Sbt 在文件中或在多项目中的 commonSettings 中放置设置有啥区别

Posted 2023-03-24

【中文标题】Sbt 在文件中或在多项目中的 commonSettings 中放置设置有啥区别

【英文标题】：Sbt what is the difference placing settings in the file or in commonSettings in multi projectSbt 在文件中或在多项目中的 commonSettings 中放置设置有什么区别

【发布时间】：2019-06-22 08:27:52

【问题描述】：

初学者的问题，我有一个多项目的sbt文件，如果我把通用设置放在文件的开头有什么区别吗？例如：

organization := "com.example"
  version := "0.0.1-SNAPSHOT"
  scalaVersion := "2.11.12"
resolvers ++= Seq(
    "Apache Development Snapshot Repository" at "https://repository.apache.org/content/repositories/snapshots/",
    "Typesafe repository" at "http://repo.typesafe.com/typesafe/releases/",

    Resolver.mavenLocal
  )
assemblyMergeStrategy in assembly := 
    case PathList("META-INF", xs @ _*) => MergeStrategy.discard
    case x => MergeStrategy.first
  
lazy val commonSettings  = Seq(  libraryDependencies ++= commonDependencies ++ testingDependencies)
lazy val sharedProject = (project in file(...))
.settings(commonSettings: _*)
val projectA = .....dependsOn(sharedPorject)
val projectB = .....dependsOn(sharedPorject)

或者如果我把它放在通用设置中

lazy val commonSettings  = Seq(  
organization := "com.example",
  version := "0.0.1-SNAPSHOT",
  scalaVersion := "2.11.12",
resolvers ++= Seq(
    "Apache Development Snapshot Repository" at "https://repository.apache.org/content/repositories/snapshots/",
    "Typesafe repository" at "http://repo.typesafe.com/typesafe/releases/",
    Resolver.mavenLocal
  ),
assemblyMergeStrategy in assembly := 
    case PathList("META-INF", xs @ _*) => MergeStrategy.discard
    case x => MergeStrategy.first
  ,
libraryDependencies ++= commonDependencies ++ testingDependencies)
lazy val sharedProject = (project in file(...))
.settings(commonSettings: _*)
val projectA = .....dependsOn(sharedPorject)
val projectB = .....dependsOn(sharedPorject)

有什么区别？

【参考方案1】：

任何未附加到特定项目设置的设置，即.settings()，都附加到根项目。

这样的代码

organization := "foo"

与

相同

lazy val root = (project in file(".")).settings(organization := "foo")

现在，如果您定义了一个新的子项目，例如 common 并将 organization 添加到其中

lazy val common = (project in file("common")).settings(organization := "bar")

只有它的值organization 设置为bar。

当根项目也定义了自己的organization 时，这将在示例中成立。

lazy val root = (project in file(".")).settings(organization := "foo")

lazy val common = (project in file("common")).settings(organization := "bar")

这很容易使用命令sbt "show organization" 和sbt "show common/organization" 进行测试。它将分别打印foo 和bar。

最后，如果您想为所有子项目定义相同的值，请在根项目中为范围 ThisBuild 添加设置，如下例所示：

organization in ThisBuild := "foo"

lazy val common = (project in file("common")).settings(???)

或将设置存储在Seq 中并将其应用于所有子项目和根目录。这将具有与ThisBuild 范围内类似的效果，但更明确：

val commonSettings = Seq(organization := "foo")

lazy val root = (project in file(".")).settings(commonSettings)
lazy val common = (project in file("common")).settings(commonSettings)