Sbt子项目中testOnly（Scalatest）命令无法执行问题

It looks like your some-service subproject doesn’t have the necessary setup to recognize the testOnly command. Here are the most likely fixes to resolve this issue:

1. Ensure the Subproject Inherits Test Settings #

Your root project uses Commons.settings, but if your some-service subproject isn’t explicitly including these settings, it won’t have access to test-related commands like testOnly. Update your project definition to apply the common settings to the subproject:

lazy val `some-service` = (project in file("some-service"))
  .settings(Commons.settings: _*) // Add this line to inherit test configurations

2. Verify ScalaTest Dependencies & Plugin Are Configured #

The testOnly command is provided by ScalaTest, so make sure your build includes the required dependencies and plugin:

In project/plugins.sbt: #

Add the ScalaTest sbt plugin to enable test commands:

addSbtPlugin("org.scalatest" % "scalatest-sbt-plugin" % "3.2.15") // Use the latest compatible version

In your Commons.settings (typically in Build.scala or build.sbt): #

Include the ScalaTest dependency in the Test scope:

lazy val Commons = Seq(
  // ... other shared settings ...
  libraryDependencies += "org.scalatest" %% "scalatest" % "3.2.15" % Test
)

3. Double-Check the testOnly Command Syntax #

Once the setup is correct, ensure you’re using the right syntax after switching to the subproject:

project some-service
testOnly *MyTest

The asterisk (*) acts as a wildcard—if your test lives in a package, you might need to use something like testOnly com.example.*MyTest to match it properly.

4. Reload sbt After Changes #

After updating your build files, run reload in the sbt shell to apply the new configuration. Then try the testOnly command again.

内容的提问来源于stack exchange，提问作者FrancMo