fix(coding-agent): use strict JSONL framing fixes #1911

packages/coding-agent/test/rpc-jsonl.test.ts

@@ -0,0 +1,65 @@
+import { Readable } from "node:stream";
+import { describe, expect, test } from "vitest";
+import { attachJsonlLineReader, serializeJsonLine } from "../src/modes/rpc/jsonl.js";
+
+describe("RPC JSONL framing", () => {
+	test("serializes strict JSONL records without escaping Unicode separators", () => {
+		const line = serializeJsonLine({ text: "a\u2028b\u2029c" });
+
+		expect(line).toContain("a\u2028b\u2029c");
+		expect(line.endsWith("\n")).toBe(true);
+		expect(JSON.parse(line.trim())).toEqual({ text: "a\u2028b\u2029c" });
+	});
+
+	test("splits on LF only and preserves U+2028/U+2029 inside payloads", async () => {
+		const lines: string[] = [];
+		const stream = Readable.from([serializeJsonLine({ text: "a\u2028b\u2029c" })]);
+
+		const done = new Promise<void>((resolve) => {
+			stream.on("end", resolve);
+		});
+
+		attachJsonlLineReader(stream, (line) => {
+			lines.push(line);
+		});
+
+		await done;
+
+		expect(lines).toHaveLength(1);
+		expect(JSON.parse(lines[0])).toEqual({ text: "a\u2028b\u2029c" });
+	});
+
+	test("handles CRLF-delimited input", async () => {
+		const lines: string[] = [];
+		const stream = Readable.from([Buffer.from('{"a":1}\r\n{"b":2}\r\n')]);
+
+		const done = new Promise<void>((resolve) => {
+			stream.on("end", resolve);
+		});
+
+		attachJsonlLineReader(stream, (line) => {
+			lines.push(line);
+		});
+
+		await done;
+
+		expect(lines).toEqual(['{"a":1}', '{"b":2}']);
+	});
+
+	test("emits a final line without trailing LF", async () => {
+		const lines: string[] = [];
+		const stream = Readable.from([Buffer.from('{"a":1}')]);
+
+		const done = new Promise<void>((resolve) => {
+			stream.on("end", resolve);
+		});
+
+		attachJsonlLineReader(stream, (line) => {
+			lines.push(line);
+		});
+
+		await done;
+
+		expect(lines).toEqual(['{"a":1}']);
+	});
+});