From db5f33e961ed78eaa43ea75dbb8bfefc16ebff48 Mon Sep 17 00:00:00 2001
From: Quinten Kock <quintenkock@gmail.com>
Date: Tue, 2 Dec 2025 23:22:39 +0100
Subject: [PATCH] Fix diagnostic propagation

---
 src/app/filestate.ts       | 23 +++++++++++-----
 src/app/lsp.ts             | 16 ++++++++---
 src/app/lsp/diagnostics.ts | 55 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 10 deletions(-)
 create mode 100644 src/app/lsp/diagnostics.ts

diff --git a/src/app/filestate.ts b/src/app/filestate.ts
index 343b17e..8c2f512 100644
--- a/src/app/filestate.ts
+++ b/src/app/filestate.ts
@@ -8,6 +8,7 @@ import {
     ChangeSet,
 } from "@codemirror/state";
 import { history } from "@codemirror/commands";
+import { Diagnostic, setDiagnostics } from "@codemirror/lint";
 import { Editor } from "./editor";
 import van, { State } from "vanjs-core";
 import { WorkspaceFile } from "@codemirror/lsp-client";
@@ -104,6 +105,11 @@ export class OpenFile implements WorkspaceFile {
     createEditor(): Editor {
         const editor = new Editor(this);
         this.editors.push(editor);
+        editor.dispatch(
+            editor.view.state.update(
+                setDiagnostics(editor.view.state, this.diagnostics || []),
+            ),
+        );
         return editor;
     }
 
@@ -172,12 +178,7 @@ export class OpenFile implements WorkspaceFile {
             es.forEach((e) => e.dispatch(e.view.state.update(trs), true));
         } else {
             this.editors.forEach((e) => {
-                const changes = transaction.changes;
-                const userEvent = transaction.annotation(Transaction.userEvent);
-                const annotations = userEvent
-                    ? [Transaction.userEvent.of(userEvent)]
-                    : [];
-                e.dispatch(e.view.state.update({ changes, annotations }), true);
+                e.dispatch(e.view.state.update(trs), true);
             });
         }
     }
@@ -215,4 +216,14 @@ export class OpenFile implements WorkspaceFile {
         if (this.editors.length > 0) return this.editors[0].view;
         return null;
     }
+
+    private diagnostics: Diagnostic[];
+    setDiagnostics(diagnostics: Diagnostic[]) {
+        this.diagnostics = diagnostics;
+        for (const editor of this.editors) {
+            editor.view.dispatch(
+                setDiagnostics(editor.view.state, diagnostics),
+            );
+        }
+    }
 }
diff --git a/src/app/lsp.ts b/src/app/lsp.ts
index a80a978..143a539 100644
--- a/src/app/lsp.ts
+++ b/src/app/lsp.ts
@@ -7,11 +7,14 @@ import { EditorView } from "@codemirror/view";
 import {
     LSPClient,
     LSPPlugin,
-    languageServerExtensions,
     Workspace,
+    serverCompletion,
+    hoverTooltips,
+    signatureHelp,
 } from "@codemirror/lsp-client";
 
 import { OpenFile } from "./filestate";
+import { serverDiagnostics } from "./lsp/diagnostics";
 
 // Create a very small MessagePort-based transport implementation
 // compatible with @codemirror/lsp-client's expected Transport interface.
@@ -108,9 +111,9 @@ class OpenFileWorkspace extends Workspace {
                 file.version = this.nextFileVersion(file.uri);
                 file.changes = ChangeSet.empty(file.doc.length);
             }
-            for(const e of file.editors) {
+            for (const e of file.editors) {
                 const plugin = LSPPlugin.get(e.view);
-                if(plugin) {
+                if (plugin) {
                     plugin.clear();
                 }
             }
@@ -257,7 +260,12 @@ export async function createLspExtension(
 
     try {
         const client = new LSPClient({
-            extensions: languageServerExtensions(),
+            extensions: [
+                serverDiagnostics(),
+                serverCompletion(),
+                hoverTooltips(),
+                signatureHelp(),
+            ],
             rootUri: rootUri,
             workspace: (c) => new OpenFileWorkspace(c),
         });
diff --git a/src/app/lsp/diagnostics.ts b/src/app/lsp/diagnostics.ts
new file mode 100644
index 0000000..c52f4fa
--- /dev/null
+++ b/src/app/lsp/diagnostics.ts
@@ -0,0 +1,55 @@
+import type * as lsp from "vscode-languageserver-protocol"
+import {setDiagnostics} from "@codemirror/lint"
+import {ViewPlugin, ViewUpdate} from "@codemirror/view"
+import {LSPPlugin, LSPClientExtension} from "@codemirror/lsp-client"
+import {OpenFile} from "../filestate"
+import { Text } from "@codemirror/state"
+
+function toSeverity(sev: lsp.DiagnosticSeverity) {
+  return sev == 1 ? "error" : sev == 2 ? "warning" : sev == 3 ? "info" : "hint"
+}
+
+const autoSync = ViewPlugin.fromClass(class {
+  pending: any | null = null
+  update(update: ViewUpdate) {
+    if (update.docChanged) {
+      if (this.pending != null) clearTimeout(this.pending)
+      this.pending = setTimeout(() => {
+        this.pending = null
+        let plugin = LSPPlugin.get(update.view)
+        if (plugin) plugin.client.sync()
+      }, 500)
+    }
+  }
+  destroy() {
+    if (this.pending != null) clearTimeout(this.pending)
+  }
+})
+
+function fromPosition(doc: Text, pos: lsp.Position): number {
+  let line = doc.line(pos.line + 1)
+  return line.from + pos.character
+}
+
+export function serverDiagnostics(): LSPClientExtension {
+  return {
+    clientCapabilities: {textDocument: {publishDiagnostics: {versionSupport: true}}},
+    notificationHandlers: {
+      "textDocument/publishDiagnostics": (client, params: lsp.PublishDiagnosticsParams) => {
+        let file = client.workspace.getFile(params.uri) as OpenFile;
+        if (!file || params.version != null && params.version != file.version) return false;
+        for(const view of file.editors.map(e => e.view)) {
+          const mapPos = (p: number) => file.changes ? file.changes.mapPos(p) : p;
+          file.setDiagnostics(params.diagnostics.map(item => ({
+            from: mapPos(fromPosition(file.doc, item.range.start)),
+            to: mapPos(fromPosition(file.doc, item.range.end)),
+            severity: toSeverity(item.severity ?? 1),
+            message: item.message,
+          })));
+        }
+        return true
+      }
+    },
+    editorExtension: autoSync
+  }
+}