From 5e4535e939fdb9d9d23bd14b3e2590873d3eb508 Mon Sep 17 00:00:00 2001
From: Richard Moore <github@ricmoo.com>
Date: Tue, 11 Jun 2019 23:42:35 -0400
Subject: [PATCH] Added getStatic with support for inheritance of static
 methods.

---
 packages/abi/src.ts/interface.ts    |  4 ++--
 packages/contracts/src.ts/index.ts  | 10 ++++++----
 packages/properties/src.ts/index.ts | 10 ++++++++++
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/packages/abi/src.ts/interface.ts b/packages/abi/src.ts/interface.ts
index d4a5c72bd8..05f79c7215 100644
--- a/packages/abi/src.ts/interface.ts
+++ b/packages/abi/src.ts/interface.ts
@@ -6,7 +6,7 @@ import { arrayify, BytesLike, concat, hexDataSlice, hexlify, hexZeroPad, isHexSt
 import { id } from "@ethersproject/hash";
 import { keccak256 } from "@ethersproject/keccak256"
 import * as errors from "@ethersproject/errors";
-import { defineReadOnly, Description } from "@ethersproject/properties";
+import { defineReadOnly, Description, getStatic } from "@ethersproject/properties";
 
 import { AbiCoder, defaultAbiCoder } from "./abi-coder";
 import { ConstructorFragment, EventFragment, Fragment, FunctionFragment, JsonFragment, ParamType } from "./fragments";
@@ -71,7 +71,7 @@ export class Interface {
             return Fragment.from(fragment);
         }).filter((fragment) => (fragment != null)));
 
-        defineReadOnly(this, "_abiCoder", new.target.getAbiCoder());
+        defineReadOnly(this, "_abiCoder", getStatic<() => AbiCoder>(new.target, "getAbiCoder")());
 
         defineReadOnly(this, "functions", { });
         defineReadOnly(this, "errors", { });
diff --git a/packages/contracts/src.ts/index.ts b/packages/contracts/src.ts/index.ts
index a7b40b5575..3b8eb43618 100644
--- a/packages/contracts/src.ts/index.ts
+++ b/packages/contracts/src.ts/index.ts
@@ -8,7 +8,7 @@ import { BigNumber, BigNumberish } from "@ethersproject/bignumber";
 import { BytesLike, concat, hexlify, isBytes, isHexString } from "@ethersproject/bytes";
 import { Zero } from "@ethersproject/constants";
 import * as errors from "@ethersproject/errors";
-import { defineReadOnly, deepCopy, resolveProperties, shallowCopy } from "@ethersproject/properties";
+import { defineReadOnly, deepCopy, getStatic, resolveProperties, shallowCopy } from "@ethersproject/properties";
 import { UnsignedTransaction } from "@ethersproject/transactions";
 
 
@@ -402,6 +402,8 @@ class WildcardRunningEvent extends RunningEvent {
 
 export type ContractInterface = string | Array<Fragment | JsonFragment | string> | Interface;
 
+type InterfaceFunc = (contractInterface: ContractInterface) => Interface;
+
 export class Contract {
     readonly address: string;
     readonly interface: Interface;
@@ -437,8 +439,8 @@ export class Contract {
 
         // @TODO: Maybe still check the addressOrName looks like a valid address or name?
         //address = getAddress(address);
-
-        defineReadOnly(this, "interface", new.target.getInterface(contractInterface));
+console.log(getStatic(new.target, "getInterface"));
+        defineReadOnly(this, "interface", getStatic<InterfaceFunc>(new.target, "getInterface")(contractInterface));
 
         if (Signer.isSigner(signerOrProvider)) {
             defineReadOnly(this, "provider", signerOrProvider.provider || null);
@@ -850,7 +852,7 @@ export class ContractFactory {
         }
 
         defineReadOnly(this, "bytecode", bytecodeHex);
-        defineReadOnly(this, "interface", new.target.getInterface(contractInterface));
+        defineReadOnly(this, "interface", getStatic<InterfaceFunc>(new.target, "getInterface")(contractInterface));
         defineReadOnly(this, "signer", signer || null);
     }
 
diff --git a/packages/properties/src.ts/index.ts b/packages/properties/src.ts/index.ts
index 3f618a20d5..8466964d00 100644
--- a/packages/properties/src.ts/index.ts
+++ b/packages/properties/src.ts/index.ts
@@ -10,6 +10,16 @@ export function defineReadOnly(object: any, name: string, value: any): void {
     });
 }
 
+// Crawl up the constructor chain to find a static method
+export function getStatic<T>(ctor: any, key: string): T {
+    for (let i = 0; i < 32; i++) {
+        if (ctor[key]) { return ctor[key]; }
+        if (!ctor.prototype || typeof(ctor.prototype) !== "object") { break; }
+        ctor = Object.getPrototypeOf(ctor.prototype).constructor;
+    }
+    return null;
+}
+
 export function resolveProperties(object: any): Promise<any> {
     let result: any = {};