feat: add base256emoji (#187)

Ref: multiformats/multibase#88

Author: rvagg

README.md

@@ -196,6 +196,8 @@ import the ones you need yourself.
 `base64`, `base64pad`, `base64url`, `base64urlpad` | `multiformats/bases/base64` | [multiformats/js-multiformats](https://github.com/multiformats/js-multiformats/tree/master/bases) |
 `base58btc`, `base58flick4` | `multiformats/bases/base58` | [multiformats/js-multiformats](https://github.com/multiformats/js-multiformats/tree/master/bases) |
 
+Other (less useful) bases implemented in [multiformats/js-multiformats](https://github.com/multiformats/js-multiformats/tree/master/bases) include: `base2`, `base8`, `base10`, `base36` and `base256emoji`.
+
 ### Multihash hashers
 
 | hashes | import | repo |

package.json

@@ -80,6 +80,9 @@
     "./bases/base64": {
       "import": "./src/bases/base64.js"
     },
+    "./bases/base256emoji": {
+      "import": "./src/bases/base256emoji.js"
+    },
     "./hashes/hasher": {
       "import": "./src/hashes/hasher.js"
     },

src/bases/base.js

@@ -84,6 +84,12 @@ class Decoder {
   constructor (name, prefix, baseDecode) {
     this.name = name
     this.prefix = prefix
+    /* c8 ignore next 3 */
+    if (prefix.codePointAt(0) === undefined) {
+      throw new Error('Invalid prefix character')
+    }
+    /** @private */
+    this.prefixCodePoint = /** @type {number} */ (prefix.codePointAt(0))
     this.baseDecode = baseDecode
   }
 
@@ -92,14 +98,10 @@ class Decoder {
    */
   decode (text) {
     if (typeof text === 'string') {
-      switch (text[0]) {
-        case this.prefix: {
-          return this.baseDecode(text.slice(1))
-        }
-        default: {
-          throw Error(`Unable to decode multibase string ${JSON.stringify(text)}, ${this.name} decoder only supports inputs prefixed with ${this.prefix}`)
-        }
+      if (text.codePointAt(0) !== this.prefixCodePoint) {
+        throw Error(`Unable to decode multibase string ${JSON.stringify(text)}, ${this.name} decoder only supports inputs prefixed with ${this.prefix}`)
       }
+      return this.baseDecode(text.slice(this.prefix.length))
     } else {
       throw Error('Can only multibase decode strings')
     }

src/bases/base256emoji.js

@@ -0,0 +1,39 @@
+import { from } from './base.js'
+
+const alphabet = Array.from('🚀🪐☄🛰🌌🌑🌒🌓🌔🌕🌖🌗🌘🌍🌏🌎🐉☀💻🖥💾💿😂❤😍🤣😊🙏💕😭😘👍😅👏😁🔥🥰💔💖💙😢🤔😆🙄💪😉☺👌🤗💜😔😎😇🌹🤦🎉💞✌✨🤷😱😌🌸🙌😋💗💚😏💛🙂💓🤩😄😀🖤😃💯🙈👇🎶😒🤭❣😜💋👀😪😑💥🙋😞😩😡🤪👊🥳😥🤤👉💃😳✋😚😝😴🌟😬🙃🍀🌷😻😓⭐✅🥺🌈😈🤘💦✔😣🏃💐☹🎊💘😠☝😕🌺🎂🌻😐🖕💝🙊😹🗣💫💀👑🎵🤞😛🔴😤🌼😫⚽🤙☕🏆🤫👈😮🙆🍻🍃🐶💁😲🌿🧡🎁⚡🌞🎈❌✊👋😰🤨😶🤝🚶💰🍓💢🤟🙁🚨💨🤬✈🎀🍺🤓😙💟🌱😖👶🥴▶➡❓💎💸⬇😨🌚🦋😷🕺⚠🙅😟😵👎🤲🤠🤧📌🔵💅🧐🐾🍒😗🤑🌊🤯🐷☎💧😯💆👆🎤🙇🍑❄🌴💣🐸💌📍🥀🤢👅💡💩👐📸👻🤐🤮🎼🥵🚩🍎🍊👼💍📣🥂')
+const alphabetBytesToChars = /** @type {string[]} */ (alphabet.reduce((p, c, i) => { p[i] = c; return p }, /** @type {string[]} */([])))
+const alphabetCharsToBytes = /** @type {number[]} */ (alphabet.reduce((p, c, i) => { p[/** @type {number} */ (c.codePointAt(0))] = i; return p }, /** @type {number[]} */([])))
+
+/**
+ * @param {Uint8Array} data
+ * @returns {string}
+ */
+function encode (data) {
+  return data.reduce((p, c) => {
+    p += alphabetBytesToChars[c]
+    return p
+  }, '')
+}
+
+/**
+ * @param {string} str
+ * @returns {Uint8Array}
+ */
+function decode (str) {
+  const byts = []
+  for (const char of str) {
+    const byt = alphabetCharsToBytes[/** @type {number} */ (char.codePointAt(0))]
+    if (byt === undefined) {
+      throw new Error(`Non-base256emoji character: ${char}`)
+    }
+    byts.push(byt)
+  }
+  return new Uint8Array(byts)
+}
+
+export const base256emoji = from({
+  prefix: '🚀',
+  name: 'base256emoji',
+  encode,
+  decode
+})

src/basics.js

@@ -9,6 +9,7 @@ import * as base32 from './bases/base32.js'
 import * as base36 from './bases/base36.js'
 import * as base58 from './bases/base58.js'
 import * as base64 from './bases/base64.js'
+import * as base256emoji from './bases/base256emoji.js'
 import * as sha2 from './hashes/sha2.js'
 import * as identity from './hashes/identity.js'
 
@@ -17,7 +18,7 @@ import * as json from './codecs/json.js'
 
 import { CID, hasher, digest, varint, bytes } from './index.js'
 
-const bases = { ...identityBase, ...base2, ...base8, ...base10, ...base16, ...base32, ...base36, ...base58, ...base64 }
+const bases = { ...identityBase, ...base2, ...base8, ...base10, ...base16, ...base32, ...base36, ...base58, ...base64, ...base256emoji }
 const hashes = { ...sha2, ...identity }
 const codecs = { raw, json }
 

test/test-multibase-spec.js

@@ -35,7 +35,8 @@ const encoded = [
       ['base64', 'mRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchIQ'],
       ['base64pad', 'MRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchIQ=='],
       ['base64url', 'uRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchIQ'],
-      ['base64urlpad', 'URGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchIQ==']
+      ['base64urlpad', 'URGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchIQ=='],
+      ['base256emoji', '🚀💛✋💃✋😻😈🥺🤤🍀🌟💐✋😅✋💦✋🥺🏃😈😴🌟😻😝👏👏']
     ]
   },
   {
@@ -63,7 +64,8 @@ const encoded = [
       ['base64', 'meWVzIG1hbmkgIQ'],
       ['base64pad', 'MeWVzIG1hbmkgIQ=='],
       ['base64url', 'ueWVzIG1hbmkgIQ'],
-      ['base64urlpad', 'UeWVzIG1hbmkgIQ==']
+      ['base64urlpad', 'UeWVzIG1hbmkgIQ=='],
+      ['base256emoji', '🚀🏃✋🌈😅🌷🤤😻🌟😅👏']
     ]
   },
   {
@@ -91,7 +93,8 @@ const encoded = [
       ['base64', 'maGVsbG8gd29ybGQ'],
       ['base64pad', 'MaGVsbG8gd29ybGQ='],
       ['base64url', 'uaGVsbG8gd29ybGQ'],
-      ['base64urlpad', 'UaGVsbG8gd29ybGQ=']
+      ['base64urlpad', 'UaGVsbG8gd29ybGQ='],
+      ['base256emoji', '🚀😴✋🍀🍀😓😅✔😓🥺🍀😳']
     ]
   },
   {
@@ -119,7 +122,8 @@ const encoded = [
       ['base64', 'mAHllcyBtYW5pICE'],
       ['base64pad', 'MAHllcyBtYW5pICE='],
       ['base64url', 'uAHllcyBtYW5pICE'],
-      ['base64urlpad', 'UAHllcyBtYW5pICE=']
+      ['base64urlpad', 'UAHllcyBtYW5pICE='],
+      ['base256emoji', '🚀🚀🏃✋🌈😅🌷🤤😻🌟😅👏']
     ]
   },
   {
@@ -147,24 +151,8 @@ const encoded = [
       ['base64', 'mAAB5ZXMgbWFuaSAh'],
       ['base64pad', 'MAAB5ZXMgbWFuaSAh'],
       ['base64url', 'uAAB5ZXMgbWFuaSAh'],
-      ['base64urlpad', 'UAAB5ZXMgbWFuaSAh']
-    ]
-  },
-  {
-    input: 'hello world',
-    tests: [
-      ['base16', 'f68656c6c6f20776f726c64'],
-      ['base16upper', 'F68656C6C6F20776F726C64'],
-      ['base32', 'bnbswy3dpeb3w64tmmq'],
-      ['base32upper', 'BNBSWY3DPEB3W64TMMQ'],
-      ['base32hex', 'vd1imor3f41rmusjccg'],
-      ['base32hexupper', 'VD1IMOR3F41RMUSJCCG'],
-      ['base32pad', 'cnbswy3dpeb3w64tmmq======'],
-      ['base32padupper', 'CNBSWY3DPEB3W64TMMQ======'],
-      ['base32hexpad', 'td1imor3f41rmusjccg======'],
-      ['base32hexpadupper', 'TD1IMOR3F41RMUSJCCG======'],
-      ['base36', 'kfuvrsivvnfrbjwajo'],
-      ['base36upper', 'KFUVRSIVVNFRBJWAJO']
+      ['base64urlpad', 'UAAB5ZXMgbWFuaSAh'],
+      ['base256emoji', '🚀🚀🚀🏃✋🌈😅🌷🤤😻🌟😅👏']
     ]
   }
 ]
@@ -196,7 +184,6 @@ describe('spec test', () => {
         return this.skip()
       }
 
-      console.info('expect', `Non-${base.name} character`)
       assert.throws(() => base.decode(base.prefix + '^!@$%!#$%@#y'), `Non-${base.name} character`)
     })
   }

test/test-traversal.js

@@ -163,7 +163,7 @@ describe('traversal', () => {
       /** @type {[]} */
       const links = []
       const value = createNode(fromString('test'), links)
-      const block = await main.encode({ value: value, codec, hasher })
+      const block = await main.encode({ value, codec, hasher })
       const cid = block.cid
       const expectedCallArray = [cid.toString()]
       /** @type {string[]} */