fix(debugger): type input for the program in the debug console (#1614)

A program started through runInTerminal had stdin from /dev/null, and CodeLLDB's launcher only hands the program a terminal it can read from when it runs on one. runInTerminal now starts the command on a pseudo-terminal, forwards its output to the console (CRLF as LF, without CodeLLDB's clear-screen request) and reports that the program takes input; while it runs, the console's input line goes to it, while paused it evaluates as before. debugpy and js-debug programs started in a terminal get the same.

src/features/debugger/state.ts

@@ -45,6 +45,8 @@ export interface DebugSession {
   parent: DebugSessionId | null;
   /** Launch configuration (root sessions), used by Rerun. */
   launch: LaunchConfig | null;
+  /** The program runs in a terminal the IDE gave it: the console types into it while it runs. */
+  programInput?: boolean;
   /** Process the session is attached to (a Run tab's build tool); stopped with the session. */
   process: RunId | null;
   status: SessionStatus;
@@ -944,6 +946,16 @@ export async function setVariableValue(
   return result;
 }
 
+/** Whether the console types into the session's program (it runs, in a terminal the IDE gave it). */
+export function readsProgramInput(s: DebugSession): boolean {
+  return !!s.programInput && s.status === "running";
+}
+
+/** Types `text` into the session's program; its terminal echoes it to the console. */
+export async function sendProgramInput(session: DebugSession, text: string): Promise<void> {
+  await call(commands.debugSendInput(session.id, text));
+}
+
 export async function evaluate(
   expression: string,
   context: "repl" | "watch" | "hover" | "clipboard",
@@ -1022,6 +1034,9 @@ export function handleDebugEvent(id: DebugSessionId, event: DebugEvent) {
     case "thread":
       if (s.status === "paused") void loadThreads(id);
       break;
+    case "programInput":
+      patch(id, { programInput: true });
+      break;
     case "breakpointsChanged":
       void refreshStates(event.path);
       break;

src/features/debugger/ui/DebugConsole.tsx

@@ -16,7 +16,16 @@ import {
   type FindOptions,
   type FindResult,
 } from "@/ui/consoleFind";
-import { appendConsole, clearConsole, evaluate, isLive, useDebug, type DebugSession } from "../state";
+import {
+  appendConsole,
+  clearConsole,
+  evaluate,
+  isLive,
+  readsProgramInput,
+  sendProgramInput,
+  useDebug,
+  type DebugSession,
+} from "../state";
 import { pushHistory, readHistory, setConsoleHistoryBrowser } from "./expressionHistory";
 import { useExpressionCompletion } from "./ExpressionCompletion";
 import styles from "./DebugToolWindow.module.css";
@@ -245,6 +254,16 @@ export function DebugConsole({ session, interactive = true }: { session: DebugSe
   }, [findOpen, current, virtualizer]);
 
   const submit = async () => {
+    if (readsProgramInput(session)) {
+      // Like the Run console: the line as typed, empty or not, goes to the program.
+      setInput("");
+      try {
+        await sendProgramInput(session, `${input}\n`);
+      } catch (err) {
+        appendConsole(session.id, "stderr", `${err instanceof Error ? err.message : String(err)}\n`);
+      }
+      return;
+    }
     const e = input.trim();
     if (!e) return;
     pushHistory("console", e);
@@ -466,10 +485,16 @@ export function DebugConsole({ session, interactive = true }: { session: DebugSe
                 value={input}
                 onChange={(e) => {
                   setInput(e.target.value);
-                  completion.onInput();
+                  if (!readsProgramInput(session)) completion.onInput();
                 }}
                 onKeyDown={onKeyDown}
-                placeholder={isLive(session) ? "Evaluate in the debug console" : "Session finished"}
+                placeholder={
+                  !isLive(session)
+                    ? "Session finished"
+                    : readsProgramInput(session)
+                      ? "Input for the program (pause to evaluate)"
+                      : "Evaluate in the debug console"
+                }
                 disabled={!isLive(session)}
                 aria-label={tx("Debug console input")}
                 spellCheck={false}