fix: enforce MongoStore constructor asserts (plan#runtime)

Author: mingchuno

docs/PLANS.md

@@ -29,6 +29,8 @@
   - Type safety is paper-thin: option hooks (serialize, transformId, crypto) stay typed as any and defaultSerializeFunction is littered with @ts-ignore (src/lib/MongoStore.ts:61-124). Once you enable the stricter compiler flags below, refactor this class into generics (MongoStore<T extends SessionData>) so public
     types match reality.
     - [done 2025-11-16] Improve type safety with generics/typed hooks (agent: Codex)
+  - Replace console.assert with real assertions: current guards in the constructor use import { assert } from 'console', which only logs and does not throw, so bad options still proceed and fail later. Switch to node:assert/strict to enforce required inputs. src/lib/MongoStore.ts:1,200-214
+    - [done 2025-11-19] Replace console.assert with node:assert/strict and add tests for missing mongoUrl/client options (agent: Codex)
 
 - Tooling & CI
   - Tighten the compiler and target modern runtimes: tsconfig.json still emits ES2018/CommonJS, disables strictFunctionTypes, noImplicitAny, and noUnused*, and forces inline source maps that bloat npm tarballs (tsconfig.json:2-44). Move to target: es2022, enable the strict diagnostics, emit external .map files, and

src/lib/MongoStore.spec.ts

@@ -27,10 +27,33 @@ test.afterEach.always(async () => {
 
 test.serial('create store w/o provide required options', (t) => {
   t.throws(() => MongoStore.create({}), {
-    message: /Cannot init client/,
+    message: /You must provide either mongoUrl\|clientPromise\|client/,
   })
 })
 
+test.serial(
+  'create store with explicit undefined clientPromise still errors',
+  (t) => {
+    t.throws(
+      () =>
+        MongoStore.create({
+          clientPromise: undefined as unknown as Promise<MongoClient>,
+        }),
+      { message: /You must provide either mongoUrl\|clientPromise\|client/ }
+    )
+  }
+)
+
+test.serial('create store with explicit undefined client still errors', (t) => {
+  t.throws(
+    () =>
+      MongoStore.create({
+        client: undefined as unknown as MongoClient,
+      }),
+    { message: /You must provide either mongoUrl\|clientPromise\|client/ }
+  )
+})
+
 test.serial('create store with clientPromise', async (t) => {
   const clientP = MongoClient.connect('mongodb://root:example@127.0.0.1:27017')
   const store = MongoStore.create({ clientPromise: clientP })

src/lib/MongoStore.ts

@@ -1,4 +1,4 @@
-import { assert } from 'console'
+import assert from 'node:assert/strict'
 import util from 'util'
 import * as session from 'express-session'
 import {