Enforce buffer inputs for setLengthLeft/Right

cgewecke · cgewecke · commit 686f8daf9b18 · 2020-04-23T23:43:35.000-07:00
diff --git a/docs/modules/_bytes_.md b/docs/modules/_bytes_.md
@@ -135,46 +135,46 @@ ___
 
 ### `Const` setLengthLeft
 
-▸ **setLengthLeft**(`msg`: any, `length`: number, `right`: boolean): *any*
+▸ **setLengthLeft**(`msg`: Buffer, `length`: number, `right`: boolean): *any*
 
 *Defined in [bytes.ts:20](https://github.com/ethereumjs/ethereumjs-util/blob/master/src/bytes.ts#L20)*
 
-Left Pads an `Array` or `Buffer` with leading zeros till it has `length` bytes.
+Left Pads a `Buffer` with leading zeros till it has `length` bytes.
 Or it truncates the beginning if it exceeds.
 
 **Parameters:**
 
 Name | Type | Default | Description |
 ------ | ------ | ------ | ------ |
-`msg` | any | - | the value to pad (Buffer|Array) |
+`msg` | Buffer | - | the value to pad (Buffer) |
 `length` | number | - | the number of bytes the output should be |
 `right` | boolean | false | whether to start padding form the left or right |
 
 **Returns:** *any*
 
-(Buffer|Array)
+(Buffer)
 
 ___
 
 ### `Const` setLengthRight
 
-▸ **setLengthRight**(`msg`: any, `length`: number): *any*
+▸ **setLengthRight**(`msg`: Buffer, `length`: number): *any*
 
 *Defined in [bytes.ts:46](https://github.com/ethereumjs/ethereumjs-util/blob/master/src/bytes.ts#L46)*
 
-Right Pads an `Array` or `Buffer` with leading zeros till it has `length` bytes.
+Right Pads a `Buffer` with leading zeros till it has `length` bytes.
 Or it truncates the beginning if it exceeds.
 
 **Parameters:**
 
 Name | Type | Description |
 ------ | ------ | ------ |
-`msg` | any | the value to pad (Buffer|Array) |
+`msg` | Buffer | the value to pad (Buffer) |
 `length` | number | the number of bytes the output should be |
 
 **Returns:** *any*
 
-(Buffer|Array)
+(Buffer)
 
 ___
 
diff --git a/src/bytes.ts b/src/bytes.ts
@@ -1,5 +1,6 @@
 const ethjsUtil = require('ethjs-util')
 import * as BN from 'bn.js'
+import { assertIsBuffer } from './helpers'
 
 /**
  * Returns a buffer filled with 0s.
@@ -10,16 +11,16 @@ export const zeros = function(bytes: number): Buffer {
 }
 
 /**
- * Left Pads an `Array` or `Buffer` with leading zeros till it has `length` bytes.
+ * Left Pads a `Buffer` with leading zeros till it has `length` bytes.
  * Or it truncates the beginning if it exceeds.
- * @param msg the value to pad (Buffer|Array)
+ * @param msg the value to pad (Buffer)
  * @param length the number of bytes the output should be
  * @param right whether to start padding form the left or right
- * @return (Buffer|Array)
+ * @return (Buffer)
  */
-export const setLengthLeft = function(msg: any, length: number, right: boolean = false) {
+export const setLengthLeft = function(msg: Buffer, length: number, right: boolean = false) {
+  assertIsBuffer(msg)
   const buf = zeros(length)
-  msg = toBuffer(msg)
   if (right) {
     if (msg.length < length) {
       msg.copy(buf)
@@ -37,14 +38,14 @@ export const setLengthLeft = function(msg: any, length: number, right: boolean =
 export const setLength = setLengthLeft
 
 /**
- * Right Pads an `Array` or `Buffer` with leading zeros till it has `length` bytes.
+ * Right Pads a `Buffer` with leading zeros till it has `length` bytes.
  * Or it truncates the beginning if it exceeds.
- * @param msg the value to pad (Buffer|Array)
+ * @param msg the value to pad (Buffer)
  * @param length the number of bytes the output should be
- * @return (Buffer|Array)
+ * @return (Buffer)
  */
-export const setLengthRight = function(msg: any, length: number) {
-  return setLength(msg, length, true)
+export const setLengthRight = function(msg: Buffer, length: number) {
+  return setLengthLeft(msg, length, true)
 }
 
 /**
@@ -61,6 +62,7 @@ export const unpad = function(a: any) {
   }
   return a
 }
+
 export const stripZeros = unpad
 
 /**
diff --git a/test/bytes.spec.ts b/test/bytes.spec.ts
@@ -5,7 +5,6 @@ import {
   zeroAddress,
   isZeroAddress,
   unpad,
-  setLength,
   setLengthLeft,
   setLengthRight,
   bufferToHex,
@@ -64,39 +63,39 @@ describe('unpad a hex string', function() {
   })
 })
 
-describe('pad', function() {
+describe('setLengthLeft', function() {
   it('should left pad a Buffer', function() {
     const buf = Buffer.from([9, 9])
-    const padded = setLength(buf, 3)
+    const padded = setLengthLeft(buf, 3)
     assert.equal(padded.toString('hex'), '000909')
   })
   it('should left truncate a Buffer', function() {
     const buf = Buffer.from([9, 0, 9])
-    const padded = setLength(buf, 2)
+    const padded = setLengthLeft(buf, 2)
     assert.equal(padded.toString('hex'), '0009')
   })
-  it('should left pad a Buffer - alias', function() {
-    const buf = Buffer.from([9, 9])
-    const padded = setLengthLeft(buf, 3)
-    assert.equal(padded.toString('hex'), '000909')
+  it('should throw if input is not a Buffer', function() {
+    assert.throws(function() {
+      setLengthLeft((<unknown>[9, 9]) as Buffer, 3)
+    })
   })
 })
 
-describe('rpad', function() {
+describe('setLengthRight', function() {
   it('should right pad a Buffer', function() {
     const buf = Buffer.from([9, 9])
-    const padded = setLength(buf, 3, true)
+    const padded = setLengthRight(buf, 3)
     assert.equal(padded.toString('hex'), '090900')
   })
   it('should right truncate a Buffer', function() {
     const buf = Buffer.from([9, 0, 9])
-    const padded = setLength(buf, 2, true)
+    const padded = setLengthRight(buf, 2)
     assert.equal(padded.toString('hex'), '0900')
   })
-  it('should right pad a Buffer - alias', function() {
-    const buf = Buffer.from([9, 9])
-    const padded = setLengthRight(buf, 3)
-    assert.equal(padded.toString('hex'), '090900')
+  it('should throw if input is not a Buffer', function() {
+    assert.throws(function() {
+      setLengthRight((<unknown>[9, 9]) as Buffer, 3)
+    })
   })
 })
 
