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[NUnit] Non provided generics is inferred to obj making test fails #274
Description
Description
I am testing an API which returns Result<'Success, 'Error>, my problem is that type inference is not fully propagating to the type making it resolved the unknown generic to obj instead of the correct type.
This makes the tests fails, and the cause of the failure is not obvious when looking at the message:
A total of 1 test files matched the specified pattern.
Failed fails [42 ms]
Error Message:
Assert.That(, )
Expected: Ok { Type = "feat" } or Ok { Type = "feat" }
But was: Ok { Type = "feat" }
Stack Trace:
at FsUnit.TopLevelOperators.should[a,a](FSharpFunc`2 f, a x, Object actual)
at Parser.validateFirstLine.fails() in /Users/mmangel/Workspaces/Github/easybuild-org/commit-linter/tests/Parser.fs:line 16
1) at FsUnit.TopLevelOperators.should[a,a](FSharpFunc`2 f, a x, Object actual)
at Parser.validateFirstLine.fails() in /Users/mmangel/Workspaces/Github/easybuild-org/commit-linter/tests/Parser.fs:line 16
Failed! - Failed: 1, Passed: 0, Skipped: 0, Total: 1, Duration: 42 ms - EasyBuild.CommitLinter.Tests.dll (net8.0)
Repro steps
module Parser
open NUnit.Framework
open FsUnit
open CommitLinter
module validateFirstLine =
type CommitMessage = { Type: string }
let expectedTyped: Result<_, string> = { Type = "feat" } |> Ok
[<Test>]
let fails () =
{ Type = "feat" } |> Ok
|> should equal expectedTypedExpected behavior
The test should pass.
Actual behavior
Test is failing
Known workarounds
If you enforce the type then the test pass:
module validateFirstLine =
type CommitMessage = { Type: string }
let expectedTyped: Result<_, string> = { Type = "feat" } |> Ok
[<Test>]
let fails () =
({ Type = "feat" } |> Ok : Result<CommitMessage, string>) // See that here I am forcing the type resolution
|> should equal expectedTypedRelated information
- Operating system: OSX
- Branch
- .NET Runtime, CoreCLR or Mono Version: .NET 8
- Performance information, links to performance testing scripts
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CaptnCodr commentedon May 25, 2024
Hi @MangelMaxime,
sorry for the delay.
I have no solution for you. We already had those issues with type inference in previous issues ( #189 , #198 ).
I would have suggested what you already encountered and provided in "Known workaround".
Have a wonderful day.
MangelMaxime commentedon May 25, 2024
Hello @CaptnCodr,
If you think there is no solution or way to warn about it then we can close this issue.