Add an option to execute the plugin with a custom encoding setting

README.md

@@ -43,6 +43,7 @@ You can configure output generated by `gradle reportScoverage` using flags:
 | coverageOutputXML       | true          | Enables/disables scoverage XML output.          |
 | coverageOutputHTML      | true          | Enables/disables scoverage HTML output.         |
 | coverageDebug           | false         | Enables/disables scoverage debug output.        |
+| encoding                | null          | Sets encoding (otherwise uses system default).  |
 
 Aggregating Reports
 -------------------
@@ -97,3 +98,22 @@ checkScoverage {
     minimumRate = 0.5
 }
 ```
+
+Troubleshooting
+--------------
+
+### Encoding
+
+You may encounter the following exceptions when executing the `reportScoverage` task:
+
+```text
+Exception in thread "main" java.nio.charset.UnmappableCharacterException: Input length = 1
+
+Exception in thread "main" java.nio.charset.MalformedInputException: Input length = 1
+```
+
+There is a good chance that this is a problem with encoding. You could try and resolve these by configuring the encoding
+to the encoding of you sources. For example:
+```groovy
+scoverage.encoding = "UTF-8"
+```  

src/main/groovy/org/scoverage/ScoverageAggregate.groovy

@@ -12,6 +12,9 @@ class ScoverageAggregate extends JavaExec {
         def extension = ScoveragePlugin.extensionIn(project)
         setClasspath(ScoveragePlugin.extensionIn(project).pluginClasspath)
         setMain('org.scoverage.AggregateReportApp')
+        if (extension.encoding) {
+            jvmArgs("-Dfile.encoding=$extension.encoding")
+        }
         def reportPath = reportDirOrDefault()
         setArgs([
             project.projectDir,

src/main/groovy/org/scoverage/ScoverageExtension.groovy

@@ -9,7 +9,9 @@ import org.gradle.api.plugins.JavaPlugin
 import org.gradle.api.plugins.scala.ScalaPlugin
 import org.gradle.api.tasks.SourceSet
 import org.gradle.api.tasks.bundling.Jar
+import org.gradle.api.tasks.scala.ScalaCompile
 import org.gradle.api.tasks.testing.Test
+import org.gradle.language.scala.tasks.AbstractScalaCompile
 import org.gradle.util.GFileUtils
 
 import java.util.concurrent.Callable
@@ -33,6 +35,8 @@ class ScoverageExtension {
     List<String> excludedPackages = []
     /** regex for each excluded file */
     List<String> excludedFiles = []
+    /** Custom encoding to run the report application with */
+    String encoding
 
     FileCollection pluginClasspath
 
@@ -146,10 +150,23 @@ class ScoverageExtension {
                 if (extension.highlighting) {
                     parameters.add('-Yrangepos')
                 }
+                if (extension.encoding) {
+                    parameters.add("-Dfile.encoding=$extension.encoding".toString())
+                }
                 doFirst {
                     GFileUtils.deleteDirectory(destinationDir)
                 }
                 scalaCompileOptions.additionalParameters = parameters
+
+                if (extension.encoding) {
+                    List<String> forkOptions = ["-Dfile.encoding=$extension.encoding".toString()]
+                    List<String> existingForkOptions = scalaCompileOptions.forkOptions.jvmArgs
+                    if (existingForkOptions) {
+                        forkOptions.addAll(existingForkOptions)
+                    }
+                    scalaCompileOptions.forkOptions.jvmArgs = forkOptions
+                }
+
                 // the compile task creates a store of measured statements
                 outputs.file(new File(extension.dataDir, 'scoverage.coverage.xml'))
             }

src/main/groovy/org/scoverage/ScoverageReport.groovy

@@ -10,6 +10,9 @@ class ScoverageReport extends JavaExec {
         extension.reportDir.mkdirs()
         setClasspath(extension.pluginClasspath)
         setMain('org.scoverage.SingleReportApp')
+        if (extension.encoding) {
+            jvmArgs("-Dfile.encoding=$extension.encoding")
+        }
         setArgs([
             /* sourceDir = */ extension.sources.absolutePath,
             /* dataDir = */ extension.dataDir.absolutePath,