feat(encoding/unstable): Crockford base32 unstable support (#6238)

encoding/deno.json

@@ -6,6 +6,7 @@
     "./ascii85": "./ascii85.ts",
     "./base32": "./base32.ts",
     "./unstable-base32-stream": "./unstable_base32_stream.ts",
+    "./unstable-base32crockford": "./unstable_base32crockford.ts",
     "./unstable-base32hex": "./unstable_base32hex.ts",
     "./unstable-base32hex-stream": "./unstable_base32hex_stream.ts",
     "./base58": "./base58.ts",

encoding/unstable_base32crockford.ts

@@ -0,0 +1,75 @@
+// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
+// Copyright (c) 2014 Jameson Little. MIT License.
+// This module is browser compatible.
+
+/**
+ * Utilities for
+ * {@link https://www.crockford.com/base32.html | Crockford base32}
+ * encoding and decoding.
+ *
+ * Modified from @std/encoding/base32.
+ *
+ * ```ts
+ * import { encodeBase32Crockford, decodeBase32Crockford } from "@std/encoding/unstable-base32crockford";
+ * import { assertEquals } from "@std/assert";
+ *
+ * assertEquals(encodeBase32Crockford("foobar"), "CSQPYRK1E8======");
+ *
+ * assertEquals(
+ *   decodeBase32Crockford("CSQPYRK1E8======"),
+ *   new TextEncoder().encode("foobar")
+ * );
+ * ```
+ *
+ * @module
+ */
+import { decode, encode } from "./_base32_common.ts";
+
+const lookup: string[] = "0123456789ABCDEFGHJKMNPQRSTVWXYZ".split("");
+const revLookup: number[] = [];
+lookup.forEach((c, i) => (revLookup[c.charCodeAt(0)] = i));
+
+/**
+ * Decodes a Crockford base32-encoded string.
+ *
+ * @see {@link https://www.crockford.com/base32.html}
+ *
+ * @param b32 The Crockford Base32-encoded string to decode.
+ * @returns The decoded data.
+ *
+ * @example Usage
+ * ```ts
+ * import { decodeBase32Crockford } from "@std/encoding/unstable-base32crockford";
+ * import { assertEquals } from "@std/assert";
+ *
+ * assertEquals(
+ *   decodeBase32Crockford("CSQPYRK1E8======"),
+ *   new TextEncoder().encode("foobar")
+ * );
+ * ```
+ */
+export function decodeBase32Crockford(b32: string): Uint8Array {
+  return decode(b32, lookup);
+}
+
+/**
+ * Converts data into a Crockford base32-encoded string.
+ *
+ * @see {@link https://www.crockford.com/base32.html}
+ *
+ * @param data The data to encode.
+ * @returns The Crockford base32-encoded string.
+ *
+ * @example Usage
+ * ```ts
+ * import { encodeBase32Crockford } from "@std/encoding/unstable-base32crockford";
+ * import { assertEquals } from "@std/assert";
+ *
+ * assertEquals(encodeBase32Crockford("foobar"), "CSQPYRK1E8======");
+ * ```
+ */
+export function encodeBase32Crockford(
+  data: ArrayBuffer | Uint8Array | string,
+): string {
+  return encode(data, lookup);
+}

encoding/unstable_base32crockford_test.ts

@@ -0,0 +1,67 @@
+// Test cases copied from https://github.com/LinusU/base32-encode/blob/master/test.js
+// Copyright (c) 2016-2017 Linus Unnebäck. MIT license.
+// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
+import { assertEquals, assertExists, assertThrows } from "@std/assert";
+import {
+  decodeBase32Crockford,
+  encodeBase32Crockford,
+} from "./unstable_base32crockford.ts";
+
+// Test vectors from https://www.rfc-editor.org/rfc/rfc4648.html#section-10
+const testCases = [
+  ["", ""],
+  ["f", "CR======"],
+  ["fo", "CSQG===="],
+  ["foo", "CSQPY==="],
+  ["foob", "CSQPYRG="],
+  ["fooba", "CSQPYRK1"],
+  ["foobar", "CSQPYRK1E8======"],
+] as const;
+
+Deno.test({
+  name: "encodeBase32()",
+  fn() {
+    for (const [bin, b32] of testCases) {
+      assertEquals(encodeBase32Crockford(bin), b32);
+    }
+  },
+});
+
+Deno.test({
+  name: "decodeBase32()",
+  fn() {
+    for (const [bin, b32] of testCases) {
+      assertEquals(decodeBase32Crockford(b32), new TextEncoder().encode(bin));
+    }
+  },
+});
+
+Deno.test({
+  name: "decodeBase32() throws on bad length",
+  fn() {
+    assertThrows(
+      () => decodeBase32Crockford("OOOO=="),
+      Error,
+      "Cannot decode base32 string as the length must be a multiple of 8: received length 6",
+    );
+  },
+});
+
+Deno.test({
+  name: "decodeBase32() throws on bad padding",
+  fn() {
+    assertThrows(
+      () => decodeBase32Crockford("5HXR334AQYAAAA=="),
+      Error,
+      "Invalid pad length",
+    );
+  },
+});
+
+Deno.test({
+  name: "encodeBase32() encodes very long text",
+  fn() {
+    const data = "a".repeat(16400);
+    assertExists(encodeBase32Crockford(data));
+  },
+});