From 778eb3b425b5ab5b23d28e75be92feccd0fc56bc Mon Sep 17 00:00:00 2001
From: Richard Moore <github@ricmoo.com>
Date: Fri, 27 Sep 2019 21:56:42 -0400
Subject: [PATCH] Added less-common, but useful, coding functions to Interface.

---
 packages/abi/src.ts/interface.ts | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/packages/abi/src.ts/interface.ts b/packages/abi/src.ts/interface.ts
index e232d5b896..33d40b8a14 100644
--- a/packages/abi/src.ts/interface.ts
+++ b/packages/abi/src.ts/interface.ts
@@ -192,6 +192,10 @@ export class Interface {
     }
 
 
+    _decodeParams(params: Array<ParamType>, data: BytesLike): Array<any> {
+        return this._abiCoder.decode(params, data)
+    }
+
     _encodeParams(params: Array<ParamType>, values: Array<any>): string {
         return this._abiCoder.encode(params, values)
     }
@@ -200,6 +204,20 @@ export class Interface {
         return this._encodeParams(this.deploy.inputs, values || [ ]);
     }
 
+    decodeFunctionData(functionFragment: FunctionFragment | string, data: BytesLike): Array<any> {
+        if (typeof(functionFragment) === "string") {
+            functionFragment = this.getFunction(functionFragment);
+        }
+
+        const bytes = arrayify(data);
+
+        if (hexlify(bytes.slice(0, 4)) !== this.getSighash(functionFragment)) {
+            logger.throwArgumentError(`data signature does not match function ${ functionFragment.name }.`, "data", hexlify(bytes));
+        }
+
+        return this._decodeParams(functionFragment.inputs, bytes.slice(4));
+    }
+
     encodeFunctionData(functionFragment: FunctionFragment | string, values?: Array<any>): string {
         if (typeof(functionFragment) === "string") {
             functionFragment = this.getFunction(functionFragment);
@@ -243,6 +261,14 @@ export class Interface {
         });
     }
 
+    encodeFunctionResult(functionFragment: FunctionFragment | string, values?: Array<any>): string {
+        if (typeof(functionFragment) === "string") {
+            functionFragment = this.getFunction(functionFragment);
+        }
+
+        return hexlify(this._abiCoder.encode(functionFragment.outputs, values || [ ]));
+    }
+
     encodeFilterTopics(eventFragment: EventFragment, values: Array<any>): Array<string | Array<string>> {
         if (typeof(eventFragment) === "string") {
             eventFragment = this.getEvent(eventFragment);