From ca0f32f8fb0d813969ad56f4b5a3ff67e0f8ef91 Mon Sep 17 00:00:00 2001
From: Friedrich von Never <friedrich@fornever.me>
Date: Sun, 24 Mar 2024 22:46:24 +0100
Subject: [PATCH] (#248) LSP: more robust service calls, log more errors

---
 .../lang/lsp/ide/LSPRequestManager.kt         | 41 +++++++++----------
 .../languagehost/TextDocumentServiceQueue.kt  | 30 +++++++-------
 2 files changed, 34 insertions(+), 37 deletions(-)

diff --git a/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/ide/LSPRequestManager.kt b/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/ide/LSPRequestManager.kt
index fa5073f0..218555fb 100644
--- a/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/ide/LSPRequestManager.kt
+++ b/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/ide/LSPRequestManager.kt
@@ -3,6 +3,7 @@
  */
 package com.intellij.plugin.powershell.lang.lsp.ide
 
+import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.diagnostic.thisLogger
 import com.intellij.openapi.progress.ProcessCanceledException
 import com.intellij.plugin.powershell.lang.lsp.languagehost.LanguageServerEndpoint
@@ -22,42 +23,36 @@ class LSPRequestManager(
   private fun checkStatus(): Boolean = serverEndpoint.isRunning
 
   suspend fun didClose(params: DidCloseTextDocumentParams) {
-    if (checkStatus()) {
-      handleServerError {
-        if (documentSyncOptions == null || documentSyncOptions.openClose) queue.didClose(params)
-      }
+    serviceCall {
+      if (documentSyncOptions == null || documentSyncOptions.openClose) queue.didClose(params)
     }
   }
 
   suspend fun didOpen(params: DidOpenTextDocumentParams) {
-    if (checkStatus()) {
-      handleServerError {
-        if (documentSyncOptions == null || documentSyncOptions.openClose) queue.didOpen(params)
-      }
+    serviceCall {
+      if (documentSyncOptions == null || documentSyncOptions.openClose) queue.didOpen(params)
     }
   }
 
   suspend fun didChange(params: DidChangeTextDocumentParams) {
-    if (checkStatus()) {
-      handleServerError {
-        if (documentSyncOptions == null || documentSyncOptions.change != null) queue.didChange(params)
-      }
+    serviceCall {
+      if (documentSyncOptions == null || documentSyncOptions.change != null) queue.didChange(params)
     }
   }
 
-  suspend fun completion(params: CompletionParams): Either<List<CompletionItem>, CompletionList>? {
-    if (checkStatus()) {
-      return handleServerError {
-        if (capabilities.completionProvider != null)
-          queue.completion(params)
-        else null
-      }
+  suspend fun completion(params: CompletionParams): Either<List<CompletionItem>, CompletionList>? =
+    serviceCall {
+      if (capabilities.completionProvider != null)
+        queue.completion(params)
+      else null
     }
 
-    return null
-  }
+  private suspend fun <T> serviceCall(action: suspend () -> T): T? {
+    if (!checkStatus()) {
+      logger.error("ServerEndpoint does not report isRunning == true")
+      return null
+    }
 
-  private suspend fun <T> handleServerError(action: suspend () -> T): T? {
     try {
       return action()
     } catch (e: Throwable) {
@@ -71,3 +66,5 @@ class LSPRequestManager(
     }
   }
 }
+
+private val logger = logger<LSPRequestManager>()
diff --git a/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/languagehost/TextDocumentServiceQueue.kt b/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/languagehost/TextDocumentServiceQueue.kt
index 764098b3..d7f0d0d1 100644
--- a/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/languagehost/TextDocumentServiceQueue.kt
+++ b/src/main/kotlin/com/intellij/plugin/powershell/lang/lsp/languagehost/TextDocumentServiceQueue.kt
@@ -15,11 +15,8 @@ private val logger = logger<TextDocumentServiceQueue>()
 
 class TextDocumentServiceQueue(private val textDocumentService: () -> TextDocumentService?) {
 
-  private val service: TextDocumentService?
-    get() = textDocumentService()
-
   private val mutex = Mutex()
-  private suspend fun <T> executeTask(id: String, logDescription: Any? = null, task: suspend () -> T): T {
+  private suspend fun <T> executeTask(id: String, logDescription: Any? = null, task: suspend (TextDocumentService) -> T): T? {
     logger.trace {
       val summary = "$id: operation queued."
       val description = logDescription?.toString()
@@ -32,7 +29,10 @@ class TextDocumentServiceQueue(private val textDocumentService: () -> TextDocume
       withContext(Dispatchers.IO) {
         logger.trace { "$id: executing on the IO context." }
         try {
-          task()
+          textDocumentService()?.let { task(it) } ?: run {
+            logger.error("Cannot get the service to perform task $id.")
+            null
+          }
         } finally {
           logger.trace { "$id: finished." }
         }
@@ -41,31 +41,31 @@ class TextDocumentServiceQueue(private val textDocumentService: () -> TextDocume
   }
 
   suspend fun didOpen(params: DidOpenTextDocumentParams) {
-    executeTask("didOpen notification", params) {
-      service?.didOpen(params)
+    executeTask("didOpen notification", params) { service ->
+      service.didOpen(params)
     }
   }
 
   suspend fun didClose(params: DidCloseTextDocumentParams) {
-    executeTask("didClose notification", params) {
-      service?.didClose(params)
+    executeTask("didClose notification", params) { service ->
+      service.didClose(params)
     }
   }
 
   suspend fun didSave(params: DidSaveTextDocumentParams) {
-    executeTask("didSave notification", params) {
-      service?.didSave(params)
+    executeTask("didSave notification", params) { service ->
+      service.didSave(params)
     }
   }
 
   suspend fun didChange(params: DidChangeTextDocumentParams) {
-    executeTask("didChange notification", params) {
-      service?.didChange(params)
+    executeTask("didChange notification", params) { service ->
+      service.didChange(params)
     }
   }
 
   suspend fun completion(params: CompletionParams): Either<List<CompletionItem>, CompletionList>? =
-    executeTask("completion request", params) {
-      service?.completion(params)?.await()
+    executeTask("completion request", params) { service ->
+      service.completion(params)?.await()
     }
 }