fix: to correct value of pursArgs in findFlag in Path.hs

[knight9999]

Description of the change

This PR is to fix the bug that the user can not spago run command when he specifies the output directory different from output.

• The Issue I found

Support user wants to specify output directory, for example, output2 directory.

The build can be done by the command

$ spago build -u "-o output2"

However, the run leads to error by the command.

$ spago run -u "-o output2"

• Reason and how to fix in this PR

This issue is because findFlag function in Path.hs has a problem.
If we use

$ spago run -u "-o output2"

, the pursArgs is ["-o output2"], not ["-o", "output2"].

Therefore (x:y:xs) can not match the y = "output2".

Checklist:

• Added the change to the "Unreleased" section of the changelog
• Added some example of the new feature to the README
• Added a test for the contribution (if applicable)

P.S.: the above checks are not compulsory to get a change merged, so you may skip them. However, taking care of them will result in less work for the maintainers and will be much appreciated 😊

[f-f]

Hi @knight9999, thanks for contributing the fix! 👏

This was sort of a known bug for a while, but not enough people stumbled on the edge cases for it to be annoying. In fact you can see I left a "TODO add tests" just a few lines above your fix:

spago/src/Spago/Command/Path.hs

Lines 46 to 51 in 7dcd30d

	-- TODO tests:
	-- ["-o", "something"]
	-- ["--output", "something"]
	-- ["--output something"]
	-- [" -o something"]
	-- ["--output=something"]

It would be great if you could add these tests as part of this PR, as it might help catch any other bugs we might be introducing (for example, there seems to be a regression in the current tests)

[knight9999]

Thanks @f-f for the valuable advice.
Now I have just added the test case and improved my PR to support --output=something case.

There are some issues in test cases that are not related with my PR,
Please test by using Spec.hs as

module Spec (spec) where

import Test.Hspec

import qualified Spago.Command.PathSpec as PathSpec

spec :: Spec
spec = do
  describe "PathSpec"     PathSpec.spec

instead of the original one

{-# OPTIONS_GHC -F -pgmF hspec-discover -optF --module-name=Spec #-}

temporaly

[knight9999]

Thanks @f-f for the valuable advice.
Now I have just added the test case and improved my PR to support --output=something case.

There are some test issue other than my PR,
Please test by using Spec.hs as

module Spec (spec) where

import Test.Hspec

import qualified Spago.Command.PathSpec as PathSpec

spec :: Spec
spec = do
  describe "PathSpec"     PathSpec.spec

instead of the origin one

{-# OPTIONS_GHC -F -pgmF hspec-discover -optF --module-name=Spec #-}

[f-f]

I left a small comment but otherwise this looks great 👏

[knight9999]

Hi @f-f . Thank you very much.

[f-f]

Thank you 🙂