TypeProviders: Add inner base-exception description (#17251)

* TypeProviders: Add inner base-exception description

* Release notes docs updated

* Update src/Compiler/TypedTree/tainted.fs

Thanks @abelbraaksma

Co-authored-by: Abel Braaksma <[email protected]>

* Update docs/release-notes/.FSharp.Compiler.Service/8.0.400.md

Co-authored-by: Abel Braaksma <[email protected]>

* Added @abelbraaksma's suggestion

---------

Co-authored-by: Abel Braaksma <[email protected]>
Co-authored-by: Vlad Zarytovskii <[email protected]>
Co-authored-by: Petr <[email protected]>

Author: 4 people

docs/release-notes/.FSharp.Compiler.Service/8.0.400.md

@@ -25,6 +25,7 @@
 * Allow #nowarn to support the FS prefix on error codes to disable warnings ([Issue #17206](https://github.com/dotnet/fsharp/issues/16447), [PR #17209](https://github.com/dotnet/fsharp/pull/17209))
 * Allow ParsedHashDirectives to have argument types other than strings ([Issue #17240](https://github.com/dotnet/fsharp/issues/16447), [PR #17209](https://github.com/dotnet/fsharp/pull/17209))
 * Parser: better recovery for unfinished patterns ([PR #17231](https://github.com/dotnet/fsharp/pull/17231))
+* Expose inner exception information of TypeProviders to help diagnostics in IDE ([PR #17251](https://github.com/dotnet/fsharp/pull/17251))
 * Parser: recover on empty match clause ([PR #17233](https://github.com/dotnet/fsharp/pull/17233))
 
 ### Changed

src/Compiler/TypedTree/tainted.fs

@@ -101,11 +101,12 @@ type internal Tainted<'T> (context: TaintedContext, value: 'T) =
             | :? TypeProviderError -> reraise()
             | :? AggregateException as ae ->
                     let errNum,_ = FSComp.SR.etProviderError("", "")
-                    let messages = [for e in ae.InnerExceptions -> e.Message]
+                    let messages = [for e in ae.InnerExceptions -> if isNull e.InnerException then e.Message else (e.Message + ": " + e.GetBaseException().Message)]
                     raise <| TypeProviderError(errNum, this.TypeProviderDesignation, range, messages)
             | e -> 
                     let errNum,_ = FSComp.SR.etProviderError("", "")
-                    raise <| TypeProviderError((errNum, e.Message), this.TypeProviderDesignation, range)
+                    let error = if isNull e.InnerException then e.Message else (e.Message + ": " + e.GetBaseException().Message)
+                    raise <| TypeProviderError((errNum, error), this.TypeProviderDesignation, range)
 
     member _.TypeProvider = Tainted<_>(context, context.TypeProvider)