Allow sbt-scoverage to work on windows

The -Xplugin option expects a classpath string with multiple paths
separated by a semicolon or colon depending on this operating system.
However, this currently always uses a colon, which doesn't work on
windows. This means scalac cannot find the scoverage plugin jars and
leads to errors about "bad options".

This modifies the -Xplugin logic to use File.pathSeparator when building
the Xplugin classpath, allowing it to work regardless of operating
system.

Also modifies excludedPackages when on windows to replace unix file
separators with escaped windows file separators. Modifies tests to
remove unnecessary escaping of unix separators.

Closes #440

.github/workflows/ci.yml

@@ -11,10 +11,11 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         java: [ '8', '17' ]
+        os: [ 'ubuntu-latest', 'windows-latest' ]
 
     steps:
       - name: checkout the repo

src/main/scala/scoverage/ScoverageSbtPlugin.scala

@@ -2,6 +2,7 @@ package scoverage
 
 import sbt.Keys._
 import sbt._
+import sbt.internal.util.Util.isWindows
 import sbt.plugins.JvmPlugin
 import scoverage.reporter.CoberturaXmlWriter
 import scoverage.domain.Constants
@@ -147,7 +148,7 @@ object ScoverageSbtPlugin extends AutoPlugin {
 
         Seq(
           Some(
-            s"-Xplugin:${pluginPaths.mkString(":")}"
+            s"-Xplugin:${pluginPaths.mkString(java.io.File.pathSeparator)}"
           ),
           Some(
             s"-P:scoverage:dataDir:${coverageDataDir.value.getAbsolutePath}/scoverage-data"
@@ -160,6 +161,7 @@ object ScoverageSbtPlugin extends AutoPlugin {
             .map(v => s"-P:scoverage:excludedPackages:$v"),
           Option(coverageExcludedFiles.value.trim)
             .filter(_.nonEmpty)
+            .map(v => if (isWindows) v.replace("/", "\\\\") else v) // replace unix file separators with escaped windows file separators
             .map(v => s"-P:scoverage:excludedFiles:$v"),
           Some("-P:scoverage:reportTestName"),
           // rangepos is broken in some releases of scala so option to turn it off

src/sbt-test/scoverage/coverage-excluded-files/build.sbt

@@ -4,7 +4,7 @@ scalaVersion := "2.13.6"
 
 libraryDependencies += "org.scalameta" %% "munit" % "0.7.29" % Test
 
-coverageExcludedFiles := ".*\\/two\\/GoodCoverage"
+coverageExcludedFiles := ".*/two/GoodCoverage"
 
 resolvers ++= {
   if (sys.props.get("plugin.version").exists(_.endsWith("-SNAPSHOT")))

src/sbt-test/scoverage/scala3-coverage-excluded-files/build.sbt

@@ -4,7 +4,7 @@ scalaVersion := "3.2.0-RC1"
 
 libraryDependencies += "org.scalameta" %% "munit" % "0.7.29" % Test
 
-coverageExcludedFiles := ".*\\/two\\/GoodCoverage"
+coverageExcludedFiles := ".*/two/GoodCoverage"
 
 resolvers ++= {
   if (sys.props.get("plugin.version").exists(_.endsWith("-SNAPSHOT")))