feat: add TakeLimitError and DropLimitError

Author: lambdalisue

drop.ts

@@ -16,10 +16,8 @@
  * ```
  */
 export function drop<T>(iterable: Iterable<T>, limit: number): Iterable<T> {
-  if (limit < 0) {
-    throw new Error(
-      `limit argument must be greater than or equal to 0, but got ${limit}.`,
-    );
+  if (limit < 0 || !Number.isSafeInteger(limit)) {
+    throw new DropLimitError(limit);
   }
   return function* () {
     let i = 0;
@@ -30,3 +28,12 @@ export function drop<T>(iterable: Iterable<T>, limit: number): Iterable<T> {
     }
   }();
 }
+
+/**
+ * Error thrown when the 'limit' is negative or not a safe integer.
+ */
+export class DropLimitError extends Error {
+  constructor(limit: number) {
+    super(`The 'limit' must be 0 or positive safe integer, but got ${limit}.`);
+  }
+}

drop_test.ts

@@ -1,6 +1,6 @@
 import { assertEquals, assertThrows } from "@std/assert";
 import { assertType, type IsExact } from "@std/testing/types";
-import { drop } from "./drop.ts";
+import { drop, DropLimitError } from "./drop.ts";
 
 Deno.test("drop", async (t) => {
   await t.step("with positive limit", () => {
@@ -15,8 +15,7 @@ Deno.test("drop", async (t) => {
       () => {
         drop([0, 1, 2, 3, 4], -2);
       },
-      Error,
-      "limit argument must be greater than or equal to 0, but got -2.",
+      DropLimitError,
     );
   });
 

take.ts

@@ -16,10 +16,8 @@
  * ```
  */
 export function take<T>(iterable: Iterable<T>, limit: number): Iterable<T> {
-  if (limit < 0) {
-    throw new Error(
-      `limit argument must be greater than or equal to 0, but got ${limit}.`,
-    );
+  if (limit < 0 || !Number.isSafeInteger(limit)) {
+    throw new TakeLimitError(limit);
   }
   return function* () {
     let i = 0;
@@ -31,3 +29,12 @@ export function take<T>(iterable: Iterable<T>, limit: number): Iterable<T> {
     }
   }();
 }
+
+/**
+ * Error thrown when the 'limit' is negative or not a safe integer.
+ */
+export class TakeLimitError extends Error {
+  constructor(limit: number) {
+    super(`The 'limit' must be 0 or positive safe integer, but got ${limit}.`);
+  }
+}

take_test.ts

@@ -1,6 +1,6 @@
 import { assertEquals, assertThrows } from "@std/assert";
 import { assertType, type IsExact } from "@std/testing/types";
-import { take } from "./take.ts";
+import { take, TakeLimitError } from "./take.ts";
 
 Deno.test("take", async (t) => {
   await t.step("with positive limit", () => {
@@ -15,8 +15,7 @@ Deno.test("take", async (t) => {
       () => {
         take([0, 1, 2, 3, 4], -2);
       },
-      Error,
-      "limit argument must be greater than or equal to 0, but got -2.",
+      TakeLimitError,
     );
   });