Add tests for autocompletions

Add basic autocompletion tests for project autocompletion. The current
tests are basic and will be expanded in the future (contributions are
welcome).

Fixes #426

backend/src/test/scala/bloop/logging/RecordingLogger.scala

@@ -15,6 +15,7 @@ final class RecordingLogger(
 
   def clear(): Unit = messages.clear()
 
+  def infos: List[String] = getMessagesAt(Some("info"))
   def getMessagesAt(level: Option[String]): List[String] = getMessages(level).map(_._2)
   def getMessages(): List[(String, String)] = getMessages(None)
   private def getMessages(level: Option[String]): List[(String, String)] = {

frontend/src/main/scala/bloop/cli/Commands.scala

@@ -3,10 +3,8 @@ package bloop.cli
 import java.net.InetAddress
 import java.nio.file.Path
 
-import bloop.cli.CliParsers.CommandsMessages
 import bloop.io.AbsolutePath
 import caseapp.{CommandName, ExtraName, HelpMessage, Recurse}
-import caseapp.core.CommandMessages
 
 object Commands {
 

frontend/src/test/scala/bloop/AutoCompleteSpec.scala

@@ -0,0 +1,78 @@
+package bloop
+
+import bloop.cli.{CliOptions, Commands, completion}
+import bloop.engine.Run
+import bloop.logging.RecordingLogger
+import bloop.util.TestUtil
+import org.junit.Test
+
+class AutoCompleteSpec {
+  @Test
+  def testAutoCompletionForProjects: Unit = {
+    val structure = Map("A" -> Map[String, String](), "B" -> Map[String, String]())
+    val deps = Map("B" -> Set("A"))
+    val logger = new RecordingLogger(ansiCodesSupported = false)
+
+    TestUtil.testState(structure, deps, userLogger = Some(logger)) { state0 =>
+      val cliOptions = CliOptions.default.copy(common = state0.commonOptions)
+      val test1 = Commands.Autocomplete(
+        cliOptions,
+        completion.Mode.Commands,
+        completion.ZshFormat,
+        None,
+        None
+      )
+
+      val test2 = Commands.Autocomplete(
+        cliOptions,
+        completion.Mode.ProjectBoundCommands,
+        completion.ZshFormat,
+        None,
+        None
+      )
+
+      // Simulate basic 'bloop compile <autocomplete>'
+      val test3 = Commands.Autocomplete(
+        cliOptions,
+        completion.Mode.Projects,
+        completion.ZshFormat,
+        Some("compile"),
+        None
+      )
+
+      // Simulate 'bloop compile A <autocomplete>', happens when we want to add multiple projects
+      val test4 = Commands.Autocomplete(
+        cliOptions,
+        completion.Mode.Projects,
+        completion.ZshFormat,
+        Some("compile"),
+        Some("A")
+      )
+
+      val action = Run(test1, Run(test2, Run(test3, Run(test4))))
+      val state1 = TestUtil.blockingExecute(action, state0)
+      TestUtil.assertNoDiff(
+        """
+          |about
+          |autocomplete
+          |bsp
+          |clean
+          |compile
+          |configure
+          |console
+          |help
+          |link
+          |projects
+          |run
+          |test
+          |clean compile console link run test
+          |A
+          |B
+          |A
+          |B
+        """.stripMargin,
+        logger.infos.mkString(System.lineSeparator)
+      )
+    }
+  }
+}