haskell_x_docker_x_vscode

Build a Haskell development environment with Docker x VSCode.

Supplemental Environmental Description

Installed VSCode extensions.

https://marketplace.visualstudio.com/items?itemName=haskell.haskell
Docker images use the LATEST tag.

https://hub.docker.com/_/haskell
Install the doctest package.

https://hackage.haskell.org/package/doctest
GHCup is required for VSCode extensions, so install it.

https://www.haskell.org/ghcup/install/
Installed haskell language server (hls), which seems to be required for VSCode extensions.

https://haskell-language-server.readthedocs.io/en/latest/installation.html#visual-studio-code

As of 2023/03/18, version 1.9.1.0 was required.
```
ghcup install hls 1.9.1.0
```

Project Creation

There are two types: stack and cabal. cabal was used.¹

mkdir -p "Directory path for the project"
cd "Directory path for the project"
cabal update
cabal init

The selections for cabal init were as follows.

What does the package build:
   1) Library
 * 2) Executable
   3) Library and Executable
   4) Test suite
Your choice? [default: Executable] 3
Do you wish to overwrite existing files (backups will be created) (y/n)? [default: n] y
Please choose version of the Cabal specification to use:
   1) 1.24  (legacy)
   2) 2.0   (+ support for Backpack, internal sub-libs, '^>=' operator)
   3) 2.2   (+ support for 'common', 'elif', redundant commas, SPDX)
   4) 2.4   (+ support for '**' globbing)
 * 5) 3.0   (+ set notation for ==, common stanzas in ifs, more redundant commas, better pkgconfig-depends)
   6) 3.4   (+ sublibraries in 'mixins', optional 'default-language')
Your choice? [default: 3.0] 
Package name? [default: helloworld] 
Package version? [default: 0.1.0.0] 
Please choose a license:
   1) BSD-2-Clause
   2) BSD-3-Clause
   3) Apache-2.0
   4) MIT
   5) MPL-2.0
   6) ISC
   7) GPL-2.0-only
   8) GPL-3.0-only
   9) LGPL-2.1-only
  10) LGPL-3.0-only
  11) AGPL-3.0-only
  12) GPL-2.0-or-later
  13) GPL-3.0-or-later
  14) LGPL-2.1-or-later
  15) LGPL-3.0-or-later
  16) AGPL-3.0-or-later
  17) Other (specify)
Your choice? 4
Author name? [default: xxxx] 
Maintainer email? [default: xxxx] 
Project homepage URL? [optional] 
Project synopsis? [optional] 
Project category:
   1) Codec
   2) Concurrency
   3) Control
   4) Data
   5) Database
   6) Development
   7) Distribution
   8) Game
   9) Graphics
  10) Language
  11) Math
  12) Network
  13) Sound
  14) System
  15) Testing
  16) Text
  17) Web
  18) Other (specify)
Your choice? [default: (none)] 
Library source directory:
 * 1) src
   2) lib
   3) src-lib
   4) Other (specify)
Your choice? [default: src] 
Choose a language for your library:
 * 1) Haskell2010
   2) Haskell98
   3) GHC2021 (requires at least GHC 9.2)
   4) Other (specify)
Your choice? [default: Haskell2010] 
What is the main module of the executable:
 * 1) Main.hs
   2) Main.lhs
   3) Other (specify)
Your choice? [default: Main.hs] 
Application directory:
 * 1) app
   2) exe
   3) src-exe
   4) Other (specify)
Your choice? [default: app] 
Choose a language for your executable:
 * 1) Haskell2010
   2) Haskell98
   3) GHC2021 (requires at least GHC 9.2)
   4) Other (specify)
Your choice? [default: Haskell2010] 
Should I generate a test suite for the library? [default: y] 
What is the main module of the test suite?:
 * 1) Main.hs
   2) Main.lhs
   3) Other (specify)
Your choice? [default: Main.hs] 
Test directory? [default: test] 
Choose a language for your test suite:
 * 1) Haskell2010
   2) Haskell98
   3) GHC2021 (requires at least GHC 9.2)
   4) Other (specify)
Your choice? [default: Haskell2010] 
Add informative comments to each field in the cabal file. (y/n)? [default: y] 
[Log] Using cabal specification: 3.0
[Log] Creating fresh file LICENSE...
[Log] Creating fresh file CHANGELOG.md...
[Log] Creating fresh directory ./src...
[Log] Creating fresh file src/MyLib.hs...
[Log] Creating fresh directory ./app...
[Log] Creating fresh file app/Main.hs...
[Log] Creating fresh directory ./test...
[Log] Creating fresh file test/Main.hs...
[Log] Creating fresh file helloworld.cabal...
[Warning] No synopsis given. You should edit the .cabal file and add one.
[Info] You may want to edit the .cabal file and add a Description field.

Build and Run

The source code is to output "Hello, Haskell!" to standard output when the project is created with cabal init. You can build and run the project with cabal run.

root@f3d42513a02c:/workspace/projects/helloworld# cabal run
Resolving dependencies...
Build profile: -w ghc-9.4.4 -O1
In order, the following will be built (use -v for more details):
 - helloworld-0.1.0.0 (lib) (first run)
 - helloworld-0.1.0.0 (exe:helloworld) (first run)
Configuring library for helloworld-0.1.0.0..
Preprocessing library for helloworld-0.1.0.0..
Building library for helloworld-0.1.0.0..
[1 of 1] Compiling MyLib            ( src/MyLib.hs, /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/build/MyLib.o, /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/build/MyLib.dyn_o )
Configuring executable 'helloworld' for helloworld-0.1.0.0..
Preprocessing executable 'helloworld' for helloworld-0.1.0.0..
Building executable 'helloworld' for helloworld-0.1.0.0..
[1 of 1] Compiling Main             ( app/Main.hs, /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/x/helloworld/build/helloworld/helloworld-tmp/Main.o )
[2 of 2] Linking /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/x/helloworld/build/helloworld/helloworld
Hello, Haskell!
someFunc
root@f3d42513a02c:/workspace/projects/helloworld#

Test

Run tests with cabal test.

doctest

Add the doctest configuration to the cabal file.

test-suite doctest
    type:                 exitcode-stdio-1.0
    default-language:     Haskell2010
    hs-source-dirs:       test/doctest
    ghc-options:          -Wall
    main-is:              doctest.hs
    build-depends:        base
                        , doctest

Create the source specified in the main-is of the cabal file.

module Main where

import Test.DocTest

main :: IO ()
main = doctest ["src/MyLib.hs", "app/Main.hs"]

Write a doctest. The following source is an example of app/Main.hs.

before

main :: IO ()
main = do
  putStrLn "Hello, Haskell!"
  MyLib.someFunc

after

-- |
-- Entry point
-- >>> main
-- Hello, Haskell!
-- someFunc
main :: IO ()
main = do
  putStrLn "Hello, Haskell!"
  MyLib.someFunc

Run tests with cabal test.

root@8c6481710a1b:/workspace/projects/helloworld# cabal test; echo $?
Build profile: -w ghc-9.4.4 -O1
In order, the following will be built (use -v for more details):
 - helloworld-0.1.0.0 (test:doctest) (first run)
 - helloworld-0.1.0.0 (test:helloworld-test) (first run)
Preprocessing test suite 'doctest' for helloworld-0.1.0.0..
Preprocessing test suite 'helloworld-test' for helloworld-0.1.0.0..
Building test suite 'helloworld-test' for helloworld-0.1.0.0..
Building test suite 'doctest' for helloworld-0.1.0.0..
Running 1 test suites...
Test suite helloworld-test: RUNNING...
Test suite helloworld-test: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/helloworld-test/test/helloworld-0.1.0.0-helloworld-test.log
1 of 1 test suites (1 of 1 test cases) passed.
Running 1 test suites...
Test suite doctest: RUNNING...
Test suite doctest: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/doctest/test/helloworld-0.1.0.0-doctest.log
1 of 1 test suites (1 of 1 test cases) passed.
0
root@8c6481710a1b:/workspace/projects/helloworld#

The output when there is a NG in the test is as follows.

root@8c6481710a1b:/workspace/projects/helloworld# cabal test; echo $?
Build profile: -w ghc-9.4.4 -O1
In order, the following will be built (use -v for more details):
 - helloworld-0.1.0.0 (test:doctest) (first run)
 - helloworld-0.1.0.0 (test:helloworld-test) (first run)
Preprocessing test suite 'helloworld-test' for helloworld-0.1.0.0..
Preprocessing test suite 'doctest' for helloworld-0.1.0.0..
Building test suite 'helloworld-test' for helloworld-0.1.0.0..
Building test suite 'doctest' for helloworld-0.1.0.0..
Running 1 test suites...
Test suite helloworld-test: RUNNING...
Test suite helloworld-test: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/helloworld-test/test/helloworld-0.1.0.0-helloworld-test.log
1 of 1 test suites (1 of 1 test cases) passed.
Running 1 test suites...
Test suite doctest: RUNNING...
app/Main.hs:7: failure in expression `main'
expected: Hello, Haskell
          someFunc
 but got: Hello, Haskell!
                        ^
          someFunc

Examples: 2  Tried: 2  Errors: 0  Failures: 1

Test suite doctest: FAIL
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/doctest/test/helloworld-0.1.0.0-doctest.log
0 of 1 test suites (0 of 1 test cases) passed.
Error: cabal: Tests failed for test:doctest from helloworld-0.1.0.0.

1
root@8c6481710a1b:/workspace/projects/helloworld#

HSpec

Add HSpec configuration to the cabal file.

test-suite spec
    type:                 exitcode-stdio-1.0
    default-language:     Haskell2010
    hs-source-dirs:       test/hspec
    ghc-options:          -Wall
    main-is:              Spec.hs
    build-depends:        base
                        , hspec >= 1.3
                        , QuickCheck
                        , helloworld
    other-modules:        MyLibSpec
    build-tool-depends:
        , hspec-discover:hspec-discover

Create test/hspec/Spec.hs specified as main-is in the cabal file.
```
{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
```

Write test code in test/hspec/MyLibSpec.hs. For testing, I targeted a function that takes two Int arguments and returns the result of adding them together.

module MyLibSpec (spec) where

import Test.Hspec
import MyLib

spec :: Spec
spec = do
    describe "`addInt` takes two arguments of Int and returns the result of adding them." $ do
        it "When give addInt 1 and 2 then return 3" $
            MyLib.addInt 1 2 `shouldBe` 3

Add the function to be tested in src/MyLib.hs.

module MyLib (someFunc, addInt) where

(省略)

addInt :: Int -> Int -> Int
addInt x y = x + y

Run tests with cabal test.

root@5499af50db5b:/workspace/projects/helloworld# cabal test; echo $?;
Build profile: -w ghc-9.4.4 -O1
In order, the following will be built (use -v for more details):
 - helloworld-0.1.0.0 (test:doctest) (first run)
 - helloworld-0.1.0.0 (test:helloworld-test) (first run)
 - helloworld-0.1.0.0 (test:spec) (first run)
Preprocessing test suite 'spec' for helloworld-0.1.0.0..
Preprocessing test suite 'doctest' for helloworld-0.1.0.0..
Preprocessing test suite 'helloworld-test' for helloworld-0.1.0.0..
Building test suite 'helloworld-test' for helloworld-0.1.0.0..
Building test suite 'doctest' for helloworld-0.1.0.0..
Building test suite 'spec' for helloworld-0.1.0.0..
Running 1 test suites...
Test suite helloworld-test: RUNNING...
Test suite helloworld-test: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/helloworld-test/test/helloworld-0.1.0.0-helloworld-test.log
1 of 1 test suites (1 of 1 test cases) passed.
Running 1 test suites...
Test suite doctest: RUNNING...
Running 1 test suites...
Test suite spec: RUNNING...
Test suite spec: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/spec/test/helloworld-0.1.0.0-spec.log
1 of 1 test suites (1 of 1 test cases) passed.
Test suite doctest: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/doctest/test/helloworld-0.1.0.0-doctest.log
1 of 1 test suites (1 of 1 test cases) passed.
0
root@5499af50db5b:/workspace/projects/helloworld#

The output when there is a NG in the test is as follows.

root@5499af50db5b:/workspace/projects/helloworld# cabal test; echo $?;
Build profile: -w ghc-9.4.4 -O1
In order, the following will be built (use -v for more details):
 - helloworld-0.1.0.0 (test:doctest) (first run)
 - helloworld-0.1.0.0 (test:helloworld-test) (first run)
 - helloworld-0.1.0.0 (test:spec) (file test/hspec/MyLibSpec.hs changed)
Preprocessing test suite 'doctest' for helloworld-0.1.0.0..
Preprocessing test suite 'helloworld-test' for helloworld-0.1.0.0..
Preprocessing test suite 'spec' for helloworld-0.1.0.0..
Building test suite 'doctest' for helloworld-0.1.0.0..
Building test suite 'helloworld-test' for helloworld-0.1.0.0..
Building test suite 'spec' for helloworld-0.1.0.0..
[1 of 2] Compiling MyLibSpec        ( test/hspec/MyLibSpec.hs, /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/spec/build/spec/spec-tmp/MyLibSpec.o ) [Source file changed]
Running 1 test suites...
Test suite helloworld-test: RUNNING...
[2 of 2] Compiling Main             ( test/hspec/Spec.hs, /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/spec/build/spec/spec-tmp/Main.o ) [MyLibSpec changed]
Test suite helloworld-test: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/helloworld-test/test/helloworld-0.1.0.0-helloworld-test.log
1 of 1 test suites (1 of 1 test cases) passed.
Running 1 test suites...
Test suite doctest: RUNNING...
[3 of 3] Linking /workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/spec/build/spec/spec [Objects changed]
Test suite doctest: PASS
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/doctest/test/helloworld-0.1.0.0-doctest.log
1 of 1 test suites (1 of 1 test cases) passed.
Running 1 test suites...
Test suite spec: RUNNING...

MyLib
  `addInt` takes two arguments of Int and returns the result of adding them.
    When give addInt 1 and 2 then return 3 [✘]

Failures:

  test/hspec/MyLibSpec.hs:10:30: 
  1) MyLib, `addInt` takes two arguments of Int and returns the result of adding them., When give addInt 1 and 2 then return 3
       expected: 2
        but got: 3

  To rerun use: --match "/MyLib/`addInt` takes two arguments of Int and returns the result of adding them./When give addInt 1 and 2 then return 3/"

Randomized with seed 1699898266

Finished in 0.0184 seconds
1 example, 1 failure

Test suite spec: FAIL
Test suite logged to:
/workspace/projects/helloworld/dist-newstyle/build/x86_64-linux/ghc-9.4.4/helloworld-0.1.0.0/t/spec/test/helloworld-0.1.0.0-spec.log
0 of 1 test suites (0 of 1 test cases) passed.
Error: cabal: Tests failed for test:spec from helloworld-0.1.0.0.

1
root@5499af50db5b:/workspace/projects/helloworld#

When I use underscores in the project name, project creation passes, but cabal test and cabal run fail. ↩

rhirano0715/haskell_x_docker_x_vscode

haskell_x_docker_x_vscode

Supplemental Environmental Description

Project Creation

Build and Run

Test

doctest

HSpec

Footnotes