fix(coding-agent): avoid duplicate session reads

fixes #6793
2026-07-19 20:18:49 +02:00
parent 3da591ab74
commit f1c587dde3
3 changed files with 156 additions and 18 deletions
@@ -5,6 +5,8 @@ import { join } from "path";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { findMostRecentSession, loadEntriesFromFile, SessionManager } from "../../src/core/session-manager.ts";

+const HEADER_SCAN_LIMIT_BYTES = 1024 * 1024;
+
 describe("loadEntriesFromFile", () => {
 	let tempDir: string;

@@ -17,6 +19,19 @@ describe("loadEntriesFromFile", () => {
 		rmSync(tempDir, { recursive: true, force: true });
 	});

+	function writeSessionHeader(file: string, cwd: string, id: string, prefix = ""): void {
+		writeFileSync(
+			file,
+			`${prefix}${JSON.stringify({
+				type: "session",
+				version: 3,
+				id,
+				timestamp: "2025-01-01T00:00:00Z",
+				cwd,
+			})}\n`,
+		);
+	}
+
 	it("returns empty array for non-existent file", () => {
 		const entries = loadEntriesFromFile(join(tempDir, "nonexistent.jsonl"));
 		expect(entries).toEqual([]);
@@ -65,6 +80,43 @@ describe("loadEntriesFromFile", () => {
 		expect(entries).toHaveLength(2);
 	});

+	it.each([
+		["leading blank lines", "\n  \n", "leading-blank"],
+		["leading malformed lines", "not json\n{broken json\n", "leading-malformed"],
+		["a multi-buffer header", "", "a".repeat(8192)],
+	])("reads cwd from a session with %s", (_description, prefix, sessionId) => {
+		const file = join(tempDir, "header.jsonl");
+		const storedCwd = join(tempDir, "stored-project");
+		writeSessionHeader(file, storedCwd, sessionId, prefix);
+
+		const sessionManager = SessionManager.open(file, tempDir);
+		expect(sessionManager.getSessionId()).toBe(sessionId);
+		expect(sessionManager.getCwd()).toBe(storedCwd);
+	});
+
+	it("opens compatible sessions beyond the discovery scan limit", () => {
+		const storedCwd = join(tempDir, "stored-project");
+		const overrideCwd = join(tempDir, "override-project");
+		const cases = [
+			{ name: "large-header", id: "a".repeat(HEADER_SCAN_LIMIT_BYTES + 1), prefix: "" },
+			{
+				name: "large-prefix",
+				id: "large-prefix",
+				prefix: `${"x".repeat(HEADER_SCAN_LIMIT_BYTES + 1)}\n`,
+			},
+		];
+
+		for (const { name, id, prefix } of cases) {
+			const file = join(tempDir, `${name}.jsonl`);
+			writeSessionHeader(file, storedCwd, id, prefix);
+			for (const cwdOverride of [undefined, overrideCwd]) {
+				const sessionManager = SessionManager.open(file, tempDir, cwdOverride);
+				expect(sessionManager.getSessionId()).toBe(id);
+				expect(sessionManager.getCwd()).toBe(cwdOverride ?? storedCwd);
+			}
+		}
+	});
+
 	it("opens session files larger than Node's max string length", () => {
 		const file = join(tempDir, "large.jsonl");
 		writeFileSync(
@@ -155,6 +207,15 @@ describe("findMostRecentSession", () => {
 		expect(findMostRecentSession(tempDir)).toBe(valid);
 	});

+	it("skips oversized corrupt files and returns a valid session", () => {
+		const invalid = join(tempDir, "oversized.jsonl");
+		const valid = join(tempDir, "valid.jsonl");
+		writeFileSync(invalid, "x".repeat(HEADER_SCAN_LIMIT_BYTES + 1));
+		writeFileSync(valid, '{"type":"session","id":"abc","timestamp":"2025-01-01T00:00:00Z","cwd":"/tmp"}\n');
+
+		expect(findMostRecentSession(tempDir)).toBe(valid);
+	});
+
 	it("filters most recent session by cwd", async () => {
 		const projectA = join(tempDir, "project-a");
 		const projectB = join(tempDir, "project-b");