[Repo Assist] fix: improve delegate type tooltips using FSharpDelegateSignature API

[github-actions]

🤖 This is an automated pull request from Repo Assist.

Fixes #627 — Tooltips for delegates are terrible

Root Cause

The delegateTip function in both SignatureFormatter.fs and DocumentationFormatter.fs was calling getFuncSignatureWithIdent on the delegate's Invoke method with ident=6. This function is designed for member signatures with alignment padding, producing awkward multi-line output for delegates.

For no-argument delegates (e.g. System.Action), the result was especially broken: the [ [] ] branch with isDelegate=true returned just "unit" with no indentation, giving:

type Action =
   delegate of
unit
```

For delegates with parameters, the output had excessive indentation and the `->` return arrow on its own indented line:

```
type MyDelegate =
   delegate of
      arg: string
         -> int
```

## Fix

Replace the `Invoke`-method approach with direct use of `FSharpEntity.FSharpDelegateSignature`, which provides:
- `DelegateArguments`: list of `(string option * FSharpType)` — optional parameter name + type
- `DelegateReturnType`: the return type

This produces a clean, single-line format consistent with F# delegate syntax:

```
type MyDelegate =
   delegate of arg: string -> int

type Action =
   delegate of unit -> unit

type Func<'T1,'T2,'TResult> =
   delegate of arg1: 'T1 * arg2: 'T2 -> 'TResult

Changes

• src/FsAutoComplete.Core/SignatureFormatter.fs — updated delegateTip
• src/FsAutoComplete.Core/DocumentationFormatter.fs — updated delegateTip

Test Status

✅ src/FsAutoComplete.Core builds successfully (dotnet build -f net8.0)
✅ src/FsAutoComplete (main LSP server) builds successfully
✅ Code formatted with dotnet fantomas (no changes needed)

Note: The full solution build has a pre-existing failure in test/FsAutoComplete.DependencyManager.Dummy targeting netstandard2.0 only, unrelated to these changes.

Generated by Repo Assist for issue #627

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[Krzysztof-Cieslak]

/repo-assist add tests to it, including e2e hover test

[github-actions]

Commit pushed: 718b701

Generated by Repo Assist

[github-actions]

🤖 This is an automated response from Repo Assist.

Done! I've added tests for the delegate tooltip fix. Here's what was added:

E2E Hover Tests (SignatureFormatter path)

Added 4 verifySignature test cases to the tooltipTests function in CoreTests.fs, using new delegate type declarations in TestCases/Tooltips/Script.fsx:

Type	Expected hover signature
type NoArgDelegate = delegate of unit -> unit	type NoArgDelegate = delegate of unit -> unit
type SingleArgDelegate = delegate of arg: string -> int	type SingleArgDelegate = delegate of arg: string -> int
type MultiArgDelegate = delegate of a: string * b: int -> bool	type MultiArgDelegate = delegate of a: string * b: int -> bool
type UnannotatedDelegate = delegate of string -> int	type UnannotatedDelegate = delegate of string -> int

These exercise the verifySignature hover assertion, which tests SignatureFormatter.delegateTip.

DocumentationFormatter Test

Added one test case to InfoPanelTests.fs using server.FSharpDocumentation (the info panel endpoint) with a delegate type in TestCases/FormattedDocumentation/Script.fsx. This covers the parallel change in DocumentationFormatter.delegateTip.

Build status

✅ Build succeeded (dotnet build -f net8.0) with 0 warnings and 0 errors after fantomas formatting.

The LSP integration tests require full server startup (~5–10 min) and cannot run inline in this environment, so test execution was not completed here — CI will validate them.

Generated by Repo Assist for issue #1485

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/repo-assist.md@afb00b92a9514fee9a14c583f059a03d05738f70