Show error notification in client for expectable test discovery issues (i.e projects not restored or built)

Author: farlee2121

src/FsAutoComplete/LspServers/AdaptiveServerState.fs

@@ -2599,6 +2599,28 @@ type AdaptiveState
       let! testProjects = TestProjectHelpers.tryGetTestProjects workspaceLoader state.WorkspacePaths
       let testProjectBinaries = testProjects |> List.map _.TargetPath
 
+      if testProjects |> List.isEmpty then
+        let message = "No test projects found. Make sure you've restored your projects"
+
+        do!
+          lspClient.WindowShowMessage(
+            { Type = MessageType.Error
+              Message = message }
+          )
+
+        return! (Error message)
+      elif testProjectBinaries |> List.filter File.Exists |> List.isEmpty then
+        let message =
+          "No binaries found for test projects. Make sure you've built your projects"
+
+        do!
+          lspClient.WindowShowMessage(
+            { Type = MessageType.Error
+              Message = message }
+          )
+
+        return! (Error message)
+
       let tryTestCasesToDTOs testCases =
         let projectLookup = testProjects |> Seq.map (fun p -> p.TargetPath, p) |> Map.ofSeq
 

test/FsAutoComplete.Tests.Lsp/TestExplorerTests.fs

@@ -64,7 +64,19 @@ let tests createServer =
   testSequenced
   <| testList
     "TestExplorerTests"
-    [ testCaseAsync "it should report tests of all basic outcomes"
+    [ testCaseAsync "it should error if the workspace hasn't been built"
+      <| async {
+        let workspaceRoot =
+          Path.Combine(__SOURCE_DIRECTORY__, "SampleTestProjects", "VSTest.XUnit.RunResults")
+
+        let! server, _ = initializeServer workspaceRoot
+        use server = server
+
+        let! res = server.TestDiscoverTests()
+
+        Expect.isTrue res.IsError ""
+      }
+      testCaseAsync "it should report tests of all basic outcomes"
       <| async {
         let workspaceRoot =
           Path.Combine(__SOURCE_DIRECTORY__, "SampleTestProjects", "VSTest.XUnit.RunResults")