Merge pull request #1192 from eed3si9n/wip/dependency-tree

Document dependencyTree

src/reference/SUMMARY.md

@@ -12,6 +12,7 @@
   - [Working with an existing build](guide/running.md)
   - [Build definition basics](guide/build-definition-basics.md)
   - [Library dependency basics](guide/library-dependency-basics.md)
+  - [Multi project basics](guide/multi-project-basics.md)
   - [Build layout](guide/build-layout.md)
   - [sbt with IDEs](guide/IDE.md)
 - [sbt Reference]()

src/reference/guide/06-Task-Graph.md

@@ -234,6 +234,30 @@ In this way, all build dependencies in sbt are *automatic* rather than
 explicitly declared. If you use a key's value in another computation,
 then the computation depends on that key.
 
+#### Defining a task that depends on other keys
+
+`scalacOptions` is a task key used for compiler options.
+Here's an example of appending a compiler option based on the `version` setting.
+
+```scala
+name := "hello"
+version := "0.1.0-SNAPSHOT"
+Compile / scalacOptions += {
+  val v = version.value
+  s"-Dversion=$v"
+}
+```
+
+Here's how it should look on the sbt shell:
+
+```
+sbt:bar> show Compile/scalacOptions
+[info] * -Dversion=0.1.0-SNAPSHOT
+```
+
+This demonstrates that the right-hand side doesn't just take
+hard-coded string values.
+
 #### Defining a task that depends on other settings
 
 `scalacOptions` is a task key.

src/reference/guide/library-dependency-basics.md

@@ -87,3 +87,26 @@ name := "something"
 libraryDependencies += toolkit
 libraryDependencies += toolkitTest % Test
 ```
+
+Viewing library dependencies
+----------------------------
+
+Type in `Compile/dependencyTree` in the sbt shell to show the library dependency tree, including the transitive dependencies:
+
+```
+> Compile/dependencyTree
+```
+
+This should display something like the following:
+
+```
+sbt:bar> Compile/dependencyTree
+[info] default:bar_3:0.1.0-SNAPSHOT
+[info]   +-org.scala-lang:scala3-library_3:3.3.1 [S]
+[info]   +-org.scala-lang:toolkit_3:0.2.0
+[info]     +-com.lihaoyi:os-lib_3:0.9.1
+[info]     | +-com.lihaoyi:geny_3:1.0.0
+[info]     | | +-org.scala-lang:scala3-library_3:3.1.3 (evicted by: 3.3.1)
+[info]     | | +-org.scala-lang:scala3-library_3:3.3.1 [S]
+....
+```

src/reference/guide/multi-project-basics.md

@@ -0,0 +1,36 @@
+
+  [Basic-Def]: Basic-Def.html
+  [Scopes]: Scopes.html
+  [Directories]: Directories.html
+  [Organizing-Build]: Organizing-Build.html
+
+Multi project basics
+====================
+
+While a simple program can start out as a single-project build,
+it's more common for a build to split into smaller, multiple subprojects.
+
+Each subproject in a build has its own source directories, generates
+its own JAR file when you run `packageBin`, and in general works like any
+other project.
+
+A project is defined by declaring a lazy val of type
+[Project](../../api/sbt/Project.html). For example, :
+
+```scala
+scalaVersion := "{{scala3_example_version}}"
+
+lazy val core = (project in file("core"))
+  .settings(
+    name := "core",
+  )
+
+lazy val util = (project in file("util"))
+  .dependsOn(core)
+  .settings(
+    name := "util",
+  )
+```
+
+The name of the val is used as the subproject's ID, which
+is used to refer to the subproject at the sbt shell.