Add support for Scala 2.11

.travis.yml

@@ -12,9 +12,11 @@ jobs:
     # default stage is test
     - env: TEST="scalafmt"
       script: ./bin/scalafmt --test
-    - env: TEST="sbt test"
+    - env: TEST="Scala 2.12"
       script: sbt test plugin/scripted
-    - env: TEST="sbt test"
+    - env: TEST="Scala 2.11"
+      script: sbt ++2.11.12 test
+    - env: TEST="Java 11"
       script: sbt test plugin/scripted
       jdk: openjdk11
     - stage: release

build.sbt

@@ -1,6 +1,13 @@
+def scala212 = "2.12.8"
+def scala211 = "2.11.12"
 inThisBuild(
   List(
-    scalaVersion := "2.12.8",
+    scalaVersion := scala212,
+    crossScalaVersions := List(scala212, scala211),
+    scalacOptions ++= List(
+      "-Xexperimental",
+      "-deprecation"
+    ),
     organization := "org.scalameta",
     licenses := Seq(
       "Apache-2.0" -> url("http://www.apache.org/licenses/LICENSE-2.0")
@@ -28,6 +35,8 @@ inThisBuild(
 
 name := "mdocRoot"
 skip in publish := true
+crossScalaVersions := Nil
+
 val V = new {
   val scalameta = "4.1.0"
 }
@@ -105,9 +114,6 @@ lazy val unit = project
   .in(file("tests/unit"))
   .settings(
     skip in publish := true,
-    scalacOptions ++= List(
-      "-deprecation"
-    ),
     addCompilerPlugin("org.spire-math" %% "kind-projector" % "0.9.8"),
     resolvers += Resolver.bintrayRepo("cibotech", "public"),
     libraryDependencies ++= List(
@@ -134,6 +140,7 @@ lazy val plugin = project
   .settings(
     sbtPlugin := true,
     sbtVersion in pluginCrossBuild := "1.0.0",
+    crossScalaVersions := List(scala212),
     moduleName := "sbt-mdoc",
     libraryDependencies ++= List(
       "org.jsoup" % "jsoup" % "1.11.3",

tests/unit/src/test/scala/tests/cli/ScalacOptionsSuite.scala

@@ -1,31 +1,34 @@
 package tests.cli
 
+import tests.markdown.Compat
+
 class ScalacOptionsSuite extends BaseCliSuite {
-  checkCli(
-    "-Ywarn-unused-import",
-    """
-      |/index.md
-      |# Hello
-      |```scala mdoc
-      |import scala.concurrent.Future
-      |```
+  if (Compat.isScala212)
+    checkCli(
+      "-Ywarn-unused-import",
+      """
+        |/index.md
+        |# Hello
+        |```scala mdoc
+        |import scala.concurrent.Future
+        |```
     """.stripMargin,
-    "",
-    extraArgs = Array(
-      "--report-relative-paths",
-      "--scalac-options",
-      "-Ywarn-unused -Xfatal-warnings"
-    ),
-    expectedExitCode = 1,
-    onStdout = { out =>
-      val expected =
-        """
-          |warning: index.md:3:1: Unused import
-          |import scala.concurrent.Future
-          |^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^""".stripMargin
-      assert(out.contains(expected))
-    }
-  )
+      "",
+      extraArgs = Array(
+        "--report-relative-paths",
+        "--scalac-options",
+        "-Ywarn-unused -Xfatal-warnings"
+      ),
+      expectedExitCode = 1,
+      onStdout = { out =>
+        val expected =
+          """
+            |warning: index.md:3:1: Unused import
+            |import scala.concurrent.Future
+            |^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^""".stripMargin
+        assert(out.contains(expected))
+      }
+    )
 
   checkCli(
     "kind-projector",

tests/unit/src/test/scala/tests/markdown/AsyncSuite.scala

@@ -39,7 +39,25 @@ class AsyncSuite extends BaseMarkdownSuite {
        |	at repl.Session$App$.<init>(timeout.md:11)
        |	at repl.Session$App$.<clinit>(timeout.md)
        |	... 1 more
+    """.stripMargin,
+    compat = Map(
+      "2.11" ->
+        """|error: timeout.md:4:1: Futures timed out after [10 milliseconds]
+           |Await.result(Future(Thread.sleep(1000)), Duration("10ms"))
+           |^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+           |java.lang.ExceptionInInitializerError
+           |	at repl.Session$.app(timeout.md:3)
+           |Caused by: java.util.concurrent.TimeoutException: Futures timed out after [10 milliseconds]
+           |	at scala.concurrent.impl.Promise$DefaultPromise.ready(Promise.scala:223)
+           |	at scala.concurrent.impl.Promise$DefaultPromise.result(Promise.scala:227)
+           |	at scala.concurrent.Await$$anonfun$result$1.apply(package.scala:190)
+           |	at scala.concurrent.BlockContext$DefaultBlockContext$.blockOn(BlockContext.scala:53)
+           |	at scala.concurrent.Await$.result(package.scala:190)
+           |	at repl.Session$App$.<init>(timeout.md:11)
+           |	at repl.Session$App$.<clinit>(timeout.md)
+           |	... 1 more
     """.stripMargin
+    )
   )
 
   check(

tests/unit/src/test/scala/tests/markdown/BaseMarkdownSuite.scala

@@ -59,7 +59,8 @@ abstract class BaseMarkdownSuite extends org.scalatest.FunSuite with DiffAsserti
       name: String,
       original: String,
       expected: String,
-      settings: Settings = baseSettings
+      settings: Settings = baseSettings,
+      compat: Map[String, String] = Map.empty
   ): Unit = {
     test(name) {
       val reporter = newReporter()
@@ -68,7 +69,7 @@ abstract class BaseMarkdownSuite extends org.scalatest.FunSuite with DiffAsserti
       Markdown.toMarkdown(input, getMarkdownSettings(context), reporter, settings)
       assert(reporter.hasErrors, "Expected errors but reporter.hasErrors=false")
       val obtainedErrors = fansi.Str(myStdout.toString).plainText.trimLineEnds
-      assertNoDiffOrPrintExpected(obtainedErrors, expected)
+      assertNoDiffOrPrintExpected(obtainedErrors, Compat(expected, compat))
     }
   }
 
@@ -100,7 +101,7 @@ abstract class BaseMarkdownSuite extends org.scalatest.FunSuite with DiffAsserti
       settings: Settings = baseSettings
   ): Unit = {
     checkCompiles(name, original, settings, obtained => {
-      assertNoDiffOrPrintExpected(obtained, expected)
+      assertNoDiffOrPrintExpected(obtained, Compat(expected, Map.empty))
     })
   }
 

tests/unit/src/test/scala/tests/markdown/Compat.scala

@@ -0,0 +1,20 @@
+package tests.markdown
+
+import mdoc.internal.BuildInfo
+
+object Compat {
+  def isScala212: Boolean = BuildInfo.scalaVersion.startsWith("2.12")
+  def apply(default: String, compat: Map[String, String]): String = {
+    compat
+      .get(BuildInfo.scalaVersion)
+      .orElse(compat.get(BuildInfo.scalaBinaryVersion))
+      .getOrElse(
+        BuildInfo.scalaBinaryVersion match {
+          case "2.11" =>
+            default
+              .replaceAllLiterally("Predef.scala:288", "Predef.scala:230")
+          case _ => default
+        }
+      )
+  }
+}

tests/unit/src/test/scala/tests/markdown/MarkdownCompilerSuite.scala

@@ -19,11 +19,19 @@ class MarkdownCompilerSuite extends FunSuite with DiffAssertions {
   def check(name: String, original: String, expected: String): Unit =
     check(name, original :: Nil, expected)
 
-  def check(name: String, original: List[String], expected: String): Unit = {
+  def check(
+      name: String,
+      original: List[String],
+      expected: String,
+      compat: Map[String, String] = Map.empty
+  ): Unit = {
     test(name) {
       val inputs = original.map(s => Input.String(s))
       val obtained = Renderer.render(inputs, compiler, reporter, name + ".md", ReplVariablePrinter)
-      assertNoDiff(obtained, expected)
+      assertNoDiff(
+        obtained,
+        Compat(expected, compat)
+      )
     }
   }
 
@@ -46,7 +54,20 @@ class MarkdownCompilerSuite extends FunSuite with DiffAssertions {
       |val y = x.length
       |// y: Int = 10
       |```
-    """.stripMargin
+    """.stripMargin,
+    compat = Map(
+      "2.11" ->
+        """
+          |```scala
+          |val x = 1.to(10)
+          |// x: Range.Inclusive = Range(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+          |```
+          |```scala
+          |val y = x.length
+          |// y: Int = 10
+          |```
+        """.stripMargin
+    )
   )
 
   check(