ComponentKindResultStream record {
    string id;
    string kind;
};

class StreamImplementor {
    public isolated function next() returns record {|ComponentKindResultStream value;|}|sql:Error {
        return error sql:Error("this is error");
    }
}

public function main() {
    stream<ComponentKindResultStream, sql:Error?> componentKindResultStream = new (new StreamImplementor()); 
    if componentKindResultStream is stream<ComponentKindResultStream> {
        io:println("Is stream<ComponentKindResultStream>");
        ComponentKindResultStream[] _ = from var x in componentKindResultStream
            let var idValue = x.id, var kindValue = x.kind
            group by idValue, kindValue
            select {
                id: idValue,
                kind: kindValue
            };
    } else {
        io:println("Not stream<ComponentKindResultStream>");
    }
}

Prints "Not stream\".