From 3e091a29384033f9fd1294d7367ad4d023caa2cc Mon Sep 17 00:00:00 2001
From: Richard Moore <github@ricmoo.com>
Date: Wed, 1 Aug 2018 17:24:11 -0400
Subject: [PATCH] Added Vyper-style gas ABI support.

---
 src.ts/contracts/contract.ts  |  4 ++++
 src.ts/contracts/interface.ts | 13 +++++++++++--
 src.ts/utils/abi-coder.ts     | 19 +++++++++++++++++--
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/src.ts/contracts/contract.ts b/src.ts/contracts/contract.ts
index 4f8265689..3cdc4f7d8 100644
--- a/src.ts/contracts/contract.ts
+++ b/src.ts/contracts/contract.ts
@@ -206,6 +206,10 @@ function runMethod(contract: Contract, functionName: string, estimateOnly: boole
                     return contract.provider.estimateGas(tx);
                 }
 
+                if (tx.gasLimit == null && method.gas != null) {
+                    tx.gasLimit = method.gas;
+                }
+
                 if (!contract.signer) {
                     errors.throwError('sending a transaction require a signer', errors.UNSUPPORTED_OPERATION, { operation: 'sendTransaction' })
                 }
diff --git a/src.ts/contracts/interface.ts b/src.ts/contracts/interface.ts
index d254fc2db..1bf1039f8 100644
--- a/src.ts/contracts/interface.ts
+++ b/src.ts/contracts/interface.ts
@@ -39,6 +39,7 @@ export interface FunctionDescription {
     readonly inputs: Array<ParamType>;
     readonly outputs: Array<ParamType>;
     readonly payable: boolean;
+    readonly gas: BigNumber;
     encode(params: Array<any>): string;
     decode(data: string): any;
 }
@@ -85,9 +86,13 @@ class Description {
         for (var key in info) {
             let value = info[key];
             if (value != null && typeof(value) === 'object') {
-                defineFrozen(this, key, info[key]);
+                if (BigNumber.isBigNumber(value)) {
+                    defineReadOnly(this, key, value);
+                } else {
+                    defineFrozen(this, key, value);
+                }
             } else {
-                defineReadOnly(this, key, info[key]);
+                defineReadOnly(this, key, value);
             }
         }
     }
@@ -131,6 +136,8 @@ class _FunctionDescription extends Description implements FunctionDescription {
     readonly outputs: Array<ParamType>;
     readonly payable: boolean;
 
+    readonly gas: BigNumber;
+
     encode(params: Array<any>): string {
         errors.checkArgumentCount(params.length, this.inputs.length, 'in interface function ' + this.name);
 
@@ -313,6 +320,8 @@ function addMethod(method: any): void {
                 inputs: method.inputs,
                 outputs: method.outputs,
 
+                gas: method.gas,
+
                 payable: (method.payable == null || !!method.payable),
                 type: ((method.constant) ? 'call': 'transaction'),
 
diff --git a/src.ts/utils/abi-coder.ts b/src.ts/utils/abi-coder.ts
index 6205b14e5..d8d47b09b 100644
--- a/src.ts/utils/abi-coder.ts
+++ b/src.ts/utils/abi-coder.ts
@@ -3,7 +3,7 @@
 // See: https://github.com/ethereum/wiki/wiki/Ethereum-Contract-ABI
 
 import { getAddress } from  './address';
-import { bigNumberify, ConstantNegativeOne, ConstantZero, ConstantOne, ConstantMaxUint256 } from './bignumber';
+import { BigNumber, bigNumberify, ConstantNegativeOne, ConstantZero, ConstantOne, ConstantMaxUint256 } from './bignumber';
 import { arrayify, concat, hexlify, padZeros } from './bytes';
 import { toUtf8Bytes, toUtf8String } from './utf8';
 import { defineReadOnly, jsonCopy } from './properties';
@@ -50,6 +50,8 @@ export type FunctionFragment = {
 
     payable: boolean,
     stateMutability: string,
+
+    gas: BigNumber
 };
 
 ///////////////////////////////
@@ -272,6 +274,7 @@ function parseSignatureEvent(fragment: string): EventFragment {
 function parseSignatureFunction(fragment: string): FunctionFragment {
     var abi: FunctionFragment = {
         constant: false,
+        gas: null,
         inputs: [],
         name: '',
         outputs: [],
@@ -280,7 +283,19 @@ function parseSignatureFunction(fragment: string): FunctionFragment {
         type: 'function'
     };
 
-    var comps = fragment.split(' returns ');
+    let comps = fragment.split('@');
+    if (comps.length !== 1) {
+        if (comps.length > 2) {
+            throw new Error('invalid signature');
+        }
+        if (!comps[1].match(/^[0-9]+$/)) {
+            throw new Error('invalid signature gas');
+        }
+        abi.gas = bigNumberify(comps[1]);
+        fragment = comps[0];
+    }
+
+    comps = fragment.split(' returns ');
     var left = comps[0].match(regexParen);
     if (!left) { throw new Error('invalid signature'); }