fix: replace as-any casts with proper TemporalLike types

Address review feedback from Sam Willis and CodeRabbit:
- Add TemporalLike interface in db-ivm for type-safe Temporal detection
- Make isTemporal a proper type guard (returns input is TemporalLike)
- Remove as-any casts in hashTemporal
- Add return type to createTemporalLike test helper
- Remove unnecessary casts in join regression test

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: KyleAMathews

packages/db-ivm/src/hashing/hash.ts

@@ -31,8 +31,13 @@ const temporalTypes = new Set([
   `Temporal.ZonedDateTime`,
 ])
 
-function isTemporal(input: object): boolean {
-  const tag = (input as any)[Symbol.toStringTag]
+interface TemporalLike {
+  [Symbol.toStringTag]: string
+  toString: () => string
+}
+
+function isTemporal(input: object): input is TemporalLike {
+  const tag = (input as Record<symbol, unknown>)[Symbol.toStringTag]
   return typeof tag === `string` && temporalTypes.has(tag)
 }
 
@@ -122,11 +127,11 @@ function hashUint8Array(input: Uint8Array): number {
   return hasher.digest()
 }
 
-function hashTemporal(input: object): number {
+function hashTemporal(input: TemporalLike): number {
   const hasher = new MurmurHashStream()
   hasher.update(TEMPORAL_MARKER)
-  hasher.update((input as any)[Symbol.toStringTag])
-  hasher.update((input as any).toString())
+  hasher.update(input[Symbol.toStringTag])
+  hasher.update(input.toString())
   return hasher.digest()
 }
 

packages/db-ivm/tests/utils.test.ts

@@ -4,7 +4,10 @@ import { hash } from '../src/hashing/index.js'
 
 // Minimal mock that mimics Temporal objects: Symbol.toStringTag + toString()
 // without requiring the temporal-polyfill dependency.
-function createTemporalLike(tag: string, value: string) {
+function createTemporalLike(
+  tag: string,
+  value: string,
+): { toString: () => string; [Symbol.toStringTag]: string } {
   return Object.create(null, {
     [Symbol.toStringTag]: { value: tag },
     toString: { value: () => value },

packages/db/src/utils.ts

@@ -222,10 +222,16 @@ const temporalTypes = new Set([
   `Temporal.ZonedDateTime`,
 ])
 
+export interface TemporalLike {
+  [Symbol.toStringTag]: string
+  toString: () => string
+  equals?: (other: unknown) => boolean
+}
+
 /** Checks if the value is a Temporal object by checking for the Temporal brand */
-export function isTemporal(a: any): boolean {
+export function isTemporal(a: unknown): a is TemporalLike {
   if (a == null || typeof a !== `object`) return false
-  const tag = a[Symbol.toStringTag]
+  const tag = (a as Record<symbol, unknown>)[Symbol.toStringTag]
   return typeof tag === `string` && temporalTypes.has(tag)
 }
 

packages/db/tests/query/join.test.ts

@@ -2086,18 +2086,14 @@ function createJoinTests(autoIndex: `off` | `eager`): void {
 
     await liveQuery.preload()
     expect(liveQuery.toArray).toHaveLength(1)
-    expect(
-      (liveQuery.toArray[0]!.task.dueDate as Temporal.PlainDate).toString(),
-    ).toBe(`2024-01-15`)
+    expect(String(liveQuery.toArray[0]!.task.dueDate)).toBe(`2024-01-15`)
 
-    taskCollection.update(1, (draft) => {
-      ;(draft as any).dueDate = Temporal.PlainDate.from(`2024-06-15`)
+    taskCollection.update(1, (draft: Task) => {
+      draft.dueDate = Temporal.PlainDate.from(`2024-06-15`)
     })
     await flushPromises()
 
-    expect(
-      (liveQuery.toArray[0]!.task.dueDate as Temporal.PlainDate).toString(),
-    ).toBe(`2024-06-15`)
+    expect(String(liveQuery.toArray[0]!.task.dueDate)).toBe(`2024-06-15`)
   })
 }