Improve error reporting: ambiguous override method in object expression

[edgarfgp]

Description

Fixes #1429

Before

(Error 358, Line 7, Col 5, Line 9, Col 48, "The override for 'Overloaded: int -> bool' was ambiguous")

After

(Error 358, Line 8, Col 19, Line 8, Col 29, "The override for 'Overloaded: int -> bool' was ambiguous")

Rationale:

• Show the first ambiguous override instead of the object expression range
• Only showing the first ambiguous override should be fine as once you add type annotations all the ambiguities will disappear.

Alternative:

• Show one error for each ambiguous overload which can be noisy.

Checklist

• Test cases added
• Release notes entry updated

[github-actions]

❗ Release notes required

---

✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
src/Compiler	docs/release-notes/.FSharp.Compiler.Service/8.0.300.md

[psfinaki]

Thanks, it makes things better.

The original issue says that for some reason FSI was reporting different error - did you manage to figure out that discrepancy? What does it show now?

[edgarfgp]

The original issue says that for some reason FSI was reporting a different error - did you manage to figure out that discrepancy? What does it show now?

@psfinaki Yeah I tried running this on fsi. As far I can tell it shows the same error. See

[psfinaki]

Alrighty, thanks!

[T-Gro]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[vzarytovskii]

nice, thanks

[edgarfgp]

nice, thanks

More coming :) . This was raised by some students in one of our AmplifyingF# Essential lectures. See https://amplifyingfsharp.io/fsharp-essentials/