自定义NIO文件系统无法通过SBT的测试任务加载 [英] Custom NIO filesystem doesn't load through SBT's test task

问题描述

为了进行测试，我使用内存中的NIO FileSystem实现( memoryfs ).我之前已经利用了它，并且似乎在例如Maven.

For testing, I'm using an in-memory NIO FileSystem implementaion ( memoryfs ). I've taken advantage of it before, and it seems to run fine through e.g. Maven.

但是，现在，在SBT项目中，不可能初始化新的FileSystem .

However, now, in an SBT project, it's impossible to initialize a new FileSystem.

这里是用于重现该问题的最小SBT配置:

Here's a minimal SBT configuration to reproduce the problem:

import sbt._
import Keys._

name := "testfs"
organization := "com.example
version := "0.1-SNAPSHOT"

scalaVersion := "2.11.6"

libraryDependencies ++= { 
  val scalaTestVersion = "2.2.5"
  Seq(
    "org.scalatest" %% "scalatest" % scalaTestVersion % "test",
    "org.mockito" %  "mockito-core" % "1.10.19" % "test",
    "de.pfabulist.lindwurm" %  "memoryfs" % "0.28.3"   % "test"
  )}

这是一个测试:

import de.pfabulist.lindwurm.memory.MemoryFSBuilder
import org.scalatest.{FlatSpec, MustMatchers}


class FsDummySpec extends FlatSpec with MustMatchers {

  it must "init the FS" in {
    new MemoryFSBuilder().watchService(true).name("testFs").build() //init here
  }
}

运行sbt test将导致:

[info] FsDummySpec:
[info] - must init the FS *** FAILED ***
[info]   java.nio.file.ProviderNotFoundException: Provider "memoryfs" not found
[info]   at java.nio.file.FileSystems.getFileSystem(FileSystems.java:224)
[info]   at de.pfabulist.kleinod.paths.Pathss.getOrCreate(Pathss.java:76)

这是东西:它应该可以正常运行.我的问题是:为什么以及如何解决?

Here's the thing: this should run without any problems. My question is: why, and how to fix it?

浏览自定义FS提供程序文档看起来SBT以某种方式使类路径混乱，但是很难说出原因.

Glancing over the custom FS provider docs it looks like SBT borks the classpath somehow, but its hard to say why.

注意:有趣的是，IntelliJ IDEA的测试运行程序似乎可以顺利运行，问题仅出在命令行中(在"SBT适当"中).

Note: interestingly enough, IntelliJ IDEA's test runner seems to work without a hitch, the problem is only on the command line (in "SBT proper").

推荐答案

openCage的评论提示了解决方案.

The comment by openCage hinted at the solution.

事实证明，自定义文件系统确实需要附加元素，即位于META-INF/services中的服务提供商定义文件.

It turns out custom file systems do require an additional element, i.e. a service provider definition file located in META-INF/services.

如果您使用自定义的NIO文件系统，则需要使该提供程序定义文件在测试类路径中可用.

最简单的方法可能只是派生测试VM，即将以下内容添加到您的build.sbt:

The simplest way is probably just to fork the test VM, i.e. add the following to your build.sbt:

fork in Test := true

这篇关于自定义NIO文件系统无法通过SBT的测试任务加载的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！