Allow multiple instances of the server on a single process.

src/LanguageServerProtocol.fs

@@ -16,17 +16,21 @@ module Server =
 
   let logger = LogProvider.getLoggerByName "LSP Server"
 
-  let jsonRpcFormatter = new JsonMessageFormatter()
-  jsonRpcFormatter.JsonSerializer.NullValueHandling <- NullValueHandling.Ignore
-  jsonRpcFormatter.JsonSerializer.ConstructorHandling <- ConstructorHandling.AllowNonPublicDefaultConstructor
-  jsonRpcFormatter.JsonSerializer.MissingMemberHandling <- MissingMemberHandling.Ignore
-  jsonRpcFormatter.JsonSerializer.Converters.Add(StrictNumberConverter())
-  jsonRpcFormatter.JsonSerializer.Converters.Add(StrictStringConverter())
-  jsonRpcFormatter.JsonSerializer.Converters.Add(StrictBoolConverter())
-  jsonRpcFormatter.JsonSerializer.Converters.Add(SingleCaseUnionConverter())
-  jsonRpcFormatter.JsonSerializer.Converters.Add(OptionConverter())
-  jsonRpcFormatter.JsonSerializer.Converters.Add(ErasedUnionConverter())
-  jsonRpcFormatter.JsonSerializer.ContractResolver <- OptionAndCamelCasePropertyNamesContractResolver()
+  let defaultJsonRpcFormatter() =
+    let jsonRpcFormatter = new JsonMessageFormatter()
+    jsonRpcFormatter.JsonSerializer.NullValueHandling <- NullValueHandling.Ignore
+    jsonRpcFormatter.JsonSerializer.ConstructorHandling <- ConstructorHandling.AllowNonPublicDefaultConstructor
+    jsonRpcFormatter.JsonSerializer.MissingMemberHandling <- MissingMemberHandling.Ignore
+    jsonRpcFormatter.JsonSerializer.Converters.Add(StrictNumberConverter())
+    jsonRpcFormatter.JsonSerializer.Converters.Add(StrictStringConverter())
+    jsonRpcFormatter.JsonSerializer.Converters.Add(StrictBoolConverter())
+    jsonRpcFormatter.JsonSerializer.Converters.Add(SingleCaseUnionConverter())
+    jsonRpcFormatter.JsonSerializer.Converters.Add(OptionConverter())
+    jsonRpcFormatter.JsonSerializer.Converters.Add(ErasedUnionConverter())
+    jsonRpcFormatter.JsonSerializer.ContractResolver <- OptionAndCamelCasePropertyNamesContractResolver()
+    jsonRpcFormatter
+
+  let jsonRpcFormatter = defaultJsonRpcFormatter()
 
   let deserialize<'t> (token: JToken) = token.ToObject<'t>(jsonRpcFormatter.JsonSerializer)
   let serialize<'t> (o: 't) = JToken.FromObject(o, jsonRpcFormatter.JsonSerializer)
@@ -95,7 +99,7 @@ module Server =
     (customizeRpc: IJsonRpcMessageHandler -> JsonRpc)
     =
 
-    use jsonRpcHandler = new HeaderDelimitedMessageHandler(output, input, jsonRpcFormatter)
+    use jsonRpcHandler = new HeaderDelimitedMessageHandler(output, input, defaultJsonRpcFormatter())
     // Without overriding isFatalException, JsonRpc serializes exceptions and sends them to the client.
     // This is particularly bad for notifications such as textDocument/didChange which don't require a response,
     // and thus any exception that happens during e.g. text sync gets swallowed.

tests/Ionide.LanguageServerProtocol.Tests.fsproj

@@ -1,4 +1,4 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
@@ -10,6 +10,7 @@
     <Compile Include="Utils.fs" />
     <Compile Include="Benchmarks.fs" />
     <Compile Include="Shotgun.fs" />
+    <Compile Include="StartWithSetup.fs" />
     <Compile Include="Tests.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>

tests/StartWithSetup.fs

@@ -0,0 +1,74 @@
+module Ionide.LanguageServerProtocol.Tests.StartWithSetup
+
+open Expecto
+open System.IO.Pipes
+open System.IO
+open Ionide.LanguageServerProtocol
+open Ionide.LanguageServerProtocol.Server
+
+type TestLspClient(sendServerNotification: ClientNotificationSender, sendServerRequest: ClientRequestSender) =
+    inherit LspClient ()
+
+let setupEndpoints(_: LspClient): Map<string, System.Delegate> =
+    [] |> Map.ofList
+
+let requestWithContentLength(request: string) =
+    @$"Content-Length: {request.Length}
+
+{request}"
+
+let shutdownRequest = @"{""jsonrpc"":""2.0"",""method"":""shutdown"",""id"":1}"
+
+let exitRequest = @"{""jsonrpc"":""2.0"",""method"":""exit"",""id"":1}"
+
+let tests =
+  testList
+    "startWithSetup"
+    [
+      testAsync "can start up multiple times in same process" {
+        use inputServerPipe1 = new AnonymousPipeServerStream()
+        use inputClientPipe1 = new AnonymousPipeClientStream(inputServerPipe1.GetClientHandleAsString())
+        use outputServerPipe1 = new AnonymousPipeServerStream()
+
+        use inputWriter1 = new StreamWriter(inputServerPipe1)
+        inputWriter1.AutoFlush <- true
+        let server1 = async {
+            let result = (startWithSetup
+                setupEndpoints
+                inputClientPipe1
+                outputServerPipe1
+                TestLspClient
+                defaultRpc)
+            Expect.equal (int result) 0 "server startup failed"
+        }
+
+        let! server1Async = Async.StartChild(server1)
+
+        use inputServerPipe2 = new AnonymousPipeServerStream()
+        use inputClientPipe2 = new AnonymousPipeClientStream(inputServerPipe2.GetClientHandleAsString())
+        use outputServerPipe2 = new AnonymousPipeServerStream()
+
+        use inputWriter2 = new StreamWriter(inputServerPipe2)
+        inputWriter2.AutoFlush <- true
+        let server2 = async {
+            let result = (startWithSetup
+                setupEndpoints
+                inputClientPipe2
+                outputServerPipe2
+                TestLspClient
+                defaultRpc)
+            Expect.equal (int result) 0 "server startup failed"
+        }
+
+        let! server2Async = Async.StartChild(server2)
+
+        inputWriter1.Write(requestWithContentLength(shutdownRequest))
+        inputWriter1.Write(requestWithContentLength(exitRequest))
+
+        inputWriter2.Write(requestWithContentLength(shutdownRequest))
+        inputWriter2.Write(requestWithContentLength(exitRequest))
+
+        do! server1Async
+        do! server2Async
+      }
+    ]

tests/Tests.fs

@@ -874,7 +874,8 @@ let private serializationTests =
                     Data = None }
                testThereAndBackAgain item
         ]
-      Shotgun.tests ]
+      Shotgun.tests
+      StartWithSetup.tests ]
 
 [<Tests>]
 let tests = testList "LSP" [ serializationTests; Utils.tests ]