fix: add support for browser modules to @solana/spl-token (#1337)

* fix: add support for browser modules

* chore: format and lint

* chore: fix flow

Author: jstarry

token/js/.eslintignore

@@ -1 +1,2 @@
 /lib
+/test/dist

token/js/.eslintrc.js

@@ -5,6 +5,7 @@ module.exports = {
     browser: true,
     es6: true,
     node: true,
+    mocha: true,
   },
   extends: [
     'eslint:recommended',

token/js/.mocharc.js

@@ -0,0 +1,6 @@
+'use strict';
+
+// Configure Node.js tests
+module.exports = {
+  require: ['@babel/register', 'esm'],
+};

token/js/babel.config.json

@@ -1,17 +1,9 @@
 {
   "presets": [
-    [
-      "@babel/preset-env",
-      {
-        "targets": {
-          "node": "10"
-        }
-      }
-    ],
-    "@babel/preset-flow"
+    ["@babel/preset-env"],
+    ["@babel/preset-flow"]
   ],
   "plugins": [
-    "@babel/plugin-transform-runtime",
     "@babel/plugin-proposal-class-properties"
   ]
 }

token/js/client/layout.js

@@ -1,7 +1,6 @@
 // @flow
 
 import * as BufferLayout from 'buffer-layout';
-import {Buffer} from 'buffer';
 
 /**
  * Layout for a public key
@@ -16,33 +15,3 @@ export const publicKey = (property: string = 'publicKey'): Object => {
 export const uint64 = (property: string = 'uint64'): Object => {
   return BufferLayout.blob(8, property);
 };
-
-/**
- * Layout for a Rust String type
- */
-export const rustString = (property: string = 'string'): Object => {
-  const rsl = BufferLayout.struct(
-    [
-      BufferLayout.u32('length'),
-      BufferLayout.u32('lengthPadding'),
-      BufferLayout.blob(BufferLayout.offset(BufferLayout.u32(), -8), 'chars'),
-    ],
-    property,
-  );
-  const _decode = rsl.decode.bind(rsl);
-  const _encode = rsl.encode.bind(rsl);
-
-  rsl.decode = (buffer, offset) => {
-    const data = _decode(buffer, offset);
-    return data.chars.toString('utf8');
-  };
-
-  rsl.encode = (str, buffer, offset) => {
-    const data = {
-      chars: Buffer.from(str, 'utf8'),
-    };
-    return _encode(data, buffer, offset);
-  };
-
-  return rsl;
-};

token/js/client/token.js

@@ -27,6 +27,15 @@ export const TOKEN_PROGRAM_ID: PublicKey = new PublicKey(
   'TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA',
 );
 
+/**
+ * Unfortunately, BufferLayout.encode uses an `instanceof` check for `Buffer`
+ * which fails when using `publicKey.toBuffer()` directly because the bundled `Buffer`
+ * class in `@solana/web3.js` is different from the bundled `Buffer` class in this package
+ */
+function pubkeyToBuffer(publicKey: PublicKey): typeof Buffer {
+  return Buffer.from(publicKey.toBuffer());
+}
+
 /**
  * 64-bit value
  */
@@ -1300,9 +1309,9 @@ export class Token {
         {
           instruction: 0, // InitializeMint instruction
           decimals,
-          mintAuthority: mintAuthority.toBuffer(),
+          mintAuthority: pubkeyToBuffer(mintAuthority),
           option: freezeAuthority === null ? 0 : 1,
-          freezeAuthority: (freezeAuthority || new PublicKey()).toBuffer(),
+          freezeAuthority: pubkeyToBuffer(freezeAuthority || new PublicKey()),
         },
         data,
       );
@@ -1544,7 +1553,7 @@ export class Token {
           instruction: 6, // SetAuthority instruction
           authorityType: AuthorityTypeCodes[authorityType],
           option: newAuthority === null ? 0 : 1,
-          newAuthority: (newAuthority || new PublicKey()).toBuffer(),
+          newAuthority: pubkeyToBuffer(newAuthority || new PublicKey()),
         },
         data,
       );