feat(lte): add validator for less than or equal operator

Author: TomokiMiyauci

combinator.ts

@@ -18,6 +18,7 @@ import { NonEmptyValidator } from "./validators/iterable/non_empty.ts";
 import { AndValidator } from "./validators/operators/and.ts";
 import { EqualityValidator } from "./validators/operators/eq.ts";
 import { LessThenValidator } from "./validators/operators/lt.ts";
+import { LessThenOrEqualValidator } from "./validators/operators/lte.ts";
 import { GreaterThenValidator } from "./validators/operators/gt.ts";
 import { GreaterThenOrEqualValidator } from "./validators/operators/gte.ts";
 import { TypeValidator } from "./validators/operators/typeof.ts";
@@ -35,6 +36,7 @@ export const optional = /* @__PURE__ */ lazy(OptionalValidator);
 export const nullish = /* @__PURE__ */ new NullishValidator();
 export const eq = /* @__PURE__ */ lazy(EqualityValidator);
 export const lt = /* @__PURE__ */ lazy(LessThenValidator);
+export const lte = /* @__PURE__ */ lazy(LessThenOrEqualValidator);
 export const gt = /* @__PURE__ */ lazy(GreaterThenValidator);
 export const gte = /* @__PURE__ */ lazy(GreaterThenOrEqualValidator);
 export const and = /* @__PURE__ */ lazy(AndValidator);

mod.ts

@@ -15,6 +15,7 @@ export {
   int,
   item,
   lt,
+  lte,
   maxCount,
   minCount,
   nonEmpty,

validators/operators/lte.ts

@@ -0,0 +1,20 @@
+// Copyright 2023-latest Tomoki Miyauchi. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { ScalarValidator } from "../../utils.ts";
+import { shouldBeBut } from "../utils.ts";
+
+export class LessThenOrEqualValidator<In> extends ScalarValidator<In> {
+  constructor(public base: In) {
+    super();
+    super.expect(shouldBeBut);
+  }
+
+  override is(input: In): input is In {
+    return input <= this.base;
+  }
+
+  override toString(): string {
+    return `<= ${this.base}`;
+  }
+}