From fac2a9acb592bb195be14338f26292c15249a749 Mon Sep 17 00:00:00 2001
From: Radon Rosborough <radon.neon@gmail.com>
Date: Mon, 6 Jul 2020 14:15:24 -0600
Subject: [PATCH] Additional LSP diagnostics on frontend

---
 backend/src/api.ts  | 47 +++++++++++++++++++--------------------------
 frontend/src/app.ts | 24 ++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 28 deletions(-)

diff --git a/backend/src/api.ts b/backend/src/api.ts
index 951aec1..130af6e 100644
--- a/backend/src/api.ts
+++ b/backend/src/api.ts
@@ -55,21 +55,22 @@ export class Session {
     this.run().catch((err) => {
       this.log(`Error while setting up environment for pty`);
       console.log(err);
-      try {
-        this.ws.send(JSON.stringify({ event: "terminalClear" }));
-        this.ws.send(
-          JSON.stringify({
-            event: "terminalOutput",
-            output: `Riju encountered an unexpected error: ${err}
+      this.send({ event: "terminalClear" });
+      this.send({
+        event: "terminalOutput",
+        output: `Riju encountered an unexpected error: ${err}
 \rYou may want to save your code and refresh the page.
 `,
-          })
-        );
-      } catch (err) {
-        //
-      }
+      });
     });
   }
+  send = (msg: any) => {
+    try {
+      this.ws.send(JSON.stringify(msg));
+    } catch (err) {
+      //
+    }
+  };
   handleClientMessage = (event: string) => {
     let msg: any;
     try {
@@ -131,11 +132,7 @@ export class Session {
       this.term.pty.kill();
       this.term.live = false;
     }
-    try {
-      this.ws.send(JSON.stringify({ event: "terminalClear" }));
-    } catch (err) {
-      //
-    }
+    this.send({ event: "terminalClear" });
     if (this.homedir == null) {
       this.homedir = `/tmp/riju/${this.uuid}`;
       await callPrivileged(["setup", `${this.uid}`, this.uuid], this.log);
@@ -221,13 +218,7 @@ export class Session {
       // Capture term in closure so that we don't keep sending output
       // from the old pty even after it's been killed (see ghci).
       if (term.live) {
-        try {
-          this.ws.send(
-            JSON.stringify({ event: "terminalOutput", output: data })
-          );
-        } catch (err) {
-          //
-        }
+        this.send({ event: "terminalOutput", output: data });
       }
     });
     if (lsp && this.lsp === null) {
@@ -251,17 +242,19 @@ export class Session {
       const proc = spawn(lspArgs[0], lspArgs.slice(1), {
         env: getEnv(this.uuid),
       });
+      proc.on("exit", (code) => this.send({ event: "lspCrashed", code }));
+      proc.stderr.on("data", (data) =>
+        this.send({ event: "lspLog", output: data.toString("utf8") })
+      );
       this.lsp = {
         proc,
         reader: new rpc.StreamMessageReader(proc.stdout),
         writer: new rpc.StreamMessageWriter(proc.stdin),
       };
       this.lsp.reader.listen((data) => {
-        this.ws.send(JSON.stringify({ event: "lspOutput", output: data }));
+        this.send({ event: "lspOutput", output: data });
       });
-      this.ws.send(
-        JSON.stringify({ event: "lspStarted", root: `/tmp/riju/${this.uuid}` })
-      );
+      this.send({ event: "lspStarted", root: `/tmp/riju/${this.uuid}` });
     }
   };
   cleanup = async () => {
diff --git a/frontend/src/app.ts b/frontend/src/app.ts
index 045affa..c12ab85 100644
--- a/frontend/src/app.ts
+++ b/frontend/src/app.ts
@@ -119,6 +119,7 @@ async function main() {
   function tryConnect() {
     let clientDisposable: Disposable | null = null;
     let servicesDisposable: Disposable | null = null;
+    let lspLogBuffer = "";
     console.log("Connecting to server...");
     socket = new WebSocket(
       (document.location.protocol === "http:" ? "ws://" : "wss://") +
@@ -136,7 +137,11 @@ async function main() {
         console.error("Malformed message from server:", event.data);
         return;
       }
-      if (DEBUG && message?.event !== "lspOutput") {
+      if (
+        DEBUG &&
+        message?.event !== "lspOutput" &&
+        message?.event !== "lspLog"
+      ) {
         console.log("RECEIVE:", message);
       }
       if (message?.event && message?.event !== "error") {
@@ -198,6 +203,23 @@ async function main() {
         case "lspOutput":
           // Should be handled by RijuMessageReader
           return;
+        case "lspLog":
+          if (typeof message.output !== "string") {
+            console.error("Unexpected message from server:", message);
+            return;
+          }
+          if (DEBUG) {
+            lspLogBuffer += message.output;
+            while (lspLogBuffer.includes("\n")) {
+              const idx = lspLogBuffer.indexOf("\n");
+              const line = lspLogBuffer.slice(0, idx);
+              lspLogBuffer = lspLogBuffer.slice(idx + 1);
+              console.log(`LSP || ${line}`);
+            }
+          }
+          return;
+        case "lspCrashed":
+          return;
         default:
           console.error("Unexpected message from server:", message);
           return;