fix(lsp): prevent stale diagnostics by syncing didChange

src/tools/lsp/client.ts

@@ -215,6 +215,8 @@ export class LSPClient {
   private proc: Subprocess<"pipe", "pipe", "pipe"> | null = null
   private connection: MessageConnection | null = null
   private openedFiles = new Set<string>()
+  private documentVersions = new Map<string, number>()
+  private lastSyncedText = new Map<string, string>()
   private stderrBuffer: string[] = []
   private processExited = false
   private diagnosticsStore = new Map<string, Diagnostic[]>()
@@ -432,23 +434,50 @@ export class LSPClient {
 
   async openFile(filePath: string): Promise<void> {
     const absPath = resolve(filePath)
-    if (this.openedFiles.has(absPath)) return
 
+    const uri = pathToFileURL(absPath).href
     const text = readFileSync(absPath, "utf-8")
-    const ext = extname(absPath)
-    const languageId = getLanguageId(ext)
 
-    this.sendNotification("textDocument/didOpen", {
-      textDocument: {
-        uri: pathToFileURL(absPath).href,
-        languageId,
-        version: 1,
-        text,
-      },
+    if (!this.openedFiles.has(absPath)) {
+      const ext = extname(absPath)
+      const languageId = getLanguageId(ext)
+      const version = 1
+
+      this.sendNotification("textDocument/didOpen", {
+        textDocument: {
+          uri,
+          languageId,
+          version,
+          text,
+        },
+      })
+
+      this.openedFiles.add(absPath)
+      this.documentVersions.set(uri, version)
+      this.lastSyncedText.set(uri, text)
+      await new Promise((r) => setTimeout(r, 1000))
+      return
+    }
+
+    const prevText = this.lastSyncedText.get(uri)
+    if (prevText === text) {
+      return
+    }
+
+    const nextVersion = (this.documentVersions.get(uri) ?? 1) + 1
+    this.documentVersions.set(uri, nextVersion)
+    this.lastSyncedText.set(uri, text)
+
+    this.sendNotification("textDocument/didChange", {
+      textDocument: { uri, version: nextVersion },
+      contentChanges: [{ text }],
     })
-    this.openedFiles.add(absPath)
 
-    await new Promise((r) => setTimeout(r, 1000))
+    // Some servers update diagnostics only after save
+    this.sendNotification("textDocument/didSave", {
+      textDocument: { uri },
+      text,
+    })
   }
 
   async definition(filePath: string, line: number, character: number): Promise<unknown> {