fix: Angle brackets no longer cause malformed html reports

src/main/scala/com/sksamuel/scapegoat/io/HtmlReportWriter.scala

@@ -2,7 +2,7 @@ package com.sksamuel.scapegoat.io
 
 import scala.xml.{Elem, Unparsed, XML}
 
-import com.sksamuel.scapegoat.{Feedback, Levels}
+import com.sksamuel.scapegoat.{Feedback, Levels, Warning}
 
 /**
  * @author
@@ -100,11 +100,11 @@ object HtmlReportWriter extends ReportWriter {
         {reporter.warnings(Levels.Warning).size.toString}
         Infos
         {reporter.warnings(Levels.Info).size.toString}
-      </h3>{warnings(reporter)}
+      </h3>{warnings(reporter.warningsWithMinimalLevel)}
     </body>
 
-  private def warnings(reporter: Feedback): Seq[Elem] = {
-    reporter.warningsWithMinimalLevel.map { warning =>
+  private[io] def warnings(warnings: Seq[Warning]): Seq[Elem] = {
+    warnings.map { warning =>
       val source = warning.sourceFileNormalized + ":" + warning.line
       <div class="warning">
           <div class="source">
@@ -123,7 +123,7 @@ object HtmlReportWriter extends ReportWriter {
           </span>
           </div>
           <div>
-            {decorateCode(warning.explanation)}
+            {decorateCode(warning.explanation.replace("<", "&lt;").replace(">", "&gt;"))}
           </div>{
         warning.snippet match {
           case None =>

src/test/scala/com/sksamuel/scapegoat/io/HtmlReportWriterTest.scala

@@ -0,0 +1,44 @@
+package com.sksamuel.scapegoat.io
+
+import org.scalatest.freespec.AnyFreeSpec
+import org.scalatest.matchers.should.Matchers
+import com.sksamuel.scapegoat.{Levels, Warning}
+
+class HtmlReportWriterTest extends AnyFreeSpec with Matchers {
+
+  "HtmlReportWriter" - {
+    "should escape angle brackets" in {
+      val warnings = Seq(
+        Warning(
+          "Pointless type bounds",
+          13,
+          Levels.Error,
+          "/home/johnnei/git/scapegoat/src/main/scala/com/sksamuel/File.scala",
+          "com.sksamuel.File.scala",
+          None,
+          explanation = "Finds type bounds of the form `A <: Any` or `A >: Nothing`.",
+          inspection = "com.sksamuel.scapegoat.inspections.inference.PointlessTypeBounds"
+        )
+      )
+
+      val escapedReport = Seq(
+        <div class="warning">
+          <div class="source">
+            com.sksamuel.File.scala:13
+          </div>
+          <div class="title">
+            <span class="label label-danger">Error</span>&nbsp;<span>Pointless type bounds</span>&nbsp; <span class="inspection">
+            com.sksamuel.scapegoat.inspections.inference.PointlessTypeBounds
+          </span>
+          </div>
+          <div>
+            <span>Finds type bounds of the form <code>A &lt;: Any</code> or <code>A &gt;: Nothing</code>.</span>
+          </div>
+        </div>
+      )
+
+      val report = HtmlReportWriter.warnings(warnings)
+      report.toString() shouldEqual escapedReport.toString()
+    }
+  }
+}