removed NodeJS dependency from common.js

contract.js

@@ -1,8 +1,32 @@
-import {AbiFileCache} from "../web/src/common.js"
+import {AsyncAbiCache} from "../web/src/common.js"
 import {ethers} from "ethers";
+import fs from "fs";
 
 const ABI_BASE_URL = '../contract/out/'
 
+
+export class AsyncFileCache extends AsyncAbiCache {
+    constructor(pathForKey) {
+        super(async (key) => {
+            const path = this.pathForKey(key)
+            const data = fs.readFileSync(path, 'utf8');
+            return JSON.parse(data);
+        })
+        this.pathForKey = pathForKey
+    }
+}
+
+
+export class AbiFileCache extends AsyncFileCache {
+    constructor(basePath) {
+        super((name)=>{
+            return this.basePath+abiPath(name)
+        })
+        this.basePath = basePath.endsWith('/') ? basePath : basePath + '/'
+    }
+}
+
+
 const abiCache = new AbiFileCache(ABI_BASE_URL)