[schema] implement s.record

Author: dmonad

schema.js

@@ -221,6 +221,40 @@ export class $Object extends $Schema {
  */
 export const object = def => new $Object(def)
 
+/**
+ * @template {$Schema<string|number|symbol>} Keys
+ * @template {$Schema<any>} Values
+ * @extends {$Schema<Record<Keys extends $Schema<infer K> ? K : never,Values extends $Schema<infer T> ? T : never>>}
+ */
+export class $Record extends $Schema {
+  /**
+   * @param {Keys} keys
+   * @param {Values} values
+   */
+  constructor (keys, values) {
+    super()
+    this.keys = keys
+    this.values = values
+  }
+
+  /**
+   * @param {any} o
+   * @return {o is Record<Keys extends $Schema<infer K> ? K : never,Values extends $Schema<infer T> ? T : never>}
+   */
+  check (o) {
+    return o != null && obj.every(o, (vv, vk) => this.keys.check(vk) && this.values.check(vv))
+  }
+}
+
+/**
+ * @template {$Schema<string|number|symbol>} Keys
+ * @template {$Schema<any>} Values
+ * @param {Keys} keys
+ * @param {Values} values
+ * @return {CastToSchema<$Record<Keys,Values>>}
+ */
+export const record = (keys, values) => new $Record(keys, values)
+
 /**
  * @template {$Schema<any>[]} S
  * @extends {$Schema<{ [Key in keyof S]: S[Key] extends $Schema<infer Type> ? Type : never }>}

schema.test.js

@@ -59,6 +59,14 @@ export const testSchemas = _tc => {
     // @ts-expect-error
     t.assert(!myobject.validate(new Date()))
   })
+  t.group('record', () => {
+    const myrecord = s.record(s.number, s.string)
+    // @ts-expect-error
+    t.assert(!myrecord.validate({ a: 'a' }))
+    const myrecord2 = s.record(s.string, s.number)
+    const o = { a: 42 }
+    t.assert(myrecord2.validate(o))
+  })
   t.group('tuple', () => {
     const mytuple = s.tuple(s.number, s.string)
     t.assert(mytuple.validate([4, '5']))

test.html

@@ -154,6 +154,7 @@
   "lib0/performance.js": "./performance.js",
   "lib0/dist/performance.cjs": "./dist/performance.node.cjs",
   "lib0/performance": "./performance.js",
+  "lib0/schema": "./schema.js",
   "isomorphic.js": "./node_modules/isomorphic.js/browser.mjs",
   "isomorphic.js/package.json": "./node_modules/isomorphic.js/package.json"
 },