Tests for decoding return values + Ability to encode return values

2 files changed, 79 insertions, 9 deletions

diff --git a/packages/utils/src/abi_encoder/evm_data_types.ts b/packages/utils/src/abi_encoder/evm_data_types.ts
index 10e7b987b..b862e9396 100644
--- a/packages/utils/src/abi_encoder/evm_data_types.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types.ts
@@ -276,7 +276,7 @@ export class Byte extends PayloadDataType {
         if (valueBuf.byteLength > this.width) {
             throw new Error(
                 `Tried to assign ${value} (${
-                    valueBuf.byteLength
+                valueBuf.byteLength
                 } bytes), which exceeds max bytes that can be stored in a ${this.getSignature()}`,
             );
         } else if (value.length % 2 !== 0) {
@@ -475,6 +475,7 @@ export class Method extends MemberDataType {
     private methodSignature: string;
     private methodSelector: string;
     private returnDataTypes: DataType[];
+    private returnDataItem: DataItem;
 
     // TMP
     public selector: string;
@@ -484,6 +485,7 @@ export class Method extends MemberDataType {
         this.methodSignature = this.computeSignature();
         this.selector = this.methodSelector = this.computeSelector();
         this.returnDataTypes = [];
+        this.returnDataItem = { type: 'tuple', name: abi.name, components: abi.outputs };
         const dummy = new Byte({ type: 'byte', name: 'DUMMY' }); // @TODO TMP
         _.each(abi.outputs, (dataItem: DataItem) => {
             this.returnDataTypes.push(this.getFactory().create(dataItem, dummy));
@@ -518,20 +520,19 @@ export class Method extends MemberDataType {
         return value;
     }
 
-    public decodeReturnValues(returndata: string, rules?: DecodingRules): any {
-        //console.log('O'.repeat(100), '\n', returndata, '\n', this.returnDataTypes, 'P'.repeat(100));
+    public encodeReturnValues(value: any, rules?: EncodingRules): string {
+        const returnDataType = new Tuple(this.returnDataItem);
+        const returndata = returnDataType.encode(value, rules);
+        return returndata;
+    }
 
+    public decodeReturnValues(returndata: string, rules?: DecodingRules): any {
         const returnValues: any[] = [];
         const rules_ = rules ? rules : ({ structsAsObjects: false } as DecodingRules);
         const rawReturnData = new RawCalldata(returndata, false);
         _.each(this.returnDataTypes, (dataType: DataType) => {
             returnValues.push(dataType.generateValue(rawReturnData, rules_));
         });
-
-        //console.log('*'.repeat(40), '\n', JSON.stringify(returnValues), '\n', '*'.repeat(100));
-        /*if (returnValues.length === 1) {
-            return returnValues[0];
-        }*/
         return returnValues;
     }
 
@@ -547,7 +548,7 @@ export class Method extends MemberDataType {
 export class EvmDataTypeFactory implements DataTypeFactory {
     private static instance: DataTypeFactory;
 
-    private constructor() {}
+    private constructor() { }
 
     public static getInstance(): DataTypeFactory {
         if (!EvmDataTypeFactory.instance) {
diff --git a/packages/utils/test/abi_encoder_test.ts b/packages/utils/test/abi_encoder_test.ts
index b672d0023..0220984b0 100644
--- a/packages/utils/test/abi_encoder_test.ts
+++ b/packages/utils/test/abi_encoder_test.ts
@@ -5,6 +5,7 @@ import { chaiSetup } from './utils/chai_setup';
 import { BigNumber, AbiEncoder } from '../src/';
 import * as AbiSamples from './abi_samples';
 import * as OptimizedAbis from './optimizer_abis';
+import * as ReturnValueAbis from './return_value_abis';
 import { DecodingRules } from '../src/abi_encoder';
 import ethUtil = require('ethereumjs-util');
 
@@ -12,6 +13,74 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe.only('ABI Encoder', () => {
+    describe('Decode Return Values', () => {
+        it('No Return Value', async () => {
+            // Decode return value
+            const method = new AbiEncoder.Method(ReturnValueAbis.noReturnValues);
+            const returnValue = '0x';
+            const decodedReturnValue = method.decodeReturnValues(returnValue);
+            const expectedDecodedReturnValue: any[] = [];
+            const decodedReturnValueJson = JSON.stringify(decodedReturnValue);
+            const expectedDecodedReturnValueJson = JSON.stringify(expectedDecodedReturnValue);
+            expect(decodedReturnValueJson).to.be.equal(expectedDecodedReturnValueJson);
+        });
+        it('Single static return value', async () => {
+            // Generate Return Value
+            const method = new AbiEncoder.Method(ReturnValueAbis.singleStaticReturnValue);
+            const returnValue = ['0x01020304'];
+            const encodedReturnValue = method.encodeReturnValues(returnValue);
+            const decodedReturnValue = method.decodeReturnValues(encodedReturnValue);
+            // Validate decoded return value
+            const decodedReturnValueJson = JSON.stringify(decodedReturnValue);
+            const expectedDecodedReturnValueJson = JSON.stringify(returnValue);
+            expect(decodedReturnValueJson).to.be.equal(expectedDecodedReturnValueJson);
+        });
+        it('Multiple static return values', async () => {
+            // Generate Return Value
+            const method = new AbiEncoder.Method(ReturnValueAbis.multipleStaticReturnValues);
+            const returnValue = ['0x01020304', '0x05060708'];
+            const encodedReturnValue = method.encodeReturnValues(returnValue);
+            const decodedReturnValue = method.decodeReturnValues(encodedReturnValue);
+            // Validate decoded return value
+            const decodedReturnValueJson = JSON.stringify(decodedReturnValue);
+            const expectedDecodedReturnValueJson = JSON.stringify(returnValue);
+            expect(decodedReturnValueJson).to.be.equal(expectedDecodedReturnValueJson);
+        });
+        it('Single dynamic return value', async () => {
+            // Generate Return Value
+            const method = new AbiEncoder.Method(ReturnValueAbis.singleDynamicReturnValue);
+            const returnValue = ['0x01020304'];
+            const encodedReturnValue = method.encodeReturnValues(returnValue);
+            const decodedReturnValue = method.decodeReturnValues(encodedReturnValue);
+            // Validate decoded return value
+            const decodedReturnValueJson = JSON.stringify(decodedReturnValue);
+            const expectedDecodedReturnValueJson = JSON.stringify(returnValue);
+            expect(decodedReturnValueJson).to.be.equal(expectedDecodedReturnValueJson);
+        });
+        it('Multiple dynamic return values', async () => {
+            // Generate Return Value
+            const method = new AbiEncoder.Method(ReturnValueAbis.multipleDynamicReturnValues);
+            const returnValue = ['0x01020304', '0x05060708'];
+            const encodedReturnValue = method.encodeReturnValues(returnValue);
+            const decodedReturnValue = method.decodeReturnValues(encodedReturnValue);
+            // Validate decoded return value
+            const decodedReturnValueJson = JSON.stringify(decodedReturnValue);
+            const expectedDecodedReturnValueJson = JSON.stringify(returnValue);
+            expect(decodedReturnValueJson).to.be.equal(expectedDecodedReturnValueJson);
+        });
+        it('Mixed static/dynamic return values', async () => {
+            // Generate Return Value
+            const method = new AbiEncoder.Method(ReturnValueAbis.mixedStaticAndDynamicReturnValues);
+            const returnValue = ['0x01020304', '0x05060708'];
+            const encodedReturnValue = method.encodeReturnValues(returnValue);
+            const decodedReturnValue = method.decodeReturnValues(encodedReturnValue);
+            // Validate decoded return value
+            const decodedReturnValueJson = JSON.stringify(decodedReturnValue);
+            const expectedDecodedReturnValueJson = JSON.stringify(returnValue);
+            expect(decodedReturnValueJson).to.be.equal(expectedDecodedReturnValueJson);
+        });
+    });
+
     describe('Optimizer', () => {
         it('Duplicate Dynamic Arrays with Static Elements', async () => {
             // Generate calldata