BUG #18138: Using limit on VALUES causes type conversion to fail.

The following bug has been logged on the website:

Bug reference: 18138
Logged by: Akash Kava
Email address: ackava(at)gmail(dot)com
PostgreSQL version: 15.4
Operating system: alpine
Description:

Doing UPSERT is not easy and I know it is a complicated process. However,
since UPDATE has a WHERE clause, there is no way we can do conditional
INSERT.

But I was able to find a workaround, using LIMIT keyword with VALUES. I am
aware of the ON CONFLICT clause, but the issue with ON CONFLICT is, it
increases identity every time we want to update a row.

INSERT INTO the_table(column_1, column_2)
VALUES ($1, $2)
LIMIT LEAST((SELECT 1 FROM the_table WHERE key_1 = $3),2)-1

Basically this is a part of a larger query I have explained here.
https://stackoverflow.com/a/77190090/85597

This works as expected except for boolean and date fields.

Here is the example,
https://www.db-fiddle.com/f/g4LMVToHjrbYTDXT4MB1K/2

insert into avatar(username,url,is_public)
values ('a','b', 'true');

insert into avatar(username,url)
values ('a1','b')
limit LEAST((SELECT 1 FROM avatar),2)-1;

insert into avatar(username,url,is_public)
values ('a2','b', 'true')
limit LEAST((SELECT 1 FROM avatar),2)-1;

The problem occurs when we are sending data from node-postgres library.

Is there any work around? IF this will work correctly, we will be able to
use UPSERT easily without having gaps in identity sequences.