Adding gitMergeFrom and gitFilesChangedLastCommit

src/main/scala/com/github/sbt/git/ConsoleGitReadableOnly.scala

@@ -24,4 +24,10 @@ class ConsoleGitReadableOnly(git: GitRunner, cwd: File, log: Logger) extends Git
   def remoteOrigin: String = git("ls-remote", "--get-url", "origin")(cwd, log)
 
   def headCommitMessage: Option[String] = Try(git("log", "--pretty=%s\n\n%b", "-n", "1")(cwd, log)).toOption
+
+  def changedFiles: Seq[String] =
+    headCommitSha
+      .flatMap(headCommit => Try(git("diff-tree", "--no-commit-id", "--name-only", "-r", headCommit)(cwd, log)).toOption)
+      .map(_.split('\n').map(_.trim).toSeq)
+      .getOrElse(Seq.empty)
 }

src/main/scala/com/github/sbt/git/GitPlugin.scala

@@ -19,6 +19,9 @@ object SbtGit {
     val gitHeadCommitDate = SettingKey[Option[String]]("git-head-commit-date", "The commit date for the top commit of this project in ISO-8601 format.")
     val gitDescribedVersion = SettingKey[Option[String]]("git-described-version", "Version as returned by `git describe --tags`.")
     val gitUncommittedChanges = SettingKey[Boolean]("git-uncommitted-changes", "Whether there are uncommitted changes.")
+    val gitMergeMessagePatterns = settingKey[Seq[String]]("Collection of regex patterns with one sub-group to parse commit messages of merge commits")
+    val gitMergeFrom = SettingKey[Option[String]]("git-merge-from", "Possible name of a branch HEAD is a merge from")
+    val gitFilesChangedLastCommit = SettingKey[Seq[String]]("git-last-changes", "List of files changed in the last commit")
 
     // A Mechanism to run Git directly.
     val gitRunner = TaskKey[GitRunner]("git-runner", "The mechanism used to run git in the current build.")
@@ -124,6 +127,22 @@ object SbtGit {
     gitCurrentTags := gitReader.value.withGit(_.currentTags),
     gitCurrentBranch := Option(gitReader.value.withGit(_.branch)).getOrElse(""),
     ThisBuild / gitUncommittedChanges := gitReader.value.withGit(_.hasUncommittedChanges),
+    gitMergeMessagePatterns := Seq.empty[String],
+    gitFilesChangedLastCommit := gitReader.value.withGit(_.changedFiles),
+    gitMergeFrom := {
+      for {
+        headMessage <- gitHeadMessage.value.map(_.trim)
+        mergedFrom <- gitMergeMessagePatterns.value
+          .map(_.r.unanchored)
+          .flatMap { regex =>
+            headMessage match {
+              case regex(branch) => Option(branch)
+              case _ => None
+            }
+          }
+          .headOption
+      } yield mergedFrom
+    },
     scmInfo := parseScmInfo(gitReader.value.withGit(_.remoteOrigin))
   )
   private[sbt] def parseScmInfo(remoteOrigin: String): Option[ScmInfo] = {
@@ -260,6 +279,9 @@ object SbtGit {
     val baseVersion = ThisBuild / GitKeys.baseVersion
     val versionProperty = ThisBuild / GitKeys.versionProperty
     val gitUncommittedChanges = ThisBuild / GitKeys.gitUncommittedChanges
+    val gitFilesChangedLastCommit = ThisBuild / GitKeys.gitFilesChangedLastCommit
+    val gitMergeFrom = ThisBuild / GitKeys.gitMergeFrom
+    val gitMergeMessagePatterns = ThisBuild / GitKeys.gitMergeMessagePatterns
     val uncommittedSignifier = ThisBuild / GitKeys.uncommittedSignifier
     val formattedShaVersion = ThisBuild / GitKeys.formattedShaVersion
     val formattedDateVersion = ThisBuild / GitKeys.formattedDateVersion

src/main/scala/com/github/sbt/git/JGit.scala

@@ -2,16 +2,18 @@ package com.github.sbt.git
 
 import org.eclipse.jgit.lib.Repository
 import org.eclipse.jgit.storage.file.FileRepositoryBuilder
-import org.eclipse.jgit.api.{Git => PGit}
-import java.io.File
+import org.eclipse.jgit.api.Git as PGit
+import org.eclipse.jgit.diff.DiffFormatter
+
+import java.io.{ByteArrayOutputStream, File}
 import java.text.SimpleDateFormat
 import java.util.Date
-
 import org.eclipse.jgit.lib.ObjectId
 import org.eclipse.jgit.lib.Ref
 import org.eclipse.jgit.revwalk.{RevCommit, RevWalk}
 
 import scala.util.Try
+import scala.collection.JavaConverters.*
 
 
 // TODO - This class needs a bit more work, but at least it lets us use porcelain and wrap some higher-level
@@ -29,12 +31,10 @@ final class JGit(val repo: Repository) extends GitReadonlyInterface {
   def branch: String = repo.getBranch
 
   private def branchesRef: Seq[Ref] = {
-    import collection.JavaConverters._
     porcelain.branchList.call.asScala
   }
 
   def tags: Seq[Ref] = {
-    import collection.JavaConverters._
     porcelain.tagList.call().asScala
   }
 
@@ -96,14 +96,12 @@ final class JGit(val repo: Repository) extends GitReadonlyInterface {
   override def branches: Seq[String] = branchesRef.filter(_.getName.startsWith("refs/heads")).map(_.getName.drop(11))
 
   override def remoteBranches: Seq[String] = {
-    import collection.JavaConverters._
     import org.eclipse.jgit.api.ListBranchCommand.ListMode
     porcelain.branchList.setListMode(ListMode.REMOTE).call.asScala.filter(_.getName.startsWith("refs/remotes")).map(_.getName.drop(13))
   }
 
   override def remoteOrigin: String = {
     // same functionality as Process("git ls-remote --get-url origin").lines_!.head
-    import collection.JavaConverters._
     porcelain.remoteList().call.asScala
       .filter(_.getName == "origin")
       .flatMap(_.getURIs.asScala)
@@ -125,6 +123,24 @@ final class JGit(val repo: Repository) extends GitReadonlyInterface {
       format.format(new Date(millis))
     }
   }
+
+  /** Files changed in current commit *   */
+  override def changedFiles: Seq[String] = {
+    val walk = new RevWalk(repo)
+    val maybeChanges = for {
+      head <- headCommit.map(walk.parseCommit)
+      parent <- Try(head.getParent(0)).toOption
+    } yield {
+      val os = new ByteArrayOutputStream()
+      val diffFormatter = new DiffFormatter(os)
+      diffFormatter.setRepository(repo)
+      diffFormatter.scan(parent, head)
+        .asScala
+        .flatMap(entry => Set(entry.getOldPath, entry.getNewPath))
+        .filterNot(_.startsWith("/"))
+    }
+    maybeChanges.getOrElse(Seq.empty)
+  }
 }
 
 object JGit {

src/main/scala/com/github/sbt/git/ReadableGit.scala

@@ -28,6 +28,8 @@ trait GitReadonlyInterface {
   def remoteOrigin: String
   /** The message of current commit **/
   def headCommitMessage: Option[String]
+  /** Files changed in current commit **/
+  def changedFiles: Seq[String]
 }
 
 

src/sbt-test/git-plugin/files-changed/changes/build.sbt

@@ -0,0 +1,16 @@
+def proj(name: String) = Project(name, file(name)).enablePlugins(GitVersioning)
+
+
+lazy val a = proj("a")
+lazy val b = proj("b")
+
+enablePlugins(GitVersioning)
+
+git.baseVersion := "1.0"
+git.versionProperty := "DUMMY_BUILD_VERSION"
+
+val checkChangedFiles = taskKey[Unit]("checks the files changed in the last commit")
+checkChangedFiles := {
+  val value = git.gitFilesChangedLastCommit.value
+  assert(value sameElements Seq("README2.md", "README3.md"), s"changed files should return 2 entries, got $value")
+}

src/sbt-test/git-plugin/files-changed/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.github.sbt" % "sbt-git" % sys.props("project.version"))

src/sbt-test/git-plugin/files-changed/test

@@ -0,0 +1,11 @@
+> git init
+> git config user.email "[email protected]"
+> git config user.name "Tester"
+> git add README.md
+> git commit -m "test"
+> git add README2.md
+> git add README3.md
+> git commit -m "test2"
+$ copy-file changes/build.sbt build.sbt
+> reload
+> checkChangedFiles

src/sbt-test/git-plugin/merged-from/changes/build.sbt

@@ -0,0 +1,19 @@
+def proj(name: String) = Project(name, file(name)).enablePlugins(GitVersioning)
+
+
+lazy val a = proj("a")
+lazy val b = proj("b")
+
+enablePlugins(GitVersioning)
+
+git.baseVersion := "1.0"
+git.versionProperty := "DUMMY_BUILD_VERSION"
+git.gitMergeMessagePatterns := Seq(
+  raw"Merge branch '(.*?)'"
+)
+
+val checkMergedFrom = taskKey[Unit]("checks the merged from branch is correct")
+checkMergedFrom := {
+  val value = git.gitMergeFrom.value
+  assert(value == Option("branch_2"), s"Merged from should return the correct branch, got $value")
+}

src/sbt-test/git-plugin/merged-from/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.github.sbt" % "sbt-git" % sys.props("project.version"))

src/sbt-test/git-plugin/merged-from/test

@@ -0,0 +1,15 @@
+> git init
+> git config user.email "[email protected]"
+> git config user.name "Tester"
+> git add README.md
+> git commit -m "test"
+> git checkout -b branch_2
+> git add README2.md
+> git commit -m "test2"
+> git checkout master
+> git add README3.md
+> git commit -m "test3"
+> git merge --no-edit branch_2
+$ copy-file changes/build.sbt build.sbt
+> reload
+> checkMergedFrom