Use tag or branch name.

invert-gradle-plugin/src/main/kotlin/com/squareup/invert/internal/GitDataCollector.kt

@@ -54,6 +54,19 @@ internal class GitDataCollector(private val gitProjectRootDir: File) {
     return exec("git rev-parse --abbrev-ref HEAD", gitProjectRootDir).stdOut.lines()[0]
   }
 
+  fun currentTag(): GitBranch? {
+    val cmdResult = exec("git describe --tags --exact-match", gitProjectRootDir).stdOut.lines()[0]
+    return if (cmdResult.contains("fatal: no tag exactly matches")) {
+      null
+    } else {
+      cmdResult
+    }
+  }
+
+  fun currentBranchOrTag(): GitBranch {
+    return currentTag() ?: currentBranch()
+  }
+
   /**
    *
    * Example output of the command is:

invert-gradle-plugin/src/main/kotlin/com/squareup/invert/internal/report/InvertReportWriter.kt

@@ -44,10 +44,10 @@ class InvertReportWriter(
 
     val globalStats = computeGlobalTotals(allProjectsStatsData, collectedOwnershipInfo)
 
-    val historicalDataWithCurrent = historicalData + HistoricalData(
+    val historicalDataWithCurrent = (historicalData + HistoricalData(
       reportMetadata = reportMetadata,
       statTotalsAndMetadata = CollectedStatTotalsJsReportModel(globalStats)
-    )
+    )).sortedBy { it.reportMetadata.latestCommitTime  }
 
     // JSON Report
     InvertJsonReportWriter(invertLogger, rootBuildReportsDir).createInvertJsonReport(

invert-gradle-plugin/src/main/kotlin/com/squareup/invert/internal/tasks/ProjectMetadataCollector.kt

@@ -27,7 +27,7 @@ object ProjectMetadataCollector {
       .withZone(TimeZone.getTimeZone(timeZoneId).toZoneId())
 
     val gitDataCollector = GitDataCollector(gitProjectDir)
-    val currentBranch: GitBranch = gitDataCollector.currentBranch()
+    val currentBranch: GitBranch = gitDataCollector.currentBranchOrTag()
     val currentBranchHash = gitDataCollector.gitShaOfBranch(currentBranch, logger)
 
     val latestCommitTimestamp = gitDataCollector.latestCommitTimestamp()