1 files changed, 87 insertions, 0 deletions
diff --git a/packages/bun-debug-adapter-protocol/src/debugger/signal.ts b/packages/bun-debug-adapter-protocol/src/debugger/signal.ts
new file mode 100644
index 000000000..2a1b05938
--- /dev/null
+++ b/packages/bun-debug-adapter-protocol/src/debugger/signal.ts
@@ -0,0 +1,87 @@
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import type { Server } from "node:net";
+import { createServer } from "node:net";
+import { EventEmitter } from "node:events";
+
+const isDebug = process.env.NODE_ENV === "development";
+
+export type UnixSignalEventMap = {
+  "Signal.listening": [string];
+  "Signal.error": [Error];
+  "Signal.received": [string];
+  "Signal.closed": [];
+};
+
+/**
+ * Starts a server that listens for signals on a UNIX domain socket.
+ */
+export class UnixSignal extends EventEmitter<UnixSignalEventMap> {
+  #path: string;
+  #server: Server;
+  #ready: Promise<void>;
+
+  constructor(path?: string) {
+    super();
+    this.#path = path ? parseUnixPath(path) : randomUnixPath();
+    this.#server = createServer();
+    this.#server.on("listening", () => this.emit("Signal.listening", this.#path));
+    this.#server.on("error", error => this.emit("Signal.error", error));
+    this.#server.on("close", () => this.emit("Signal.closed"));
+    this.#server.on("connection", socket => {
+      socket.on("data", data => {
+        this.emit("Signal.received", data.toString());
+      });
+    });
+    this.#ready = new Promise((resolve, reject) => {
+      this.#server.on("listening", resolve);
+      this.#server.on("error", reject);
+    });
+    this.#server.listen(this.#path);
+  }
+
+  emit<E extends keyof UnixSignalEventMap>(event: E, ...args: UnixSignalEventMap[E]): boolean {
+    if (isDebug) {
+      console.log(event, ...args);
+    }
+
+    return super.emit(event, ...args);
+  }
+
+  /**
+   * The path to the UNIX domain socket.
+   */
+  get url(): string {
+    return `unix://${this.#path}`;
+  }
+
+  /**
+   * Resolves when the server is listening or rejects if an error occurs.
+   */
+  get ready(): Promise<void> {
+    return this.#ready;
+  }
+
+  /**
+   * Closes the server.
+   */
+  close(): void {
+    this.#server.close();
+  }
+}
+
+function randomUnixPath(): string {
+  return join(tmpdir(), `${Math.random().toString(36).slice(2)}.sock`);
+}
+
+function parseUnixPath(path: string): string {
+  if (path.startsWith("/")) {
+    return path;
+  }
+  try {
+    const { pathname } = new URL(path);
+    return pathname;
+  } catch {
+    throw new Error(`Invalid UNIX path: ${path}`);
+  }
+}