如何使用 VS Code 和 Metals 运行现有的 Scala 项目？

Question

我是 Scala 的新手，我发现 Scala IDE 在我的机器上对于搜索代码库和编辑代码等基本操作非常慢。我习惯了 Visual Studio Code，很高兴找到this metals extension。

我能够“导入构建”并解决问题，例如在我的项目中提高 scala 版本，但我不确定如何重现此步骤以设置运行配置并在 Scala IDE 中实际启动我们的应用程序。

我们有一个父文件夹，其中包含一堆项目和一个“consoleapp”项目，这是我们应用程序的主要入口点 - 它导入所有其他项目的逻辑/路由。

|____parent
| |____consoleapp
| |____project1
| |____project2 

我在 consoleapp 文件夹和父文件夹中尝试了 sbt run 和 sbt runMain consoleapp，但它们不起作用。

我不确定我们的设置中还有哪些其他信息是相关的 - 很高兴根据需要提供更多信息。

更新以在下面添加更多详细信息：

consoleapp/build.sbt

name := "consoleapp"

version := "1.0"

scalaVersion := "2.12.10"

packMain := Map("consoleapp" -> "consoleapp")

libraryDependencies ++=  Seq (...)

我运行的命令的输出 - sbt run 和 sbt runMain

从 ~/scala/parent 运行

> sbt run                                                                                                                                                                 masterstate [0a8dab85] modified
[info] Loading settings for project global-plugins from metals.sbt,build.sbt ...
[info] Loading global plugins from /Users/pradhyo/.sbt/1.0/plugins
[info] Loading project definition from /Users/pradhyo/scala/parent/project
[info] Loading settings for project consoleapp from build.sbt ...
... 
Loading settings for all other projects in parent folder
...
[info] Loading settings for project parent from build.sbt ...
[info] Resolving key references (22435 settings) ...
[info] Set current project to parent (in build file:/Users/pradhyo/scala/parent/)
[error] java.lang.RuntimeException: No main class detected.
[error]     at scala.sys.package$.error(package.scala:30)
[error] stack trace is suppressed; run last Compile / bgRun for the full output
[error] (Compile / bgRun) No main class detected.
[error] Total time: 1 s, completed 18-Dec-2019 1:41:25 PM

从 ~/scala/parent 运行

> sbt "runMain consoleapp.consoleapp"                                                                                                                                     masterstate [0a8dab85] modified
[info] Loading settings for project global-plugins from metals.sbt,build.sbt ...
[info] Loading global plugins from /Users/pradhyo/.sbt/1.0/plugins
[info] Loading project definition from /Users/pradhyo/scala/parent/project
[info] Loading settings for project consoleapp from build.sbt ...
... 
Loading settings for all other projects in parent folder
...
[info] Loading settings for project parent from build.sbt ...
[info] Resolving key references (22435 settings) ...
[info] Set current project to parent (in build file:/Users/pradhyo/scala/parent/)
[info] running consoleapp.consoleapp 
[error] (run-main-0) java.lang.ClassNotFoundException: consoleapp.consoleapp
[error] java.lang.ClassNotFoundException: consoleapp.consoleapp
[error]     at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
[error] stack trace is suppressed; run last Compile / bgRunMain for the full output
[error] Nonzero exit code: 1
[error] (Compile / runMain) Nonzero exit code: 1
[error] Total time: 0 s, completed 18-Dec-2019 1:46:21 PM

从 ~/scala/parent/consoleapp 运行

> sbt run                                                                                                                                                                 masterstate [0a8dab85] modified
[info] Loading settings for project global-plugins from metals.sbt,build.sbt ...
[info] Loading global plugins from /Users/pradhyo/.sbt/1.0/plugins
[info] Loading project definition from /Users/pradhyo/scala/parent/consoleapp/project
[info] Loading settings for project consoleapp from build.sbt ...
[info] Set current project to consoleapp (in build file:/Users/pradhyo/scala/parent/consoleapp/)
[error] java.lang.RuntimeException: No main class detected.
[error]     at scala.sys.package$.error(package.scala:30)
[error] stack trace is suppressed; run last Compile / bgRun for the full output
[error] (Compile / bgRun) No main class detected.
[error] Total time: 0 s, completed 18-Dec-2019 1:49:26 PM

从 ~/scala/parent/consoleapp 运行

> sbt "runMain consoleapp"                                                                                                                                                masterstate [0a8dab85] modified
[info] Loading settings for project global-plugins from metals.sbt,build.sbt ...
[info] Loading global plugins from /Users/pradhyo/.sbt/1.0/plugins
[info] Loading project definition from /Users/pradhyo/scala/parent/consoleapp/project
[info] Loading settings for project consoleapp from build.sbt ...
[info] Set current project to consoleapp (in build file:/Users/pradhyo/scala/parent/consoleapp/)
[info] running consoleapp 
[error] (run-main-0) java.lang.ClassNotFoundException: consoleapp
[error] java.lang.ClassNotFoundException: consoleapp
[error]     at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
[error] stack trace is suppressed; run last Compile / bgRunMain for the full output
[error] Nonzero exit code: 1
[error] (Compile / runMain) Nonzero exit code: 1
[error] Total time: 1 s, completed 18-Dec-2019 1:50:06 PM

Answer 1

按照Scala Metals VSCode Readme 中的说明操作后，对问题中的 Eclipse 屏幕截图使用与此类似的启动配置。

.vscode/launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "scala",
            "name": "Debug consoleapp",
            "request": "launch",
            "mainClass": "consoleapp",
            "buildTarget": "consoleapp",
            "args": [],
            "jvmOptions": ["-J-Dconfig.file=/path/to/config/file"]
        }
    ]
}

我无法正确传递pureconfig 的配置文件。这是the Github issue 与正确的jvmOptions 行。

Answer 2

Metals 支持这些 Scala 版本 2.13.0、2.13.1、2.12.8、2.12.9、 2.12.10、2.12.7 和 2.11.12

这是我从他们的文档中注意到的 (doc)。因此，它可以查明我在 cmets 中解决的您和我的问题。

您的scalaVersion := "2.12.3" 未在此处列出。