reduce bundlesize by moving from while to reduce (#355)

* reduce bundlesize by moving from while to reduce

* reduce bundlesize for brotli by symbols reusing

index.browser.js

@@ -47,31 +47,26 @@ let customRandom = (alphabet, defaultSize, getRandom) => {
 let customAlphabet = (alphabet, size = 21) =>
   customRandom(alphabet, size, random)
 
-let nanoid = (size = 21) => {
-  let id = ''
-  let bytes = crypto.getRandomValues(new Uint8Array(size))
-
-  // A compact alternative for `for (var i = 0; i < step; i++)`.
-  while (size--) {
+let nanoid = (size = 21) =>
+  crypto.getRandomValues(new Uint8Array(size)).reduce((id, byte) => {
     // It is incorrect to use bytes exceeding the alphabet size.
     // The following mask reduces the random byte in the 0-255 value
     // range to the 0-63 value range. Therefore, adding hacks, such
     // as empty string fallback or magic numbers, is unneccessary because
     // the bitmask trims bytes down to the alphabet size.
-    let byte = bytes[size] & 63
+    byte &= 63
     if (byte < 36) {
       // `0-9a-z`
       id += byte.toString(36)
     } else if (byte < 62) {
       // `A-Z`
       id += (byte - 26).toString(36).toUpperCase()
-    } else if (byte < 63) {
-      id += '_'
-    } else {
+    } else if (byte > 62) {
       id += '-'
+    } else {
+      id += '_'
     }
-  }
-  return id
-}
+    return id
+  }, '')
 
 module.exports = { nanoid, customAlphabet, customRandom, urlAlphabet, random }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "nanoid",
   "version": "3.3.2",
-  "description": "A tiny (130 bytes), secure URL-friendly unique string ID generator",
+  "description": "A tiny (116 bytes), secure URL-friendly unique string ID generator",
   "keywords": [
     "uuid",
     "random",
@@ -68,7 +68,7 @@
     {
       "name": "nanoid",
       "import": "{ nanoid }",
-      "limit": "130 B"
+      "limit": "116 B"
     },
     {
       "name": "customAlphabet",
@@ -108,7 +108,7 @@
       "name": "Brotli all",
       "brotli": true,
       "import": "{ nanoid, customAlphabet, urlAlphabet }",
-      "limit": "271 B"
+      "limit": "260 B"
     },
     {
       "name": "Brotli non-secure",