Split NodeJS and browser setup

bls-demo.js

@@ -1,3 +1,10 @@
+// Get random source
+const crypto = window.crypto || window.msCrypto
+const getRandomValues = x => crypto.getRandomValues(x)
+// Setup BLS
+const bls = {}
+blsSetupFactory(createBlsModule, getRandomValues, bls)
+
 function getValue (name) { return document.getElementsByName(name)[0].value }
 function setValue (name, val) { document.getElementsByName(name)[0].value = val }
 function getText (name) { return document.getElementsByName(name)[0].innerText }

bls.js

@@ -1,11 +1,10 @@
-(generator => {
-  if (typeof window === 'object') {
-    const exports = {}
-    window.bls = generator(exports, false)
-  } else {
-    generator(exports, true)
-  }
-})((exports, isNodeJs) => {
+/**
+ * @param createBlsModule Async factory that returns an emcc initialized Module
+ * In node, `const createBlsModule = require(`./bls_c.js`)`
+ * @param getRandomValues Function to get crypto quality random values
+ * @param exports Reference to an object to fill BLS methods
+ */
+function blsSetupFactory(createBlsModule, getRandomValues, exports) {
   /* eslint-disable */
   exports.BN254 = 0
   exports.BN381_1 = 1
@@ -15,7 +14,7 @@
   exports.ETH_MODE_DRAFT_06 = 2
   exports.ETH_MODE_DRAFT_07 = 3
 
-  const setup = (exports, curveType) => {
+  function blsSetup(exports, curveType) {
     const mod = exports.mod
     const MCLBN_FP_UNIT_SIZE = 6
     const MCLBN_FR_UNIT_SIZE = exports.ethMode ? 4 : 6
@@ -630,7 +629,8 @@
     if (exports.ethMode) {
       exports.setETHmode(exports.ETH_MODE_DRAFT_07)
     }
-  } // setup()
+  } // blsSetup()
+
   const _cryptoGetRandomValues = function(p, n) {
     const a = new Uint8Array(n)
     exports.getRandomValues(a)
@@ -642,41 +642,26 @@
   exports.setRandFunc = f => {
     exports.getRandomValues = f
   }
-  exports.init = (curveType = exports.BN254) => {
+  exports.init = async (curveType = exports.BN254) => {
     exports.curveType = curveType
-    const name = 'bls_c'
-    return new Promise(resolve => {
-      if (isNodeJs) {
-        const crypto = require('crypto')
-        exports.getRandomValues = crypto.randomFillSync
-        const path = require('path')
-        const js = require(`./${name}.js`)
-        const Module = {
-          cryptoGetRandomValues : _cryptoGetRandomValues,
-          locateFile: baseName => { return path.join(__dirname, baseName) }
-        }
-        js(Module)
-          .then(_mod => {
-            exports.mod = _mod
-            setup(exports, curveType)
-            resolve()
-          })
-      } else {
-        const crypto = window.crypto || window.msCrypto
-        exports.getRandomValues = x => crypto.getRandomValues(x)
-        fetch(`./${name}.wasm`) // eslint-disable-line
-          .then(response => response.arrayBuffer())
-          .then(buffer => new Uint8Array(buffer))
-          .then(() => {
-            exports.mod = Module() // eslint-disable-line
-            exports.mod.cryptoGetRandomValues = _cryptoGetRandomValues
-            exports.mod.onRuntimeInitialized = () => {
-              setup(exports, curveType)
-              resolve()
-            }
-          })
-      }
+    exports.getRandomValues = getRandomValues;
+    exports.mod = await createBlsModule({
+      cryptoGetRandomValues: _cryptoGetRandomValues,
     })
+    blsSetup(exports, curveType)
   }
   return exports
-})
+}
+
+// NodeJS export
+if (typeof exports === 'object' && typeof module === 'object')
+  module.exports = blsSetupFactory;
+else if (typeof define === 'function' && define['amd'])
+  define([], function() { return blsSetupFactory; });
+else if (typeof exports === 'object')
+  exports["blsSetupFactory"] = blsSetupFactory;
+
+// Browser export
+if (typeof window === 'object') {
+  window.blsSetupFactory = blsSetupFactory;
+}

index.js

@@ -0,0 +1,10 @@
+const crypto = require('crypto')
+const createBlsModule = require(`./bls_c.js`)
+const blsSetupFactory = require('./bls')
+
+const bls = {}
+
+const getRandomValues = crypto.randomFillSync
+blsSetupFactory(createBlsModule, getRandomValues, bls)
+
+module.exports = bls;

test.js

@@ -1,5 +1,5 @@
 'use strict'
-const bls = require('./bls.js')
+const bls = require('./index.js')
 const assert = require('assert')
 const fs = require('fs')
 const readline = require('readline')