Added constructor ABIs to abi-gen

Additionally if the constructor is not existent in JSON, meaning it's
implcite with no parameters, we're
explicitly creating one, with actual JSON parameters that it should have.

2 files changed, 16 insertions, 0 deletions

diff --git a/packages/abi-gen/src/index.ts b/packages/abi-gen/src/index.ts
index ed71087b2..65dc1c607 100644
--- a/packages/abi-gen/src/index.ts
+++ b/packages/abi-gen/src/index.ts
@@ -14,6 +14,7 @@ import * as Web3 from 'web3';
 import { ContextData, ParamKind } from './types';
 import { utils } from './utils';
 
+const ABI_TYPE_CONSTRUCTOR = 'constructor';
 const ABI_TYPE_METHOD = 'function';
 const ABI_TYPE_EVENT = 'event';
 const MAIN_TEMPLATE_NAME = 'contract.mustache';
@@ -75,6 +76,11 @@ for (const abiFileName of abiFileNames) {
         process.exit(1);
     }
 
+    let constructor = ABI.find((abi: Web3.AbiDefinition) => abi.type === ABI_TYPE_CONSTRUCTOR) as Web3.ConstructorAbi;
+    if (!constructor) {
+        constructor = utils.getEmptyConstructor(); // The constructor exists, but it's implicit in JSON's ABI definition
+    }
+
     const methodAbis = ABI.filter((abi: Web3.AbiDefinition) => abi.type === ABI_TYPE_METHOD) as Web3.MethodAbi[];
     const methodsData = _.map(methodAbis, methodAbi => {
         _.map(methodAbi.inputs, input => {
@@ -95,6 +101,7 @@ for (const abiFileName of abiFileNames) {
 
     const contextData = {
         contractName: namedContent.name,
+        constructor,
         methods: methodsData,
         events: eventAbis,
     };
diff --git a/packages/abi-gen/src/utils.ts b/packages/abi-gen/src/utils.ts
index 764daa142..524c54a5e 100644
--- a/packages/abi-gen/src/utils.ts
+++ b/packages/abi-gen/src/utils.ts
@@ -1,6 +1,7 @@
 import * as fs from 'fs';
 import * as _ from 'lodash';
 import * as path from 'path';
+import * as Web3 from 'web3';
 
 import { ParamKind } from './types';
 
@@ -56,4 +57,12 @@ export const utils = {
             throw new Error(`Failed to read ${filename}: ${err}`);
         }
     },
+    getEmptyConstructor(): Web3.ConstructorAbi {
+        return {
+            type: 'constructor',
+            stateMutability: 'nonpayable',
+            payable: false,
+            inputs: [],
+        };
+    },
 };