[Refactor] use to-buffer

Author: ljharb

index.js

@@ -1,5 +1,6 @@
 'use strict'
 var Buffer = require('safe-buffer').Buffer
+var toBuffer = require('./to-buffer')
 var Transform = require('readable-stream').Transform
 var inherits = require('inherits')
 
@@ -38,55 +39,6 @@ HashBase.prototype._flush = function (callback) {
   callback(error)
 }
 
-var useUint8Array = typeof Uint8Array !== 'undefined'
-var useArrayBuffer = typeof ArrayBuffer !== 'undefined' &&
-  typeof Uint8Array !== 'undefined' &&
-  ArrayBuffer.isView &&
-  (Buffer.prototype instanceof Uint8Array || Buffer.TYPED_ARRAY_SUPPORT)
-
-function toBuffer (data, encoding) {
-  // No need to do anything for exact instance
-  // This is only valid when safe-buffer.Buffer === buffer.Buffer, i.e. when Buffer.from/Buffer.alloc existed
-  if (data instanceof Buffer) return data
-
-  // Convert strings to Buffer
-  if (typeof data === 'string') return Buffer.from(data, encoding)
-
-  /*
-   * Wrap any TypedArray instances and DataViews
-   * Makes sense only on engines with full TypedArray support -- let Buffer detect that
-   */
-  if (useArrayBuffer && ArrayBuffer.isView(data)) {
-    if (data.byteLength === 0) return Buffer.alloc(0) // Bug in Node.js <6.3.1, which treats this as out-of-bounds
-    var res = Buffer.from(data.buffer, data.byteOffset, data.byteLength)
-    // Recheck result size, as offset/length doesn't work on Node.js <5.10
-    // We just go to Uint8Array case if this fails
-    if (res.byteLength === data.byteLength) return res
-  }
-
-  /*
-   * Uint8Array in engines where Buffer.from might not work with ArrayBuffer, just copy over
-   * Doesn't make sense with other TypedArray instances
-   */
-  if (useUint8Array && data instanceof Uint8Array) return Buffer.from(data)
-
-  /*
-   * Old Buffer polyfill on an engine that doesn't have TypedArray support
-   * Also, this is from a different Buffer polyfill implementation then we have, as instanceof check failed
-   * Convert to our current Buffer implementation
-   */
-  if (
-    Buffer.isBuffer(data) &&
-    data.constructor &&
-    typeof data.constructor.isBuffer === 'function' &&
-    data.constructor.isBuffer(data)
-  ) {
-    return Buffer.from(data)
-  }
-
-  throw new TypeError('The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView.')
-}
-
 HashBase.prototype.update = function (data, encoding) {
   if (this._finalized) throw new Error('Digest already called')
 

package.json

@@ -30,7 +30,8 @@
 	"dependencies": {
 		"inherits": "^2.0.4",
 		"readable-stream": "^2.3.8",
-		"safe-buffer": "^5.2.1"
+		"safe-buffer": "^5.2.1",
+		"to-buffer": "^1.2.1"
 	},
 	"devDependencies": {
 		"nyc": "^10.3.2",

test/index.js

@@ -68,7 +68,7 @@ test('HashBase#update', function (t) {
     var base = new HashBase(64)
     t.throws(function () {
       base.update(null)
-    }, /^TypeError: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView.$/)
+    }, /^TypeError: The "data" argument must be a string, a Buffer, a Uint8Array, or a DataView$/)
     t.end()
   })
 

to-buffer.js

@@ -0,0 +1,20 @@
+'use strict'
+
+var Buffer = require('safe-buffer').Buffer
+var toBuffer = require('to-buffer')
+
+var useUint8Array = typeof Uint8Array !== 'undefined'
+var useArrayBuffer = useUint8Array && typeof ArrayBuffer !== 'undefined'
+var isView = useArrayBuffer && ArrayBuffer.isView
+
+module.exports = function (thing, encoding) {
+  if (
+    typeof thing === 'string' ||
+    Buffer.isBuffer(thing) ||
+    (useUint8Array && thing instanceof Uint8Array) ||
+    (isView && isView(thing))
+  ) {
+    return toBuffer(thing, encoding)
+  }
+  throw new TypeError('The "data" argument must be a string, a Buffer, a Uint8Array, or a DataView')
+}