chore: add base64url tests

Author: kangmingtay

src/lib/base64url.test.ts

@@ -0,0 +1,77 @@
+import {
+  stringToBase64URL,
+  stringFromBase64URL,
+  stringFromUTF8,
+  codepointToUTF8,
+} from './base64url'
+
+const EXAMPLES = [
+  'a',
+  'ab',
+  'abc',
+  'abcd',
+  'hello world',
+  'нешто на кирилица',
+  'something with emojis 🤙🏾 ',
+  'Supabaseは、オープンソースの Firebase 代替製品です。エンタープライズグレードのオープンソースツールを使って、Firebase の機能を構築しています。',
+]
+
+describe('stringToBase64URL', () => {
+  EXAMPLES.forEach((example) => {
+    test(`encode "${example}"`, () => {
+      expect(stringToBase64URL(example)).toEqual(Buffer.from(example).toString('base64url'))
+    })
+  })
+})
+
+describe('stringFromBase64URL', () => {
+  EXAMPLES.forEach((example) => {
+    test(`decode "${example}"`, () => {
+      expect(stringFromBase64URL('\r\t\n ' + Buffer.from(example).toString('base64url'))).toEqual(
+        example
+      )
+    })
+  })
+
+  test('decode with invalid Base64-URL character', () => {
+    expect(() => {
+      stringFromBase64URL('*')
+    }).toThrow(new Error(`Invalid Base64-URL character "*"`))
+  })
+})
+
+const BAD_UTF8 = [
+  [0xf8], // 11111000
+  [0xff], // 11111111
+  [0x80], // 10000000
+  [0xf8, 1], // 11110000 00000001
+  [0xe0, 1], // 11100000 00000001
+  [0xc0, 1], // 11100000 00000001
+]
+
+describe('stringFromUTF8', () => {
+  BAD_UTF8.forEach((example) => {
+    test(`should recognize bad UTF-8 sequence ${example
+      .map((x) => x.toString(16))
+      .join(' ')}`, () => {
+      expect(() => {
+        const state = { utf8seq: 0, codepoint: 0 }
+        example.forEach((byte) => {
+          // eslint-disable-next-line @typescript-eslint/no-empty-function
+          stringFromUTF8(byte, state, () => {})
+        })
+      }).toThrow(new Error('Invalid UTF-8 sequence'))
+    })
+  })
+})
+
+describe('codepointToUTF8', () => {
+  test('invalid codepoints above 0x10ffff', () => {
+    const invalidCodepoint = 0x10ffff + 1
+    expect(() => {
+      codepointToUTF8(invalidCodepoint, () => {
+        throw new Error('Should not becalled')
+      })
+    }).toThrow(new Error(`Unrecognized Unicode codepoint: ${invalidCodepoint.toString(16)}`))
+  })
+})