Merge development

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diff --git a/contracts/test-utils/src/combinatorial_utils.ts b/contracts/test-utils/src/combinatorial_utils.ts
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+++ b/contracts/test-utils/src/combinatorial_utils.ts
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+import { BigNumber } from '@0x/utils';
+import * as combinatorics from 'js-combinatorics';
+
+import { testWithReferenceFuncAsync } from './test_with_reference';
+
+// A set of values corresponding to the uint256 type in Solidity. This set
+// contains some notable edge cases, including some values which will overflow
+// the uint256 type when used in different mathematical operations.
+export const uint256Values = [
+    new BigNumber(0),
+    new BigNumber(1),
+    new BigNumber(2),
+    // Non-trivial big number.
+    new BigNumber(2).pow(64),
+    // Max that does not overflow when squared.
+    new BigNumber(2).pow(128).minus(1),
+    // Min that does overflow when squared.
+    new BigNumber(2).pow(128),
+    // Max that does not overflow when doubled.
+    new BigNumber(2).pow(255).minus(1),
+    // Min that does overflow when doubled.
+    new BigNumber(2).pow(255),
+    // Max that does not overflow.
+    new BigNumber(2).pow(256).minus(1),
+];
+
+// A set of values corresponding to the bytes32 type in Solidity.
+export const bytes32Values = [
+    // Min
+    '0x0000000000000000000000000000000000000000000000000000000000000000',
+    '0x0000000000000000000000000000000000000000000000000000000000000001',
+    '0x0000000000000000000000000000000000000000000000000000000000000002',
+    // Non-trivial big number.
+    '0x000000000000f000000000000000000000000000000000000000000000000000',
+    // Max
+    '0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff',
+];
+
+export async function testCombinatoriallyWithReferenceFuncAsync<P0, P1, R>(
+    name: string,
+    referenceFunc: (p0: P0, p1: P1) => Promise<R>,
+    testFunc: (p0: P0, p1: P1) => Promise<R>,
+    allValues: [P0[], P1[]],
+): Promise<void>;
+export async function testCombinatoriallyWithReferenceFuncAsync<P0, P1, P2, R>(
+    name: string,
+    referenceFunc: (p0: P0, p1: P1, p2: P2) => Promise<R>,
+    testFunc: (p0: P0, p1: P1, p2: P2) => Promise<R>,
+    allValues: [P0[], P1[], P2[]],
+): Promise<void>;
+export async function testCombinatoriallyWithReferenceFuncAsync<P0, P1, P2, P3, R>(
+    name: string,
+    referenceFunc: (p0: P0, p1: P1, p2: P2, p3: P3) => Promise<R>,
+    testFunc: (p0: P0, p1: P1, p2: P2, p3: P3) => Promise<R>,
+    allValues: [P0[], P1[], P2[], P3[]],
+): Promise<void>;
+export async function testCombinatoriallyWithReferenceFuncAsync<P0, P1, P2, P3, P4, R>(
+    name: string,
+    referenceFunc: (p0: P0, p1: P1, p2: P2, p3: P3, p4: P4) => Promise<R>,
+    testFunc: (p0: P0, p1: P1, p2: P2, p3: P3, p4: P4) => Promise<R>,
+    allValues: [P0[], P1[], P2[], P3[], P4[]],
+): Promise<void>;
+
+/**
+ * Uses combinatorics to test the behavior of a test function by comparing it to
+ * the expected behavior (defined by a reference function) for a large number of
+ * possible input values.
+ *
+ * First generates test cases by taking the cartesian product of the given
+ * values. Each test case is a set of N values corresponding to the N arguments
+ * for the test func and the reference func. For each test case, first the
+ * reference function will be called to obtain an "expected result", or if the
+ * reference function throws/rejects, an "expected error". Next, the test
+ * function will be called to obtain an "actual result", or if the test function
+ * throws/rejects, an "actual error". Each test case passes if at least one of
+ * the following conditions is met:
+ *
+ * 1) Neither the reference function or the test function throw and the
+ * "expected result" equals the "actual result".
+ *
+ * 2) Both the reference function and the test function throw and the "actual
+ * error" message *contains* the "expected error" message.
+ *
+ * The first test case which does not meet one of these conditions will cause
+ * the entire test to fail and this function will throw/reject.
+ *
+ * @param referenceFuncAsync a reference function implemented in pure
+ * JavaScript/TypeScript which accepts N arguments and returns the "expected
+ * result" or "expected error" for a given test case.
+ * @param testFuncAsync a test function which, e.g., makes a call or sends a
+ * transaction to a contract. It accepts the same N arguments returns the
+ * "actual result" or "actual error" for a given test case.
+ * @param values an array of N arrays. Each inner array is a set of possible
+ * values which are passed into both the reference function and the test
+ * function.
+ * @return A Promise that resolves if the test passes and rejects if the test
+ * fails, according to the rules described above.
+ */
+export async function testCombinatoriallyWithReferenceFuncAsync(
+    name: string,
+    referenceFuncAsync: (...args: any[]) => Promise<any>,
+    testFuncAsync: (...args: any[]) => Promise<any>,
+    allValues: any[],
+): Promise<void> {
+    const testCases = combinatorics.cartesianProduct(...allValues);
+    let counter = 0;
+    testCases.forEach(async testCase => {
+        counter += 1;
+        it(`${name} ${counter}/${testCases.length}`, async () => {
+            await testWithReferenceFuncAsync(referenceFuncAsync, testFuncAsync, testCase as any);
+        });
+    });
+}