How to use HUnit in Stack - haskell

I have a stackproject stapro with a file app/Main.hs
module Main where
import Lib
main = putStrLn "This is main"
foo::Int ->Int
foo = (+1)
and a file test/Spec.hs
module Spec where
import Test.HUnit
import Main (foo)
main :: IO ()
main = putStrLn "Test suite not yet implemented"
testFoo :: Test
testFoo = TestCase $ assertEqual "Should return 2" 2 (foo 1)
When I try to execute the tests however
$ stack test
While constructing the BuildPlan the following exceptions were encountered:
-- While attempting to add dependency,
Could not find package Main in known packages
-- Failure when adding dependencies:
Main: needed (-any), stack configuration has no specified version
needed for package stapro-0.1.0.0
My .cabal file is
name: stapro
version: 0.1.0.0
...
build-type: Simple
-- extra-source-files:
cabal-version: >=1.10
library
hs-source-dirs: src
exposed-modules: Lib
build-depends: base >= 4.7 && < 5
default-language: Haskell2010
executable stapro-exe
hs-source-dirs: app
main-is: Main.hs
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends: base
, stapro
default-language: Haskell2010
test-suite stapro-test
type: exitcode-stdio-1.0
hs-source-dirs: test
main-is: Spec.hs
build-depends: base
, stapro
, HUnit
, Main
ghc-options: -threaded -rtsopts -with-rtsopts=-N
default-language: Haskell2010
...

It looks like you're trying to depend on the executable (Main in build-depends of the test-suite section), so that you can test it in your test suite. That doesn't work, in fact you can't really test your executable at all.
Remove Main from the build-depends. Move all the code you want to test into your library.

Related

Stack auto-removes dependency from .cabal file following 'stack build'

I want to work on a new Haskell project using the threepenny-gui package.
The first thing I did was create a stack project via $ stack new threepennydemo. From here, here, I did the following:
I edited the extra-deps section in my stack.yaml file from:
# extra-deps: []
to
extra-deps:
- threepenny-gui-0.9.0.0
I edited the .cabal file from:
library
exposed-modules:
Lib
other-modules:
Paths_threepennydemo
hs-source-dirs:
src
build-depends:
base >=4.7 && <5
default-language: Haskell2010
executable threepennydemo-exe
main-is: Main.hs
other-modules:
Paths_threepennydemo
hs-source-dirs:
app
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, threepennydemo
default-language: Haskell2010
test-suite threepennydemo-test
type: exitcode-stdio-1.0
main-is: Spec.hs
other-modules:
Paths_threepennydemo
hs-source-dirs:
test
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, threepennydemo
default-language: Haskell2010
to
library
exposed-modules:
Lib
other-modules:
Paths_threepennydemo
hs-source-dirs:
src
build-depends:
base >=4.7 && <5
, threepenny-gui >= 0.9
default-language: Haskell2010
executable threepennydemo-exe
main-is: Main.hs
other-modules:
Paths_threepennydemo
hs-source-dirs:
app
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, threepennydemo
, threepenny-gui >= 0.9
default-language: Haskell2010
test-suite threepennydemo-test
type: exitcode-stdio-1.0
main-is: Spec.hs
other-modules:
Paths_threepennydemo
hs-source-dirs:
test
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, threepennydemo
, threepenny-gui >= 0.9
default-language: Haskell2010
I edited the stock /app/Main.hs from:
module Main where
import Lib
main :: IO ()
main = someFunc
to
import Graphics.UI.Threepenny
main :: IO ()
main = do
startGUI defaultConfig showMessage
showMessage :: Window -> UI ()
showMessage window = do
getBody window #+ [string "Hello, world!"]
return ()
I enter the command $ stack build.
From here, I notice two things. The first is that I receive the following error:
Building all executables for `threepennydemo' once. After a successful build of all of them, only specified executables will be rebuilt.
threepennydemo> configure (lib + exe)
Configuring threepennydemo-0.1.0.0...
threepennydemo> build (lib + exe)
Preprocessing library for threepennydemo-0.1.0.0..
Building library for threepennydemo-0.1.0.0..
Preprocessing executable 'threepennydemo-exe' for threepennydemo-0.1.0.0..
Building executable 'threepennydemo-exe' for threepennydemo-0.1.0.0..
[1 of 2] Compiling Main
/Users/my_username/threepennydemo/app/Main.hs:1:1: error:
Could not load module ‘Graphics.UI.Threepenny’
It is a member of the hidden package ‘threepenny-gui-0.9.0.0’.
Perhaps you need to add ‘threepenny-gui’ to the build-depends in your .cabal file.
Use -v (or `:set -v` in ghci) to see a list of the files searched for.
|
1 | import Graphics.UI.Threepenny
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-- While building package threepennydemo-0.1.0.0 using:
/Users/my_username/.stack/setup-exe-cache/x86_64-osx/Cabal-simple_mPHDZzAJ_3.0.1.0_ghc-8.8.4 --builddir=.stack-work/dist/x86_64-osx/Cabal-3.0.1.0 build lib:threepennydemo exe:threepennydemo-exe --ghc-options " -fdiagnostics-color=always"
Process exited with code: ExitFailure 1
The second is that my .cabal file, edited as mentioned in 2., has automatically removed the edits I made to the file.
What am I missing in order to be able to use a third party library when setting up a new stack project?
My difficulty as the result of some confusion between stack.yaml and package.yaml. The latter being what generates the threepennydemo.cabal file. Hence, dependencies must also be specified to a package.yaml file. Adding this dependency to the package.yaml allowed $ stack build to complete without issue.

Problem loading module Data.Number.CReal in cabal file

I installed a simple proyect with stack, my stack.yaml looks like:
resolver: lts-14.6
packages:
- .
dependencies:
- base (>=3 && <5)
- numbers
and I have a simple code that only calls a function:
module Main where
import Lib
import Data.Number.CReal
main :: IO ()
main = someFunc
and the error is always the same:
numbers-play-0.1.0.0: unregistering (local file changes: numbers-play.cabal)
numbers-play> configure (lib + exe)
Configuring numbers-play-0.1.0.0...
numbers-play> build (lib + exe)
Preprocessing library for numbers-play-0.1.0.0..
Building library for numbers-play-0.1.0.0..
[1 of 2] Compiling Lib
[2 of 2] Compiling Paths_numbers_play
Preprocessing executable 'numbers-play-exe' for numbers-play-0.1.0.0..
Building executable 'numbers-play-exe' for numbers-play-0.1.0.0..
[1 of 2] Compiling Main [Data.Number.CReal changed]
/home/damian/dev/haskell/numbers-play/app/Main.hs:4:1: error:
Could not load module ‘Data.Number.CReal’
It is a member of the hidden package ‘numbers-3000.2.0.2’.
Perhaps you need to add ‘numbers’ to the build-depends in your .cabal file.
Use -v to see a list of the files searched for.
|
4 | import Data.Number.CReal
| ^^^^^^^^^^^^^^^^^^^^^^^^
My cabal file:
cabal-version: 1.12
-- This file has been generated from package.yaml by hpack version 0.31.2.
--
-- see: https://github.com/sol/hpack
--
-- hash: fb0ed9e8eb8062639f1d6a02a65d857d15b3265158925242287d4a8a885f8381
name: numbers-play
version: 0.1.0.0
description: Please see the README on GitHub at <https://github.com/githubuser/numbers-play#readme>
homepage: https://github.com/githubuser/numbers-play#readme
bug-reports: https://github.com/githubuser/numbers-play/issues
author: Author name here
maintainer: example#example.com
copyright: 2019 Author name here
license: BSD3
license-file: LICENSE
build-type: Simple
extra-source-files:
README.md
ChangeLog.md
source-repository head
type: git
location: https://github.com/githubuser/numbers-play
library
exposed-modules:
Lib
other-modules:
Paths_numbers_play
hs-source-dirs:
src
build-depends:
base >=4.7 && <5
default-language: Haskell2010
executable numbers-play-exe
main-is: Main.hs
other-modules:
Paths_numbers_play
hs-source-dirs:
app
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, numbers-play
default-language: Haskell2010
test-suite numbers-play-test
type: exitcode-stdio-1.0
main-is: Spec.hs
other-modules:
Paths_numbers_play
hs-source-dirs:
test
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, numbers-play
default-language: Haskell2010
How can I import it properly?
The dependencies field, which specifies the numbers dependency, should be in your package.yaml file (which Stack uses to generate the cabal file), and not in stack.yaml (which is for Stack-specific configuration, such as choosing the resolver).

Two executables in one cabal file; stack build does not recognize them

I'm trying to make 2 executables "project". All duplicates of this question did not help me - their answers don't fix my problem. I have .cabal file like this:
name: int-tests
version: 0.1.0.0
synopsis: Integration Tests Suite
description: Integration Tests Suite
license: AllRightsReserved
author: Author name here
maintainer: example#example.com
copyright: 2018 Author name here
build-type: Custom
extra-source-files: README.md
cabal-version: >=1.10
library
hs-source-dirs: common
exposed-modules: Common
build-depends: base
, text
, aeson
, network-uri
default-language: Haskell2010
ghc-options: -Wall -Werror
executable api-tests-exe
hs-source-dirs: api
main-is: Main.hs
ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall -Werror
build-depends: base
, hspec
, QuickCheck
default-language: Haskell2010
executable e2e-tests-exe
hs-source-dirs: e2e
main-is: Main.hs
ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall -Werror
build-depends: base
, hspec
, QuickCheck
default-language: Haskell2010
and when I call stack ide targets I don't see these 2 targets. So, stack build api-tests and stack build e2e-tests don't work too.
How can I create 2 targets' project for stack? I tried also package.yaml but result is the same. Stack version is 1.9.1. I have folders tree like:
api/
...
e2e/
...
where are Main.hs files with content like:
module Main (main) where
main :: IO ()
main = print "Hello"
Also I tried option -main-is Main but without success.
Error looks like:
Error: While constructing the build plan, the following exceptions were encountered:
Unknown package: api-tests
AFAIK, stack build always builds all your targets. But if you want to be run just one executable, you'll need the full name including the -exe. So, stack exec api-tests-exe and stack exec e2e-tests-exe.
But what you really want to do is make these test targets: https://www.haskell.org/cabal/users-guide/developing-packages.html#test-suites
Problem was in stack.yaml file, I had to add '.' folder to "packages:" section.

How to add dependencies and make it visible to Intero in Haskell

I want to use System.Directory in emacs with Haskell mode and Intero, While the on the fly check warns that Couldn't find module System.Directory. So I add some dependencies in my cabal file. And the warning doesn't disappear while the stack build successfully executed.
Below is my cabal file:
-- This file has been generated from package.yaml by hpack version 0.28.2.
--
-- see: https://github.com/sol/hpack
--
-- hash: 536b5f6ecaaec7d4b7a9694c8f69bbe648a1d21d80fa721e533ac5b139955401
name: find
version: 0.1.0.0
description: Please see the README on GitHub at <https://github.com/Handora/find#readme>
homepage: https://github.com/Handora/find#readme
bug-reports: https://github.com/Handora/find/issues
author: Handora
maintainer: qcdsr970209#gmail.com
copyright: Qian Chen
license: BSD3
license-file: LICENSE
build-type: Simple
cabal-version: >= 1.10
extra-source-files:
ChangeLog.md
README.md
source-repository head
type: git
location: https://github.com/Handora/find
library
exposed-modules:
Lib
RecursiveContents
other-modules:
Paths_find
hs-source-dirs:
src
build-depends:
base >=4.7 && <5
, directory
default-language: Haskell2010
executable find-exe
main-is: Main.hs
other-modules:
Paths_find
hs-source-dirs:
app
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, find
, directory
default-language: Haskell2010
test-suite find-test
type: exitcode-stdio-1.0
main-is: Spec.hs
other-modules:
Paths_find
hs-source-dirs:
test
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, find
default-language: Haskell2010
I add the directory into build dependencies and executable build dependencies. So my question is how to make the System.Directory visible to Intero, so the warnings can disappear.
You can get it to show up by running intero-restart.
There may be a "more correct" way, but this works.

Stack fails to build

I am trying to learn haskell here (don't ask why), and I am starting with a very simple code, that i even copied from github.
So the code is this:
module Example () where
import Network.HTTP
-- Non HTTPS
-- 1. Perform a basic HTTP get request and return the body
get :: String -> IO String
get url = simpleHTTP (getRequest url) >>= getResponseBody
-- 2. Get the response code
getCode :: String -> IO ResponseCode
getCode url = simpleHTTP req >>= getResponseCode
where req = getRequest url
However, when I run stack build I get this:
slack-client-0.1.0.0: build
Preprocessing library slack-client-0.1.0.0...
[2 of 2] Compiling Example ( src\Example.hs, .stack-work\dist\b7fec021\
build\Example.o )
D:\haskell\slack-client\src\Example.hs:3:1: error:
Failed to load interface for `Network.HTTP'
It is a member of the hidden package `HTTP-4000.3.3'.
Perhaps you need to add `HTTP' to the build-depends in your .cabal file.
Use -v to see a list of the files searched for.
-- While building package slack-client-0.1.0.0 using:
C:\Users\Mihai\AppData\Roaming\stack\setup-exe-cache\x86_64-windows\setup-
Simple-Cabal-1.24.0.0-ghc-8.0.1.exe --builddir=.stack-work\dist\b7fec021 build l
ib:slack-client exe:slack-client-exe --ghc-options " -ddump-hi -ddump-to-file"
Process exited with code: ExitFailure 1
This is my .cabal file:
name: slack-client
version: 0.1.0.0
synopsis: Initial project template from stack
description: Please see README.md
homepage: https://github.com/githubuser/slack-client#readme
license: BSD3
license-file: LICENSE
author: Author name here
maintainer: example#example.com
copyright: 2016 Author name here
category: Web
build-type: Simple
-- extra-source-files:
cabal-version: >=1.10
library
hs-source-dirs: src
exposed-modules: Lib
other-modules: Example
build-depends: base >= 4.7 && < 5
default-language: Haskell2010
executable slack-client-exe
hs-source-dirs: app
main-is: Main.hs
other-modules: Example
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends: base
, HTTP
, HTTP-Simple
, slack-client
default-language: Haskell2010
test-suite slack-client-test
type: exitcode-stdio-1.0
hs-source-dirs: test
main-is: Spec.hs
build-depends: base
, HTTP-Simple
, slack-client
ghc-options: -threaded -rtsopts -with-rtsopts=-N
default-language: Haskell2010
source-repository head
type: git
location: https://github.com/githubuser/slack-client
What am i doing wrong?
If you want your `Example module to be a part of executable, add to this section
executable slack-client-exe
hs-source-dirs: app
main-is: Main.hs
this line: other-modules: Example.
If you want it to be a part of the library, change
library
hs-source-dirs: src
exposed-modules: Lib
to
library
hs-source-dirs: src
exposed-modules: Lib, Example
And take a look at cabal documentation.

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