prepare beta4

Author: alexvictoor

README.md

@@ -27,7 +27,7 @@ This library is packaged as a UMD module, hence you can use it directly
 from JavaScript within a browser. To do so, you can simply include HdrHistogramJS file from github's release page:
 
 ```
-<script src="https://github.com/HdrHistogram/HdrHistogramJS/releases/download/v2.0.0/hdrhistogram.min.js"></script>
+<script src="https://github.com/HdrHistogram/HdrHistogramJS/releases/download/v2.0.0-beta4/hdrhistogram.umd.js"></script>
 ```
 
 Then you will have access to classes and functions of the APIs using "hdr" prefix.

src/JsHistogram.encoding.ts

@@ -141,19 +141,19 @@ function findDeflateFunction() {
   try {
     return eval('require("zlib").deflateSync');
   } catch (error) {
-    return pako.deflate;
+    return !!pako ? pako.deflate : () => { throw new Error('pako library is mandatory for encoding/deconding on the browser side') };
   }
 }
 function findInflateFunction() {
   try {
     return eval('require("zlib").inflateSync');
   } catch (error) {
-    return pako.inflate;
+    return !!pako ? pako.inflate : () => { throw new Error('pako library is mandatory for encoding/deconding on the browser side') };
   }
 }
 
-const deflate = findDeflateFunction();
-const inflate = findInflateFunction();
+export const deflate = findDeflateFunction();
+export const inflate = findInflateFunction();
 
 export function decompress(data: Uint8Array): Uint8Array {
   const buffer = new ByteBuffer(data);

src/encoding.ts

@@ -5,38 +5,18 @@
  * and released to the public domain, as explained at
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
-import "./JsHistogram.encoding";
 import { JsHistogram } from "./JsHistogram";
 import ByteBuffer from "./ByteBuffer";
 import Histogram from "./Histogram";
 import { WasmHistogram } from "./wasm";
 
 // @ts-ignore
 import * as base64 from "base64-js";
-// @ts-ignore
-import * as pako from "pako";
+import { inflate, deflate } from "./JsHistogram.encoding";
 
 const V2CompressedEncodingCookieBase = 0x1c849304;
 const compressedEncodingCookie = V2CompressedEncodingCookieBase | 0x10; // LSBit of wordsize byte indicates TLZE Encoding
 
-function findDeflateFunction() {
-  try {
-    return eval('require("zlib").deflateSync');
-  } catch (error) {
-    return pako.deflate;
-  }
-}
-function findInflateFunction() {
-  try {
-    return eval('require("zlib").inflateSync');
-  } catch (error) {
-    return pako.inflate;
-  }
-}
-
-const deflate = findDeflateFunction();
-const inflate = findInflateFunction();
-
 export function decompress(data: Uint8Array): Uint8Array {
   const buffer = new ByteBuffer(data);
   const initialTargetPosition = buffer.position;