feat(count): improve display format

validators/iterable/count.ts

@@ -4,20 +4,24 @@
 import { getSize } from "./utils.ts";
 import { format, ScalarValidator } from "../../utils.ts";
 import error from "../error.json" assert { type: "json" };
+import plural from "../plural.json" assert { type: "json" };
 
 export class CountValidator extends ScalarValidator<Iterable<unknown>> {
-  constructor(public size: number) {
+  constructor(public count: number) {
     super();
     super.expect(({ input }) =>
       format(error.should_be_but, this, getSize(input))
     );
   }
 
   override is(input: Iterable<unknown>): boolean {
-    return getSize(input) === this.size;
+    return getSize(input) === this.count;
   }
 
   toString(): string {
-    return `number of ${this.size}`;
+    const pr = new Intl.PluralRules("en-US");
+    const suffix = plural[pr.select(this.count)];
+
+    return `${this.count} item${suffix}`;
   }
 }

validators/plural.json

@@ -0,0 +1,8 @@
+{
+  "zero": "",
+  "one": "",
+  "many": "s",
+  "other": "s",
+  "two": "s",
+  "few": "s"
+}