feat: b64urlFromBuffer()

Encode to URL-safe base64, from ArrayBuffer or Uint8Array

Author: waitingsong

package.json

@@ -2,9 +2,10 @@
   "name": "@waiting/base64",
   "author": "waiting",
   "version": "4.1.0",
-  "description": "Base64 encoding/decoding in pure JS on both modern Browsers and Node.js",
+  "description": "Base64 encoding/decoding in pure JS on both modern Browsers and Node.js. Also supports URL-safe base64",
   "keywords": [
     "base64",
+    "URL-safe",
     "browser",
     "Node.js",
     "rfc4648",

src/lib/index.ts

@@ -81,6 +81,17 @@ export function b64urlEncode(
 }
 
 
+/**
+ * Encode to URL-safe base64, source from ArrayBuffer or Uint8Array
+ *
+ * @see https://en.wikipedia.org/wiki/Base64#URL_applications
+ */
+export function b64urlFromBuffer(buffer: ArrayBuffer | Uint8Array): string {
+  const b64 = b64fromBuffer(buffer)
+  return b64toURLSafe(b64)
+}
+
+
 /**
  * Decode URL-safe base64 to original string.
  *

test/10_index.test.ts

@@ -9,10 +9,21 @@ import * as assert from 'power-assert'
 import rewire = require('rewire')
 import { TextDecoder, TextEncoder } from 'util'
 
-import { b64decode, b64encode, b64fromBuffer, b64urlDecode, b64urlEncode } from '../src/index'
+import { b64decode, b64encode, b64fromBuffer, b64urlDecode, b64urlEncode, b64urlFromBuffer } from '../src/index'
 import { defaultConfig, ErrMsg } from '../src/lib/config'
 
-import { input1, input2, input3, input4, input44, input5, input8, inputURLSafe, inputURLSafe2 } from './config'
+import {
+  input1,
+  input2,
+  input3,
+  input4,
+  input44,
+  input5,
+  input8,
+  inputURLSafe,
+  inputURLSafe2,
+  inputURLSafe3,
+} from './config'
 
 
 const filename = basename(__filename)
@@ -89,6 +100,7 @@ describe(filename, () => {
         assert(actual === expected, `Ensure that ${u8arr} serialise to ${expected}`)
       })
     })
+
   })
 
 
@@ -141,4 +153,20 @@ describe(filename, () => {
   })
 
 
+  describe('Should b64urlFromBuffer() works', () => {
+    it('with valid input', () => {
+      inputURLSafe3.forEach(row => {
+        const u8arr = Uint8Array.from(row[0])
+        const ret = b64urlFromBuffer(u8arr);
+
+        [...ret].forEach((ch, idx) => {
+          const expect = row[1][idx]
+          assert(expect === ch, `${expect}, ${ch}, ${idx}`)
+        })
+      })
+    })
+
+  })
+
+
 })

test/config.ts

@@ -115,7 +115,6 @@ export const input8: Input8Item[] = [
   [ [0xe4, 0xb8, 0xad, 0xe6, 0x96, 0x87], '5Lit5paH'],
 ]
 
-
 export const input9 = [
   ' ',
   '*',
@@ -207,3 +206,7 @@ export const inputBase64URLInvalid = [
   'Q',
   'AABB\nAABB',
 ]
+
+export const inputURLSafe3: Array<[number[], string]> = [
+  [ [0xff, 0xff, 0xbe, 0xff, 0xef, 0xbf, 0xfb, 0xef, 0xff], '__--_--_--__'],
+]