Add strictArgumentEncodingCheck to BaseContract and use it in contract templates

11 files changed, 319 insertions, 9 deletions

diff --git a/packages/0x.js/test/0x.js_test.ts b/packages/0x.js/test/0x.js_test.ts
index b4baecb1e..2c1cb2c74 100644
--- a/packages/0x.js/test/0x.js_test.ts
+++ b/packages/0x.js/test/0x.js_test.ts
@@ -48,8 +48,9 @@ describe('ZeroEx library', () => {
         const ethSignSignature =
             '0x1B61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc3340349190569279751135161d22529dc25add4f6069af05be04cacbda2ace225403';
         const address = '0x5409ed021d9299bf6814279a6a1411a7e866a631';
+        const bytes32Zeros = '0x0000000000000000000000000000000000000000000000000000000000000000';
         it("should return false if the data doesn't pertain to the signature & address", async () => {
-            return expect((zeroEx.exchange as any).isValidSignatureAsync('0x0', address, ethSignSignature)).to.become(
+            return expect((zeroEx.exchange as any).isValidSignatureAsync(bytes32Zeros, address, ethSignSignature)).to.become(
                 false,
             );
         });
diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
index a240fb8b6..e354f109e 100644
--- a/packages/base-contract/src/index.ts
+++ b/packages/base-contract/src/index.ts
@@ -82,6 +82,23 @@ export class BaseContract {
         }
         return txDataWithDefaults;
     }
+    // Throws if the given arguments cannot be safely/correctly encoded based on
+    // the given inputAbi. An argument may not be considered safely encodeable
+    // if it overflows the corresponding Solidity type, there is a bug in the
+    // encoder, or the encoder performs unsafe type coercion.
+    public static strictArgumentEncodingCheck(inputAbi: DataItem[], args: any[]): void {
+        const coder = (ethers as any).utils.AbiCoder.defaultCoder;
+        const params = abiUtils.parseEthersParams(inputAbi);
+        const rawEncoded = coder.encode(params.names, params.types, args);
+        const rawDecoded = coder.decode(params.names, params.types, rawEncoded);
+        for (let i = 0; i < rawDecoded.length; i++) {
+            const original = args[i];
+            const decoded = rawDecoded[i];
+            if (!abiUtils.isAbiDataEqual(params.names[i], params.types[i], original, decoded)) {
+                throw new Error(`Cannot safely encode argument: ${params.names[i]} (${original}) of type ${params.types[i]}. (Possible type overflow or other encoding error)`);
+            }
+        }
+    }
     protected _lookupEthersInterface(functionSignature: string): ethers.Interface {
         const ethersInterface = this._ethersInterfacesByFunctionSignature[functionSignature];
         if (_.isUndefined(ethersInterface)) {
diff --git a/packages/base-contract/test/base_contract_test.ts b/packages/base-contract/test/base_contract_test.ts
new file mode 100644
index 000000000..57aacdc8a
--- /dev/null
+++ b/packages/base-contract/test/base_contract_test.ts
@@ -0,0 +1,110 @@
+import * as chai from 'chai';
+import 'mocha';
+
+import { BaseContract } from '../src';
+
+const { expect } = chai;
+
+describe('BaseContract', () => {
+    describe('strictArgumentEncodingCheck', () => {
+        it('works for simple types', () => {
+            BaseContract.strictArgumentEncodingCheck([{ name: 'to', type: 'address' }], ['0xe834ec434daba538cd1b9fe1582052b880bd7e63']);
+        });
+        it('works for array types', () => {
+            const inputAbi = [{
+                name: 'takerAssetFillAmounts',
+                type: 'uint256[]',
+            }];
+            const args = [
+                [
+                    '9000000000000000000',
+                    '79000000000000000000',
+                    '979000000000000000000',
+                    '7979000000000000000000',
+                ],
+            ];
+            BaseContract.strictArgumentEncodingCheck(inputAbi, args);
+        });
+        it('works for tuple/struct types', () => {
+            const inputAbi = [
+                {
+                    components: [
+                        {
+                            name: 'makerAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'takerAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'feeRecipientAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'senderAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'makerAssetAmount',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'takerAssetAmount',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'makerFee',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'takerFee',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'expirationTimeSeconds',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'salt',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'makerAssetData',
+                            type: 'bytes',
+                        },
+                        {
+                            name: 'takerAssetData',
+                            type: 'bytes',
+                        },
+                    ],
+                    name: 'order',
+                    type: 'tuple',
+                },
+            ];
+            const args = [
+                {
+                    makerAddress: '0x6ecbe1db9ef729cbe972c83fb886247691fb6beb',
+                    takerAddress: '0x0000000000000000000000000000000000000000',
+                    feeRecipientAddress: '0xe834ec434daba538cd1b9fe1582052b880bd7e63',
+                    senderAddress: '0x0000000000000000000000000000000000000000',
+                    makerAssetAmount: '0',
+                    takerAssetAmount: '200000000000000000000',
+                    makerFee: '1000000000000000000',
+                    takerFee: '1000000000000000000',
+                    expirationTimeSeconds: '1532563026',
+                    salt: '59342956082154660870994022243365949771115859664887449740907298019908621891376',
+                    makerAssetData: '0xf47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48',
+                    takerAssetData: '0xf47261b00000000000000000000000001d7022f5b17d2f8b695918fb48fa1089c9f85401',
+                },
+            ];
+            BaseContract.strictArgumentEncodingCheck(inputAbi, args);
+        });
+        it('throws for integer overflows', () => {
+            expect(() => BaseContract.strictArgumentEncodingCheck([{ name: 'amount', type: 'uint8' }], ['256'])).to.throw();
+        });
+        it('throws for fixed byte array overflows', () => {
+            expect(() => BaseContract.strictArgumentEncodingCheck([{ name: 'hash', type: 'bytes8' }], ['0x001122334455667788'])).to.throw();
+        });
+    });
+});
diff --git a/packages/contract_templates/partials/callAsync.handlebars b/packages/contract_templates/partials/callAsync.handlebars
index fcaae57c6..94752691d 100644
--- a/packages/contract_templates/partials/callAsync.handlebars
+++ b/packages/contract_templates/partials/callAsync.handlebars
@@ -7,6 +7,7 @@ async callAsync(
     const functionSignature = '{{this.functionSignature}}';
     const inputAbi = self._lookupAbi(functionSignature).inputs;
     [{{> params inputs=inputs}}] = BaseContract._formatABIDataItemList(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(self));
+    BaseContract.strictArgumentEncodingCheck(inputAbi, [{{> params inputs=inputs}}]);
     const ethersFunction = self._lookupEthersInterface(functionSignature).functions.{{this.name}}(
         {{> params inputs=inputs}}
     ) as ethers.CallDescription;
diff --git a/packages/contract_templates/partials/tx.handlebars b/packages/contract_templates/partials/tx.handlebars
index e297d05e6..4340d662e 100644
--- a/packages/contract_templates/partials/tx.handlebars
+++ b/packages/contract_templates/partials/tx.handlebars
@@ -11,6 +11,7 @@ public {{this.tsName}} = {
         const self = this as any as {{contractName}}Contract;
         const inputAbi = self._lookupAbi('{{this.functionSignature}}').inputs;
         [{{> params inputs=inputs}}] = BaseContract._formatABIDataItemList(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(self));
+        BaseContract.strictArgumentEncodingCheck(inputAbi, [{{> params inputs=inputs}}]);
         const encodedData = self._lookupEthersInterface('{{this.functionSignature}}').functions.{{this.name}}(
             {{> params inputs=inputs}}
         ).data;
diff --git a/packages/contracts/test/exchange/signature_validator.ts b/packages/contracts/test/exchange/signature_validator.ts
index f2bb42c75..bef0547bd 100644
--- a/packages/contracts/test/exchange/signature_validator.ts
+++ b/packages/contracts/test/exchange/signature_validator.ts
@@ -113,7 +113,7 @@ describe('MixinSignatureValidator', () => {
 
         it('should revert when signature type is unsupported', async () => {
             const unsupportedSignatureType = SignatureType.NSignatureTypes;
-            const unsupportedSignatureHex = `0x${unsupportedSignatureType}`;
+            const unsupportedSignatureHex = '0x' + Buffer.from([unsupportedSignatureType]).toString('hex');
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
             return expectContractCallFailed(
                 signatureValidator.publicIsValidSignature.callAsync(
@@ -126,7 +126,7 @@ describe('MixinSignatureValidator', () => {
         });
 
         it('should revert when SignatureType=Illegal', async () => {
-            const unsupportedSignatureHex = `0x${SignatureType.Illegal}`;
+            const unsupportedSignatureHex = '0x' + Buffer.from([SignatureType.Illegal]).toString('hex');
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
             return expectContractCallFailed(
                 signatureValidator.publicIsValidSignature.callAsync(
@@ -139,7 +139,7 @@ describe('MixinSignatureValidator', () => {
         });
 
         it('should return false when SignatureType=Invalid and signature has a length of zero', async () => {
-            const signatureHex = `0x${SignatureType.Invalid}`;
+            const signatureHex = '0x' + Buffer.from([SignatureType.Invalid]).toString('hex');
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
             const isValidSignature = await signatureValidator.publicIsValidSignature.callAsync(
                 orderHashHex,
diff --git a/packages/order-utils/test/signature_utils_test.ts b/packages/order-utils/test/signature_utils_test.ts
index 5714f9671..baae2b414 100644
--- a/packages/order-utils/test/signature_utils_test.ts
+++ b/packages/order-utils/test/signature_utils_test.ts
@@ -22,7 +22,8 @@ describe('Signature utils', () => {
         let address = '0x5409ed021d9299bf6814279a6a1411a7e866a631';
 
         it("should return false if the data doesn't pertain to the signature & address", async () => {
-            expect(await isValidSignatureAsync(provider, '0x0', ethSignSignature, address)).to.be.false();
+            const bytes32Zeros = '0x0000000000000000000000000000000000000000000000000000000000000000';
+            expect(await isValidSignatureAsync(provider, bytes32Zeros, ethSignSignature, address)).to.be.false();
         });
         it("should return false if the address doesn't pertain to the signature & data", async () => {
             const validUnrelatedAddress = '0x8b0292b11a196601ed2ce54b665cafeca0347d42';
diff --git a/packages/utils/package.json b/packages/utils/package.json
index ee150cb0e..46c1d05d0 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -5,12 +5,13 @@
         "node": ">=6.12"
     },
     "description": "0x TS utils",
-    "main": "lib/index.js",
-    "types": "lib/index.d.ts",
+    "main": "lib/src/index.js",
+    "types": "lib/src/index.d.ts",
     "scripts": {
         "watch_without_deps": "tsc -w",
         "build": "tsc && copyfiles -u 2 './lib/monorepo_scripts/**/*' ./scripts",
         "clean": "shx rm -rf lib scripts",
+        "test": "mocha --require source-map-support/register --require make-promises-safe lib/test/**/*_test.js --bail --exit",
         "lint": "tslint --project .",
         "manual:postpublish": "yarn build; node ./scripts/postpublish.js"
     },
@@ -27,12 +28,15 @@
         "@0xproject/monorepo-scripts": "^1.0.4",
         "@0xproject/tslint-config": "^1.0.4",
         "@types/lodash": "4.14.104",
+        "@types/mocha": "^2.2.42",
         "copyfiles": "^1.2.0",
         "make-promises-safe": "^1.1.0",
         "npm-run-all": "^4.1.2",
         "shx": "^0.2.2",
         "tslint": "5.11.0",
-        "typescript": "2.9.2"
+        "typescript": "2.9.2",
+        "chai": "^4.0.1",
+        "mocha": "^4.0.1"
     },
     "dependencies": {
         "@0xproject/types": "^1.0.1-rc.3",
diff --git a/packages/utils/src/abi_utils.ts b/packages/utils/src/abi_utils.ts
index 421dd405c..16aa72afd 100644
--- a/packages/utils/src/abi_utils.ts
+++ b/packages/utils/src/abi_utils.ts
@@ -1,7 +1,160 @@
 import { AbiDefinition, AbiType, ContractAbi, DataItem, MethodAbi } from 'ethereum-types';
 import * as _ from 'lodash';
 
+import { BigNumber } from './configured_bignumber';
+
+export type EthersParamName = null | string | EthersNestedParamName;
+
+export interface EthersNestedParamName {
+    name: string | null;
+    names: EthersParamName[];
+}
+
+// Note(albrow): This function is unexported in ethers.js. Copying it here for
+// now.
+// Source: https://github.com/ethers-io/ethers.js/blob/884593ab76004a808bf8097e9753fb5f8dcc3067/contracts/interface.js#L30
+function parseEthersParams(params: DataItem[]): { names: EthersParamName[]; types: string[] } {
+    const names: EthersParamName[] = [];
+    const types: string[] = [];
+
+    params.forEach((param: DataItem) => {
+        if (param.components != null) {
+            let suffix = '';
+            const arrayBracket = param.type.indexOf('[');
+            if (arrayBracket >= 0) { suffix = param.type.substring(arrayBracket); }
+
+            const result = parseEthersParams(param.components);
+            names.push({ name: (param.name || null), names: result.names });
+            types.push('tuple(' + result.types.join(',') + ')' + suffix);
+        } else {
+            names.push(param.name || null);
+            types.push(param.type);
+        }
+    });
+
+    return {
+        names,
+        types,
+    };
+}
+
+// returns true if x is equal to y and false otherwise. Performs some minimal
+// type conversion and data massaging for x and y, depending on type. name and
+// type should typically be derived from parseEthersParams.
+function isAbiDataEqual(name: EthersParamName, type: string, x: any, y: any): boolean {
+    if (_.isUndefined(x) && _.isUndefined(y)) {
+        return true;
+    } else if (_.isUndefined(x) && !_.isUndefined(y)) {
+        return false;
+    } else if (!_.isUndefined(x) && _.isUndefined(y)) {
+        return false;
+    }
+    if (_.endsWith(type, '[]')) {
+        // For array types, we iterate through the elements and check each one
+        // individually. Strangely, name does not need to be changed in this
+        // case.
+        if (x.length !== y.length) {
+            return false;
+        }
+        const newType = _.trimEnd(type, '[]');
+        for (let i = 0; i < x.length; i++) {
+            if (!isAbiDataEqual(name, newType, x[i], y[i])) {
+                return false;
+            }
+        }
+        return true;
+    }
+    if (_.startsWith(type, 'tuple(')) {
+        if (_.isString(name)) {
+            throw new Error('Internal error: type was tuple but names was a string');
+        } else if (_.isNull(name)) {
+            throw new Error('Internal error: type was tuple but names was a null');
+        }
+        // For tuples, we iterate through the underlying values and check each
+        // one individually.
+        const types = splitTupleTypes(type);
+        if (types.length !== name.names.length) {
+            throw new Error(`Internal error: parameter types/names length mismatch (${types.length} != ${name.names.length})`);
+        }
+        for (let i = 0; i < types.length; i++) {
+            // For tuples, name is an object with a names property that is an
+            // array. As an example, for orders, name looks like:
+            //
+            //  {
+            //      name: 'orders',
+            //      names: [
+            //          'makerAddress',
+            //          // ...
+            //          'takerAssetData'
+            //      ]
+            //  }
+            //
+            const nestedName = _.isString(name.names[i]) ? name.names[i] as string : (name.names[i] as EthersNestedParamName).name as string;
+            if (!isAbiDataEqual(name.names[i], types[i], x[nestedName], y[nestedName])) {
+                return false;
+            }
+        }
+        return true;
+    } else if (type === 'address' || type === 'bytes') {
+        // HACK(albrow): ethers.js sometimes changes the case of addresses/bytes
+        // when decoding/encoding. To account for that, we convert to lowercase
+        // before comparing.
+        return _.isEqual(_.toLower(x), _.toLower(y));
+    } else if (_.startsWith(type, 'uint') || _.startsWith(type, 'int')) {
+        return new BigNumber(x).eq(new BigNumber(y));
+    }
+    return _.isEqual(x, y);
+}
+
+// splitTupleTypes splits a tuple type string (of the form `tuple(X)` where X is
+// any other type or list of types) into its component types. It works with
+// nested tuples, so, e.g., `tuple(tuple(uint256,address),bytes32)` will yield:
+// `['tuple(uint256,address)', 'bytes32']`. It expects exactly one tuple type as
+// an argument (not an array).
+function splitTupleTypes(type: string): string[] {
+    if (_.endsWith(type, '[]')) {
+        throw new Error('Internal error: array types are not supported');
+    } else if (!_.startsWith(type, 'tuple(')) {
+        throw new Error('Internal error: expected tuple type but got non-tuple type: ' + type);
+    }
+    // Trim the outtermost tuple().
+    const trimmedType = type.substring('tuple('.length, type.length - 1);
+    const types: string[] = [];
+    let currToken = '';
+    let parenCount = 0;
+    // Tokenize the type string while keeping track of parentheses.
+    for (const char of trimmedType) {
+        switch (char) {
+            case '(':
+                parenCount += 1;
+                currToken += char;
+                break;
+            case ')':
+                parenCount -= 1;
+                currToken += char;
+                break;
+            case ',':
+                if (parenCount === 0) {
+                    types.push(currToken);
+                    currToken = '';
+                    break;
+                } else {
+                    currToken += char;
+                    break;
+                }
+            default:
+                currToken += char;
+                break;
+        }
+    }
+    types.push(currToken);
+    return types;
+}
+
 export const abiUtils = {
+    parseEthersParams,
+    isAbiDataEqual,
+    splitTupleTypes,
     parseFunctionParam(param: DataItem): string {
         if (param.type === 'tuple') {
             // Parse out tuple types into {type_1, type_2, ..., type_N}
diff --git a/packages/utils/test/abi_utils_test.ts b/packages/utils/test/abi_utils_test.ts
new file mode 100644
index 000000000..0ebee64c4
--- /dev/null
+++ b/packages/utils/test/abi_utils_test.ts
@@ -0,0 +1,19 @@
+import * as chai from 'chai';
+import 'mocha';
+
+import { abiUtils } from '../src';
+
+const expect = chai.expect;
+
+describe('abiUtils', () => {
+    describe('splitTupleTypes', () => {
+        it('handles basic types', () => {
+            const got = abiUtils.splitTupleTypes('tuple(bytes,uint256,address)');
+            expect(got).to.deep.equal(['bytes', 'uint256', 'address']);
+        });
+        it('handles nested tuple types', () => {
+            const got = abiUtils.splitTupleTypes('tuple(tuple(bytes,uint256),address)');
+            expect(got).to.deep.equal(['tuple(bytes,uint256)', 'address']);
+        });
+    });
+});
diff --git a/packages/utils/tsconfig.json b/packages/utils/tsconfig.json
index c56d255d5..852708eba 100644
--- a/packages/utils/tsconfig.json
+++ b/packages/utils/tsconfig.json
@@ -3,5 +3,8 @@
     "compilerOptions": {
         "outDir": "lib"
     },
-    "include": ["./src/**/*"]
+    "include": [
+        "src/**/*",
+        "test/**/*"
+    ]
 }