0xProject · fabioberger · Feb 6, 2019 · Feb 6, 2019 · Feb 6, 2019 · Feb 6, 2019
diff --git a/packages/utils/CHANGELOG.json b/packages/utils/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "version": "4.0.2",
+        "changes": [
+            {
+                "note": "ABI Decode NULL for all data types",
+                "pr": 1587
+            }
+        ]
+    },
     {
         "version": "4.0.1",
         "changes": [

diff --git a/packages/utils/src/abi_encoder/abstract_data_types/data_type.ts b/packages/utils/src/abi_encoder/abstract_data_types/data_type.ts
@@ -47,7 +47,8 @@ export abstract class DataType {
         const hasSelector = !_.isUndefined(selector);
         const rawCalldata = new RawCalldata(calldata, hasSelector);
         const rules_ = _.isUndefined(rules) ? constants.DEFAULT_DECODING_RULES : rules;
-        const value = this.generateValue(rawCalldata, rules_);
+        const value =
+            rawCalldata.getSizeInBytes() > 0 ? this.generateValue(rawCalldata, rules_) : this.getDefaultValue(rules_);
         return value;
     }
 
@@ -71,6 +72,7 @@ export abstract class DataType {
 
     public abstract generateCalldataBlock(value: any, parentBlock?: CalldataBlock): CalldataBlock;
     public abstract generateValue(calldata: RawCalldata, rules: DecodingRules): any;
+    public abstract getDefaultValue(rules?: DecodingRules): any;
     public abstract getSignatureType(): string;
     public abstract isStatic(): boolean;
 }
diff --git a/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts b/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts
@@ -97,6 +97,27 @@ export abstract class AbstractSetDataType extends DataType {
         return isStatic;
     }
 
+    public getDefaultValue(rules?: DecodingRules): any[] | object {
+        let defaultValue: any[] | object;
+        if (this._isArray && _.isUndefined(this._arrayLength)) {
+            defaultValue = [];
+        } else if (!_.isUndefined(rules) && rules.shouldConvertStructsToObjects && !this._isArray) {
+            defaultValue = {};
+            _.each(this._memberIndexByName, (idx: number, key: string) => {
+                const member = this._members[idx];
+                const memberValue = member.getDefaultValue();
+                (defaultValue as { [key: string]: any })[key] = memberValue;
+            });
+        } else {
+            defaultValue = [];
+            _.each(this._members, (member: DataType, idx: number) => {
+                const memberValue = member.getDefaultValue();
+                (defaultValue as any[]).push(memberValue);
+            });
+        }
+        return defaultValue;
+    }
+
     protected _generateCalldataBlockFromArray(value: any[], parentBlock?: CalldataBlock): SetCalldataBlock {
         // Sanity check: if the set has a defined length then `value` must have the same length.
         if (!_.isUndefined(this._arrayLength) && value.length !== this._arrayLength) {

diff --git a/packages/utils/src/abi_encoder/calldata/raw_calldata.ts b/packages/utils/src/abi_encoder/calldata/raw_calldata.ts
@@ -79,4 +79,9 @@ export class RawCalldata {
     public getSelector(): string {
         return this._selector;
     }
+
+    public getSizeInBytes(): number {
+        const sizeInBytes = this._value.byteLength;
+        return sizeInBytes;
+    }
 }
diff --git a/packages/utils/src/abi_encoder/evm_data_types/address.ts b/packages/utils/src/abi_encoder/evm_data_types/address.ts
@@ -12,6 +12,7 @@ export class AddressDataType extends AbstractBlobDataType {
     private static readonly _ADDRESS_SIZE_IN_BYTES = 20;
     private static readonly _DECODED_ADDRESS_OFFSET_IN_BYTES =
         constants.EVM_WORD_WIDTH_IN_BYTES - AddressDataType._ADDRESS_SIZE_IN_BYTES;
+    private static readonly _DEFAULT_VALUE = '0x0000000000000000000000000000000000000000';
 
     public static matchType(type: string): boolean {
         return type === SolidityTypes.Address;
@@ -43,6 +44,10 @@ export class AddressDataType extends AbstractBlobDataType {
         return valueLowercase;
     }
 
+    public getDefaultValue(): string {
+        return AddressDataType._DEFAULT_VALUE;
+    }
+
     public getSignatureType(): string {
         return SolidityTypes.Address;
     }

diff --git a/packages/utils/src/abi_encoder/evm_data_types/bool.ts b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
@@ -10,6 +10,7 @@ import { constants } from '../utils/constants';
 
 export class BoolDataType extends AbstractBlobDataType {
     private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+    private static readonly _DEFAULT_VALUE: boolean = false;
 
     public static matchType(type: string): boolean {
         return type === SolidityTypes.Bool;
@@ -47,6 +48,10 @@ export class BoolDataType extends AbstractBlobDataType {
         return value;
     }
 
+    public getDefaultValue(): boolean {
+        return BoolDataType._DEFAULT_VALUE;
+    }
+
     public getSignatureType(): string {
         return SolidityTypes.Bool;
     }

diff --git a/packages/utils/src/abi_encoder/evm_data_types/dynamic_bytes.ts b/packages/utils/src/abi_encoder/evm_data_types/dynamic_bytes.ts
@@ -9,6 +9,7 @@ import { constants } from '../utils/constants';
 
 export class DynamicBytesDataType extends AbstractBlobDataType {
     private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = false;
+    private static readonly _DEFAULT_VALUE = '0x';
 
     public static matchType(type: string): boolean {
         return type === SolidityTypes.Bytes;
@@ -65,6 +66,10 @@ export class DynamicBytesDataType extends AbstractBlobDataType {
         return value;
     }
 
+    public getDefaultValue(): string {
+        return DynamicBytesDataType._DEFAULT_VALUE;
+    }
+
     public getSignatureType(): string {
         return SolidityTypes.Bytes;
     }

diff --git a/packages/utils/src/abi_encoder/evm_data_types/int.ts b/packages/utils/src/abi_encoder/evm_data_types/int.ts
@@ -15,6 +15,7 @@ export class IntDataType extends AbstractBlobDataType {
     private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
     private static readonly _MAX_WIDTH: number = 256;
     private static readonly _DEFAULT_WIDTH: number = IntDataType._MAX_WIDTH;
+    private static readonly _DEFAULT_VALUE = new BigNumber(0);
     private readonly _width: number;
     private readonly _minValue: BigNumber;
     private readonly _maxValue: BigNumber;
@@ -50,13 +51,20 @@ export class IntDataType extends AbstractBlobDataType {
     public decodeValue(calldata: RawCalldata): BigNumber | number {
         const valueBuf = calldata.popWord();
         const value = EncoderMath.safeDecodeNumericValue(valueBuf, this._minValue, this._maxValue);
-        const numberOfBytesInUint8 = 8;
-        if (this._width === numberOfBytesInUint8) {
+        if (this._width === constants.NUMBER_OF_BYTES_IN_INT8) {
             return value.toNumber();
         }
         return value;
     }
 
+    public getDefaultValue(): BigNumber | number {
+        const defaultValue = IntDataType._DEFAULT_VALUE;
+        if (this._width === constants.NUMBER_OF_BYTES_IN_INT8) {
+            return defaultValue.toNumber();
+        }
+        return defaultValue;
+    }
+
     public getSignatureType(): string {
         return `${SolidityTypes.Int}${this._width}`;
     }

diff --git a/packages/utils/src/abi_encoder/evm_data_types/pointer.ts b/packages/utils/src/abi_encoder/evm_data_types/pointer.ts
@@ -18,4 +18,9 @@ export class PointerDataType extends AbstractPointerDataType {
     public getSignature(isDetailed?: boolean): string {
         return this._destination.getSignature(isDetailed);
     }
+
+    public getDefaultValue(): any {
+        const defaultValue = this._destination.getDefaultValue();
+        return defaultValue;
+    }
 }
diff --git a/packages/utils/src/abi_encoder/evm_data_types/static_bytes.ts b/packages/utils/src/abi_encoder/evm_data_types/static_bytes.ts
@@ -58,6 +58,13 @@ export class StaticBytesDataType extends AbstractBlobDataType {
         return value;
     }
 
+    public getDefaultValue(): string {
+        const valueBufPadded = constants.EMPTY_EVM_WORD_BUFFER;
+        const valueBuf = valueBufPadded.slice(0, this._width);
+        const value = ethUtil.bufferToHex(valueBuf);
+        return value;
+    }
+
     private _sanityCheckValue(value: string | Buffer): void {
         if (typeof value === 'string') {
             if (!_.startsWith(value, '0x')) {

diff --git a/packages/utils/src/abi_encoder/evm_data_types/string.ts b/packages/utils/src/abi_encoder/evm_data_types/string.ts
@@ -9,6 +9,7 @@ import { constants } from '../utils/constants';
 
 export class StringDataType extends AbstractBlobDataType {
     private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = false;
+    private static readonly _DEFAULT_VALUE = '';
 
     public static matchType(type: string): boolean {
         return type === SolidityTypes.String;
@@ -52,6 +53,10 @@ export class StringDataType extends AbstractBlobDataType {
         return value;
     }
 
+    public getDefaultValue(): string {
+        return StringDataType._DEFAULT_VALUE;
+    }
+
     public getSignatureType(): string {
         return SolidityTypes.String;
     }

diff --git a/packages/utils/src/abi_encoder/evm_data_types/uint.ts b/packages/utils/src/abi_encoder/evm_data_types/uint.ts
@@ -16,6 +16,7 @@ export class UIntDataType extends AbstractBlobDataType {
     private static readonly _MAX_WIDTH: number = 256;
     private static readonly _DEFAULT_WIDTH: number = UIntDataType._MAX_WIDTH;
     private static readonly _MIN_VALUE = new BigNumber(0);
+    private static readonly _DEFAULT_VALUE = new BigNumber(0);
     private readonly _width: number;
     private readonly _maxValue: BigNumber;
 
@@ -49,13 +50,20 @@ export class UIntDataType extends AbstractBlobDataType {
     public decodeValue(calldata: RawCalldata): BigNumber | number {
         const valueBuf = calldata.popWord();
         const value = EncoderMath.safeDecodeNumericValue(valueBuf, UIntDataType._MIN_VALUE, this._maxValue);
-        const numberOfBytesInUint8 = 8;
-        if (this._width === numberOfBytesInUint8) {
+        if (this._width === constants.NUMBER_OF_BYTES_IN_UINT8) {
             return value.toNumber();
         }
         return value;
     }
 
+    public getDefaultValue(): BigNumber | number {
+        const defaultValue = UIntDataType._DEFAULT_VALUE;
+        if (this._width === constants.NUMBER_OF_BYTES_IN_UINT8) {
+            return defaultValue.toNumber();
+        }
+        return defaultValue;
+    }
+
     public getSignatureType(): string {
         return `${SolidityTypes.Uint}${this._width}`;
     }

diff --git a/packages/utils/src/abi_encoder/utils/constants.ts b/packages/utils/src/abi_encoder/utils/constants.ts
@@ -1,3 +1,5 @@
+import * as ethUtil from 'ethereumjs-util';
+
 import { DecodingRules, EncodingRules } from './rules';
 
 export const constants = {
@@ -14,4 +16,8 @@ export const constants = {
     DEFAULT_DECODING_RULES: { shouldConvertStructsToObjects: true } as DecodingRules,
     DEFAULT_ENCODING_RULES: { shouldOptimize: true, shouldAnnotate: false } as EncodingRules,
     /* tslint:enable no-object-literal-type-assertion */
+    EMPTY_EVM_WORD_STRING: '0x0000000000000000000000000000000000000000000000000000000000000000',
+    EMPTY_EVM_WORD_BUFFER: ethUtil.toBuffer('0x0000000000000000000000000000000000000000000000000000000000000000'),
+    NUMBER_OF_BYTES_IN_UINT8: 8,
+    NUMBER_OF_BYTES_IN_INT8: 8,
 };
diff --git a/packages/utils/test/abi_encoder/abi_samples/return_value_abis.ts b/packages/utils/test/abi_encoder/abi_samples/return_value_abis.ts
@@ -97,3 +97,28 @@ export const mixedStaticAndDynamicReturnValues: MethodAbi = {
     stateMutability: 'nonpayable',
     type: 'function',
 };
+
+export const structuredReturnValue: MethodAbi = {
+    constant: false,
+    inputs: [],
+    name: 'fillOrder',
+    outputs: [
+        {
+            components: [
+                {
+                    name: 'makerAssetFilledAmount',
+                    type: 'uint256',
+                },
+                {
+                    name: 'takerAssetFilledAmount',
+                    type: 'uint256',
+                },
+            ],
+            name: 'fillResults',
+            type: 'tuple',
+        },
+    ],
+    payable: false,
+    stateMutability: 'nonpayable',
+    type: 'function',
+};