test(e2e): route every context.db open through openTestDb with busy_timeout

The e2e suite runs many files in parallel against a shared context.db while the
plugin under test writes to it. Handles opened with the default busy_timeout=0
fail immediately with SQLITE_BUSY the instant another connection holds the write
lock, surfacing as flaky 'database is locked' failures (memory-injection,
cache-stability cascade) rather than real regressions.

Most write-handle opens set the pragma inline, but that left the footgun live:
memory-injection and all the pi-* direct opens had no timeout, and one
pi-todo-synthesis open was missing it too. Add one openTestDb() helper that
always sets busy_timeout and route every direct open (reader and writer) through
it, deleting the now-redundant inline pragmas. A bare new Database in a test can
no longer reintroduce the flake.

Author: ualtinok

packages/e2e-tests/src/test-db.ts

@@ -0,0 +1,24 @@
+import { Database } from "bun:sqlite";
+
+/**
+ * Open a SQLite handle for an e2e test with a non-zero `busy_timeout` always set.
+ *
+ * The e2e suite runs many files in parallel against a per-test shared
+ * `context.db` while the plugin under test writes to the same file. A handle
+ * opened with the default `busy_timeout = 0` fails immediately with SQLITE_BUSY
+ * the instant any other connection holds the write lock, which surfaces as
+ * flaky "database is locked" failures under load rather than a real regression.
+ * Setting a timeout makes the handle WAIT for the lock instead of failing.
+ *
+ * Every test that opens the context DB directly (reader or writer) must go
+ * through this helper so the timeout can never be forgotten — a bare
+ * `new Database(...)` in a test reintroduces the flake.
+ */
+export function openTestDb(
+	path: string,
+	options?: { readonly?: boolean; readwrite?: boolean },
+): Database {
+	const db = new Database(path, options);
+	db.exec("PRAGMA busy_timeout=5000");
+	return db;
+}

packages/e2e-tests/tests/cache-invariants.test.ts

@@ -41,6 +41,7 @@ import {
     mainAgentRequests,
 } from "../src/cache-analysis";
 import { TestHarness } from "../src/harness";
+import { openTestDb } from "../src/test-db";
 import type { MockUsage } from "../src/mock-provider/server";
 
 const HISTORIAN_SYSTEM_MARKER = "the hippocampus of a long-running coding agent";
@@ -185,9 +186,8 @@ function projectIdentity(): string {
 
 function writeContextDb<T>(fn: (db: Database) => T): T {
     const dbPath = join(h.opencode.env.dataDir, "cortexkit", "magic-context", "context.db");
-    const db = new Database(dbPath);
+    const db = openTestDb(dbPath);
     try {
-        db.query("PRAGMA busy_timeout = 5000").run();
         return fn(db);
     } finally {
         db.close();

packages/e2e-tests/tests/long-running-session.test.ts

@@ -9,6 +9,7 @@ import { resolveProjectIdentity } from "../../plugin/src/features/magic-context/
 import { computeSyntheticCallId } from "../../plugin/src/hooks/magic-context/todo-view";
 import { TestHarness } from "../src/harness";
 import type { MockUsage } from "../src/mock-provider/server";
+import { openTestDb } from "../src/test-db";
 
 const HISTORIAN_SYSTEM_MARKER = "the hippocampus of a long-running coding agent";
 
@@ -197,9 +198,8 @@ function contextDbPath(): string {
 }
 
 function writeDb(fn: (db: Database) => void): void {
-    const db = new Database(contextDbPath(), { readwrite: true });
+    const db = openTestDb(contextDbPath(), { readwrite: true });
     try {
-        db.query("PRAGMA busy_timeout = 5000").run();
         fn(db);
     } finally {
         db.close();
@@ -275,8 +275,7 @@ async function send(sessionId: string, prompt: string, text: string, usage: Mock
             // Open opencode's session DB directly (Database is imported at top of file)
             try {
                 const ocDbPath = join(h.opencode.env.dataDir, "opencode", "opencode.db");
-                const ocDb = new Database(ocDbPath, { readonly: true });
-                ocDb.query("PRAGMA busy_timeout = 1000").run();
+                const ocDb = openTestDb(ocDbPath, { readonly: true });
                 // Get latest messages in the session
                 const rows = ocDb.prepare(
                     "SELECT id, json_extract(data, '$.role') AS role, json_extract(data, '$.finish') AS finish, json_extract(data, '$.summary') AS summary FROM message WHERE session_id = ? ORDER BY id DESC LIMIT 6",
@@ -289,8 +288,7 @@ async function send(sessionId: string, prompt: string, text: string, usage: Mock
                 // Dump parts of the TOP 3 newest messages — reveals source of mystery user messages
                 // (compaction marker? autocontinue text? tool result? synthetic ignored notification?)
                 try {
-                    const ocDb2 = new Database(ocDbPath, { readonly: true });
-                    ocDb2.query("PRAGMA busy_timeout = 1000").run();
+                    const ocDb2 = openTestDb(ocDbPath, { readonly: true });
                     const topIds = rows.slice(0, 3).map((r) => r.id);
                     for (const msgId of topIds) {
                         const parts = ocDb2.prepare(

packages/e2e-tests/tests/memory-injection.test.ts

@@ -11,6 +11,7 @@ import { TestHarness } from "../src/harness";
 // test aligned with whatever the plugin does at runtime.
 import { resolveProjectIdentity } from "../../plugin/src/features/magic-context/memory/project-identity";
 import { computeNormalizedHash } from "../../plugin/src/features/magic-context/memory/normalize-hash";
+import { openTestDb } from "../src/test-db";
 
 /**
  * Memory injection — regression test for v0.9.1.
@@ -61,7 +62,7 @@ function computeDirIdentity(directory: string): string {
 function seedMemory(h: TestHarness, projectIdentity: string, content: string): void {
     // Plugin v0.16+ — shared cortexkit/magic-context path.
     const dbPath = join(h.opencode.env.dataDir, "cortexkit", "magic-context", "context.db");
-    const db = new Database(dbPath);
+    const db = openTestDb(dbPath);
     try {
         const now = Date.now();
         // Use the production hash helper so this matches the value the plugin

packages/e2e-tests/tests/pi-cache-stability.test.ts

@@ -5,6 +5,7 @@ import { describe, expect, it } from "bun:test";
 import { writeFileSync } from "node:fs";
 import { join } from "node:path";
 import { PiTestHarness } from "../src/pi-harness";
+import { openTestDb } from "../src/test-db";
 
 interface HarnessOptions {
     magicContextConfig?: Record<string, unknown>;
@@ -24,11 +25,11 @@ async function withPiHarness<T>(
 }
 
 function openWritableDb(h: PiTestHarness): Database {
-    return new Database(h.contextDbPath(), { readwrite: true });
+    return openTestDb(h.contextDbPath(), { readwrite: true });
 }
 
 function readDb<T>(h: PiTestHarness, fn: (db: Database) => T): T {
-    const db = new Database(h.contextDbPath(), { readonly: true });
+    const db = openTestDb(h.contextDbPath(), { readonly: true });
     try {
         return fn(db);
     } finally {

packages/e2e-tests/tests/pi-cross-harness.test.ts

@@ -8,6 +8,7 @@ import { computeNormalizedHash } from "../../plugin/src/features/magic-context/m
 import { resolveProjectIdentity } from "../../plugin/src/features/magic-context/memory/project-identity";
 import { TestHarness } from "../src/harness";
 import { PiTestHarness } from "../src/pi-harness";
+import { openTestDb } from "../src/test-db";
 
 let oc: TestHarness | null = null;
 let pi: PiTestHarness | null = null;
@@ -20,9 +21,8 @@ afterAll(async () => {
 async function insertMemory(dbPath: string, projectIdentity: string, sessionId: string | null, content: string) {
     const deadline = Date.now() + 10_000;
     while (true) {
-        const db = new Database(dbPath);
+        const db = openTestDb(dbPath);
         try {
-            db.exec("PRAGMA busy_timeout = 1000");
             const now = Date.now();
             db.prepare(
                 `INSERT INTO memories (

packages/e2e-tests/tests/pi-deferred-compaction-marker.test.ts

@@ -5,6 +5,7 @@ import { describe, expect, it } from "bun:test";
 import { existsSync, readFileSync, readdirSync, statSync } from "node:fs";
 import { join } from "node:path";
 import { PiTestHarness } from "../src/pi-harness";
+import { openTestDb } from "../src/test-db";
 
 /**
  * Pi compaction marker behavior (Phase 2 deferred-marker design).
@@ -78,7 +79,7 @@ function findOrdinalRange(body: Record<string, unknown>): { start: number; end:
 }
 
 function readMarkerRow(h: PiTestHarness, sessionId: string): MarkerRow | null {
-    const db = new Database(h.contextDbPath(), { readonly: true });
+    const db = openTestDb(h.contextDbPath(), { readonly: true });
     try {
         return db
             .prepare(
@@ -126,7 +127,7 @@ function readCompactionEntries(h: PiTestHarness): Array<Record<string, unknown>>
  * a reliable indicator that the publish transaction committed.
  */
 function readCompartmentCount(h: PiTestHarness, sessionId: string): number {
-    const db = new Database(h.contextDbPath(), { readonly: true });
+    const db = openTestDb(h.contextDbPath(), { readonly: true });
     try {
         const row = db
             .prepare(

packages/e2e-tests/tests/pi-drops.test.ts

@@ -3,6 +3,7 @@
 import { Database } from "bun:sqlite";
 import { afterAll, beforeAll, describe, expect, it } from "bun:test";
 import { PiTestHarness } from "../src/pi-harness";
+import { openTestDb } from "../src/test-db";
 
 let h: PiTestHarness;
 
@@ -38,7 +39,7 @@ describe("pi drops", () => {
         expect(first.sessionId).toBeTruthy();
         await h.waitFor(() => h.countTags(first.sessionId!) > 0, { label: "tag ready" });
 
-        const writable = new Database(h.contextDbPath());
+        const writable = openTestDb(h.contextDbPath());
         try {
             writable
                 .prepare(

packages/e2e-tests/tests/pi-long-running-session.test.ts

@@ -9,6 +9,7 @@ import { resolveProjectIdentity } from "../../plugin/src/features/magic-context/
 import { computeSyntheticCallId } from "../../plugin/src/hooks/magic-context/todo-view";
 import { PiTestHarness } from "../src/pi-harness";
 import type { MockUsage } from "../src/mock-provider/server";
+import { openTestDb } from "../src/test-db";
 
 const HISTORIAN_SYSTEM_MARKER = "the hippocampus of a long-running coding agent";
 
@@ -155,9 +156,8 @@ function readMeta<T>(h: PiTestHarness, sessionId: string, columns: string): T |
 }
 
 function writeDb(h: PiTestHarness, fn: (db: Database) => void): void {
-    const db = new Database(h.contextDbPath(), { readwrite: true });
+    const db = openTestDb(h.contextDbPath(), { readwrite: true });
     try {
-        db.query("PRAGMA busy_timeout = 5000").run();
         fn(db);
     } finally {
         db.close();

packages/e2e-tests/tests/pi-memory-injection.test.ts

@@ -7,6 +7,7 @@ import { resolve as pathResolve } from "node:path";
 import { computeNormalizedHash } from "../../plugin/src/features/magic-context/memory/normalize-hash";
 import { resolveProjectIdentity } from "../../plugin/src/features/magic-context/memory/project-identity";
 import { PiTestHarness } from "../src/pi-harness";
+import { openTestDb } from "../src/test-db";
 
 let h: PiTestHarness;
 
@@ -19,7 +20,7 @@ afterAll(async () => {
 });
 
 function seedMemory(content: string): void {
-    const db = new Database(h.contextDbPath());
+    const db = openTestDb(h.contextDbPath());
     try {
         const now = Date.now();
         db.prepare(