Feature: Task-level dependencies

[mratsim]

I'd like to use Quickcheck for testing but it seems like currently either it's listed as a full dependency and get pulled on user machine, or it's not listed and it cannot be run as a nimble task.

Can we also allow requires at the task level.

[mratsim]

Another use case: comparing against reference implementations/libraries. In my case a C++ wrapper that I rewrote in pure Nim.

[dom96]

Perhaps you could run nimble install ... in the task?

[mratsim]

I just tried, that unfortunately didn't work :/

  Executing task test_property_debug in /Users/<username>/Programming/Status/stint/stint.nimble
   Warning: Package 'stint' has an incorrect structure. The top level of the package source directory should contain at most one module, named 'stint.nim', but a file named 'io.nim' was found. This will be an error in the future.
      Hint: If this is the primary source file in the package, rename it to 'stint.nim'. If it's a source file required by the main module, or if it is one of several modules exposed by 'stint', then move it into a 'stint/' subdirectory. If it's a test file or otherwise not required to build thethe package 'stint.nim', prevent its installation by adding `skipFiles = @["io.nim"]` to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info.
Downloading https://github.com/alehander42/nim-quicktest using git
   Warning: Package 'quicktest' has an incorrect structure. The top level of the package source directory should contain at most one module, named 'quicktest.nim', but a file named 'js_lib.nim' was found. This will be an error in the future.
      Hint: If this is the primary source file in the package, rename it to 'quicktest.nim'. If it's a source file required by the main module, or if it is one of several modules exposed by 'quicktest', then move it into a 'quicktest/' subdirectory. If it's a test file or otherwise not required to build the the package 'quicktest.nim', prevent its installation by adding `skipFiles = @["js_lib.nim"]` to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info.
  Verifying dependencies for quicktest@0.18.0
      Info: Dependency on random@#head already satisfied
  Verifying dependencies for random@#head
      Info: Dependency on https://github.com/alehander42/breeze.git@>= 0.0.5 already satisfied
  Verifying dependencies for breeze@0.0.5
 Installing quicktest@0.18.0
    Prompt: quicktest@0.18.0 already exists. Overwrite? [y/N]
    Answer: y
   Success: quicktest installed successfully.
  Verifying dependencies for stint@0.0.1
  Compiling tests/property_based.nim (from package stint) using c backend
Hint: used config file '/Users/<username>/.choosenim/toolchains/nim-#devel/config/nim.cfg' [Conf]
Hint: system [Processing]
Hint: property_based [Processing]
Hint: stint [Processing]
...
Hint: tables [Processing]
Hint: termios [Processing]
property_based.nim(10, 32) Error: cannot open 'quicktest'
       Tip: 4 messages have been suppressed, use --verbose to show them.
     Error: Execution failed with exit code 256
        ... Command: "/Users/<username>/.nimble/bin/nim" c --noNimblePath "--define:mpint_test" "--out:./build/property_based" "--run" "--nimcache:"nimcache""  "tests/property_based.nim"

[dom96]

After discussion on IRC I am tempted to implement this instead of #464.

https://irclogs.nim-lang.org/20-08-2018.html#16:05:30

For the Nimgen use case:

before install:
  requires "nimgen"
  exec "nimgen ngen.cfg"

For the test use case:

task test:
  requires "quickcheck"
  exec "nim c -r tests/tester"

Unlike the global requires, a task-level requires will immediately install the specified dependencies when the task is being executed.

Note: If nimble c -r tests/tester is used instead, the compilation will fail since the .nimble file only specifies quickcheck in the test task. This is why the workaround failed for you @mratsim. Nimble needs to allow the c task to be executed directly instead of via exec to solve this :(.

[dom96]

Okay, so I need to be able to override the NimScript task template for this. As such I will postpone this until another release.