找不到模块“Test.HUnit”

Question

我全新安装了 stack 和 ghci:

$ stack --version

Version 1.6.3, Git revision b27e629b8c4ce369e3b8273f04db193b060000db (5454 commits) x86_64 hpack-0.20.0

$ ghci --version

The Glorious Glasgow Haskell Compilation System, version 8.2.1

我做了一个新项目：

$ stack new so-mve

Downloading template "new-template" to create project "so-mve" in so-mve/ 
... blah blah blah ...
Looking for .cabal or package.yaml files to use to init the project.
Using cabal packages:
- so-mve/
Selecting the best among 12 snapshots...
* Matches lts-10.3
Selected resolver: lts-10.3
Initialising configuration using resolver: lts-10.3
Total number of user packages considered: 1
Writing configuration to file: so-mve/stack.yaml
All done.

看起来不错：

$ tree so-mve

so-mve
├── ChangeLog.md
├── LICENSE
├── README.md
├── Setup.hs
├── app
│   └── Main.hs
├── package.yaml
├── so-mve.cabal
├── src
│   └── Lib.hs
├── stack.yaml
└── test
    └── Spec.hs

它构建并且运行s:

$ cd so-mve
$ stack build

so-mve-0.1.0.0: build (lib + exe)
Preprocessing library for so-mve-0.1.0.0..
Building library for so-mve-0.1.0.0..
Preprocessing executable 'so-mve-exe' for so-mve-0.1.0.0..
Building executable 'so-mve-exe' for so-mve-0.1.0.0..
so-mve-0.1.0.0: copy/register
Installing library in /...blah-blah.../so-mve/.stack-work/install/x86_64-osx/lts-10.3/8.2.2/lib/x86_64-osx-ghc-8.2.2/so-mve-0.1.0.0-5kG2WnHWwo99IiYYGoxrcC
Installing executable so-mve-exe in /...blah-blah.../so-mve/.stack-work/install/x86_64-osx/lts-10.3/8.2.2/bin
Registering library for so-mve-0.1.0.0..

$ stack exec so-mve-exe

someFunc

测试运行：

$ stack test

blah blah blah
[2 of 2] Compiling Main             ( test/Spec.hs, .stack-work/dist/x86_64-osx/Cabal-2.0.1.0/build/so-mve-test/so-mve-test-tmp/Main.o )
...blah-blah-blah...
Progress: 1/2Test suite not yet implemented
so-mve-0.1.0.0: Test suite so-mve-test passed
Completed 2 action(s).

我三次检查 HUnit 是否已安装

$ stack install HUnit

Populated index cache.

我在test/Spec.hs

中加一行

$ cat test/Spec.hs

import Test.HUnit
main :: IO ()
main = putStrLn "Test suite not yet implemented"

无效：

$ stack test

so-mve-0.1.0.0: unregistering (components added: test:so-mve-test)
so-mve-0.1.0.0: build (lib + exe + test)
Preprocessing library for so-mve-0.1.0.0..
Building library for so-mve-0.1.0.0..
Preprocessing executable 'so-mve-exe' for so-mve-0.1.0.0..
Building executable 'so-mve-exe' for so-mve-0.1.0.0..
Preprocessing test suite 'so-mve-test' for so-mve-0.1.0.0..
Building test suite 'so-mve-test' for so-mve-0.1.0.0..
[2 of 2] Compiling Main             ( test/Spec.hs, .stack-work/dist/x86_64-osx/Cabal-2.0.1.0/build/so-mve-test/so-mve-test-tmp/Main.o )

/...blah-blah.../so-mve/test/Spec.hs:1:1: error:
    Could not find module ‘Test.HUnit’
    Use -v to see a list of the files searched for.
  |          
1 | import Test.HUnit
  | ^^^^^^^^^^^^^^^^^

Progress: 1/2
--  While building custom Setup.hs for package so-mve-0.1.0.0 using:
      /Users/XXXXXXXX/.stack/setup-exe-cache/x86_64-osx/Cabal-simple_mPHDZzAJ_2.0.1.0_ghc-8.2.2 --builddir=.stack-work/dist/x86_64-osx/Cabal-2.0.1.0 build lib:so-mve exe:so-mve-exe test:so-mve-test --ghc-options " -ddump-hi -ddump-to-file -fdiagnostics-color=always"
    Process exited with code: ExitFailure 1

我在导入其他库时没有遇到问题，例如 Text.Read 和 Text.Printf。我用谷歌搜索了一堆，但没有找到答案。对我有什么想法吗？

Answer 1

您使用 stack 全局安装了 HUnit，但这并不意味着它是。

项目的 cabal 文件需要指定对 HUnit 的依赖：

--so-mve.cabal
...
test-suite so-mve 
  type:                exitcode-stdio-1.0
  hs-source-dirs:      test
  main-is:             Spec.hs
  build-depends:       base
                     , HUnit
  ...

Text.Read和Text.Printf都包含在base中，所以你不需要指定额外的依赖。

正如评论中所指出的那样，由于您使用的是 package.yaml（而不是 stack.yaml）配置以及较新版本的 stack，因此您需要在那里指定依赖项而不是 .cabal 文件：

tests:
  so-mve-test:
    main: Spec.hs
    source-dirs: test
    ghc-options:
    - -threaded
    dependencies:
    - HUnit

Answer 2

您只需将 HUnit 添加到测试项目的依赖项中。使用 stack 时，您应该编辑 package.yaml 文件以指定依赖项。特别是，您的测试配置应该类似于：

tests:
  so-mve-test:
    main:                Spec.hs
    source-dirs:         test
    ghc-options:
    - ...
    dependencies:
    - HUnit

这在最新的 Stack Guide, under the section Adding Dependencies 中有记载。

找不到模块“Test.HUnit”

Could not find module ‘Test.HUnit’

haskell

haskell-stack