@0x/contracts-exchange-libs: Add explicit tests for LibMath and LibFillResults functions.

`@0x/contracts-exchange-libs`: Add tests for `ReferenceFunctions`.

contracts/exchange-libs/test/lib_fill_results.ts

@@ -1,16 +1,17 @@
 import {
     blockchainTests,
+    constants,
     describe,
-    testCombinatoriallyWithReferenceFunc,
-    uint256Values,
+    expect,
 } from '@0x/contracts-test-utils';
-import { FillResults } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, SafeMathRevertErrors } from '@0x/utils';
+import * as _ from 'lodash';
 
 import { artifacts, ReferenceFunctions, TestLibsContract } from '../src';
 
 blockchainTests('LibFillResults', env => {
     const CHAIN_ID = 1337;
+    const { ONE_ETHER, MAX_UINT256 } = constants;
     let libsContract: TestLibsContract;
 
     before(async () => {
@@ -23,47 +24,76 @@ blockchainTests('LibFillResults', env => {
     });
 
     describe('addFillResults', () => {
-        function makeFillResults(value: BigNumber): FillResults {
-            // HACK(dorothy-zbornak): We reuse values across fields,
-            // but this is fine because `addFillResults()` never does
-            // any math between them.
-            return {
-                makerAssetFilledAmount: value,
-                takerAssetFilledAmount: value,
-                makerFeePaid: value,
-                takerFeePaid: value,
-            };
-        }
+        describe('explicit tests', () => {
+            const DEFAULT_FILL_RESULTS = [
+                {
+                    makerAssetFilledAmount: ONE_ETHER,
+                    takerAssetFilledAmount: ONE_ETHER.times(2),
+                    makerFeePaid: ONE_ETHER.times(0.001),
+                    takerFeePaid: ONE_ETHER.times(0.002),
+                },
+                {
+                    makerAssetFilledAmount: ONE_ETHER.times(0.01),
+                    takerAssetFilledAmount: ONE_ETHER.times(2).times(0.01),
+                    makerFeePaid: ONE_ETHER.times(0.001).times(0.01),
+                    takerFeePaid: ONE_ETHER.times(0.002).times(0.01),
+                },
+            ];
 
-        async function referenceAddFillResultsAsync(
-            totalValue: BigNumber,
-            singleValue: BigNumber,
-        ): Promise<FillResults> {
-            return ReferenceFunctions.addFillResults(
-                makeFillResults(totalValue),
-                makeFillResults(singleValue),
-            );
-        }
+            it('matches the output of the reference function', async () => {
+                const [ a, b ] = DEFAULT_FILL_RESULTS;
+                const expected = ReferenceFunctions.addFillResults(a, b);
+                const actual = await libsContract.addFillResults.callAsync(a, b);
+                expect(actual).to.deep.equal(expected);
+            });
 
-        async function testAddFillResultsAsync(
-            totalValue: BigNumber,
-            singleValue: BigNumber,
-        ): Promise<FillResults> {
-            return libsContract.addFillResults.callAsync(
-                makeFillResults(totalValue),
-                makeFillResults(singleValue),
-            );
-        }
+            it('reverts if computing `makerAssetFilledAmount` overflows', async () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.makerAssetFilledAmount = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.makerAssetFilledAmount,
+                    b.makerAssetFilledAmount,
+                );
+                return expect(libsContract.addFillResults.callAsync(a, b))
+                    .to.revertWith(expectedError);
+            });
 
-        // TODO(dorothy-zbornak): Do we really need these?
-        // Just a couple edge cases would likely suffice.
-        describe.optional('combinatorial tests', () => {
-            testCombinatoriallyWithReferenceFunc(
-                'addFillResults',
-                referenceAddFillResultsAsync,
-                testAddFillResultsAsync,
-                [uint256Values, uint256Values],
-            );
+            it('reverts if computing `takerAssetFilledAmount` overflows', async () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.takerAssetFilledAmount = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.takerAssetFilledAmount,
+                    b.takerAssetFilledAmount,
+                );
+                return expect(libsContract.addFillResults.callAsync(a, b))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if computing `makerFeePaid` overflows', async () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.makerFeePaid = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.makerFeePaid,
+                    b.makerFeePaid,
+                );
+                return expect(libsContract.addFillResults.callAsync(a, b))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if computing `takerFeePaid` overflows', async () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.takerFeePaid = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.takerFeePaid,
+                    b.takerFeePaid,
+                );
+                return expect(libsContract.addFillResults.callAsync(a, b))
+                    .to.revertWith(expectedError);
+            });
         });
     });
 });

contracts/exchange-libs/test/lib_math.ts

@@ -1,15 +1,19 @@
 import {
     blockchainTests,
+    constants,
     describe,
+    expect,
     testCombinatoriallyWithReferenceFunc,
     uint256Values,
 } from '@0x/contracts-test-utils';
-import { BigNumber } from '@0x/utils';
+import { LibMathRevertErrors } from '@0x/order-utils';
+import { BigNumber, SafeMathRevertErrors } from '@0x/utils';
 
 import { artifacts, ReferenceFunctions, TestLibsContract } from '../src';
 
 blockchainTests('LibMath', env => {
     const CHAIN_ID = 1337;
+    const { ONE_ETHER, MAX_UINT256, MAX_UINT256_ROOT, ZERO_AMOUNT } = constants;
     let libsContract: TestLibsContract;
 
     before(async () => {
@@ -48,6 +52,43 @@ blockchainTests('LibMath', env => {
                 [uint256Values, uint256Values, uint256Values],
             );
         });
+
+        describe('explicit tests', () => {
+            it('matches the reference function output', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = ONE_ETHER.times(0.01);
+                const expected = ReferenceFunctions.getPartialAmountFloor(numerator, denominator, target);
+                const actual = await libsContract.getPartialAmountFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.bignumber.eq(expected);
+            });
+
+            it('reverts if `denominator` is zero', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ZERO_AMOUNT;
+                const target = ONE_ETHER.times(0.01);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256DivisionByZero,
+                    numerator.times(target),
+                    denominator,
+                );
+                return expect(libsContract.getPartialAmountFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `numerator * target` overflows', async () => {
+                const numerator = MAX_UINT256;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = MAX_UINT256_ROOT.times(2);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                    numerator,
+                    target,
+                );
+                return expect(libsContract.getPartialAmountFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+        });
     });
 
     describe('getPartialAmountCeil', () => {
@@ -59,6 +100,44 @@ blockchainTests('LibMath', env => {
                 [uint256Values, uint256Values, uint256Values],
             );
         });
+
+        describe('explicit tests', () => {
+            it('matches the reference function output', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = ONE_ETHER.times(0.01);
+                const expected = ReferenceFunctions.getPartialAmountCeil(numerator, denominator, target);
+                const actual = await libsContract.getPartialAmountCeil.callAsync(numerator, denominator, target);
+                expect(actual).to.bignumber.eq(expected);
+            });
+
+            it('reverts if `denominator` is zero', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ZERO_AMOUNT;
+                const target = ONE_ETHER.times(0.01);
+                // This will actually manifest as a subtraction underflow.
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256SubtractionUnderflow,
+                    denominator,
+                    new BigNumber(1),
+                );
+                return expect(libsContract.getPartialAmountCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `numerator * target` overflows', async () => {
+                const numerator = MAX_UINT256;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = MAX_UINT256_ROOT.times(2);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                    numerator,
+                    target,
+                );
+                return expect(libsContract.getPartialAmountCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+        });
     });
 
     describe('safeGetPartialAmountFloor', () => {
@@ -70,6 +149,52 @@ blockchainTests('LibMath', env => {
                 [uint256Values, uint256Values, uint256Values],
             );
         });
+
+        describe('explicit tests', () => {
+            it('matches the reference function output', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = ONE_ETHER.times(0.01);
+                const expected = ReferenceFunctions.safeGetPartialAmountFloor(numerator, denominator, target);
+                const actual = await libsContract.safeGetPartialAmountFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.bignumber.eq(expected);
+            });
+
+            it('reverts for a rounding error', async () => {
+                const numerator = new BigNumber(1e3);
+                const denominator = new BigNumber(1e4);
+                const target = new BigNumber(333);
+                const expectedError = new LibMathRevertErrors.RoundingError(
+                    numerator,
+                    denominator,
+                    target,
+                );
+                return expect(libsContract.safeGetPartialAmountFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `denominator` is zero', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ZERO_AMOUNT;
+                const target = ONE_ETHER.times(0.01);
+                const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                return expect(libsContract.safeGetPartialAmountFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `numerator * target` overflows', async () => {
+                const numerator = MAX_UINT256;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = MAX_UINT256_ROOT.times(2);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                    numerator,
+                    target,
+                );
+                return expect(libsContract.safeGetPartialAmountFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+        });
     });
 
     describe('safeGetPartialAmountCeil', () => {
@@ -81,6 +206,52 @@ blockchainTests('LibMath', env => {
                 [uint256Values, uint256Values, uint256Values],
             );
         });
+
+        describe('explicit tests', () => {
+            it('matches the reference function output', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = ONE_ETHER.times(0.01);
+                const expected = ReferenceFunctions.safeGetPartialAmountCeil(numerator, denominator, target);
+                const actual = await libsContract.safeGetPartialAmountCeil.callAsync(numerator, denominator, target);
+                expect(actual).to.bignumber.eq(expected);
+            });
+
+            it('reverts for a rounding error', async () => {
+                const numerator = new BigNumber(1e3);
+                const denominator = new BigNumber(1e4);
+                const target = new BigNumber(333);
+                const expectedError = new LibMathRevertErrors.RoundingError(
+                    numerator,
+                    denominator,
+                    target,
+                );
+                return expect(libsContract.safeGetPartialAmountCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `denominator` is zero', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ZERO_AMOUNT;
+                const target = ONE_ETHER.times(0.01);
+                const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                return expect(libsContract.safeGetPartialAmountCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `numerator * target` overflows', async () => {
+                const numerator = MAX_UINT256;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = MAX_UINT256_ROOT.times(2);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                    numerator,
+                    target,
+                );
+                return expect(libsContract.safeGetPartialAmountCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+        });
     });
 
     describe('isRoundingErrorFloor', () => {
@@ -92,6 +263,55 @@ blockchainTests('LibMath', env => {
                 [uint256Values, uint256Values, uint256Values],
             );
         });
+
+        describe('explicit tests', () => {
+            it('returns true for a rounding error', async () => {
+                const numerator = new BigNumber(1e3);
+                const denominator = new BigNumber(1e4);
+                const target = new BigNumber(333);
+                const actual = await libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.eq(true);
+            });
+
+            it('returns false for not a rounding error', async () => {
+                const numerator = new BigNumber(1e3);
+                const denominator = new BigNumber(1e4);
+                const target = new BigNumber(5e2);
+                const actual = await libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.eq(false);
+            });
+
+            it('matches the reference function output', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = ONE_ETHER.times(0.01);
+                const expected = ReferenceFunctions.isRoundingErrorFloor(numerator, denominator, target);
+                const actual = await libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.eq(expected);
+            });
+
+            it('reverts if `denominator` is zero', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ZERO_AMOUNT;
+                const target = ONE_ETHER.times(0.01);
+                const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                return expect(libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `numerator * target` overflows', async () => {
+                const numerator = MAX_UINT256;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = MAX_UINT256_ROOT.times(2);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                    numerator,
+                    target,
+                );
+                return expect(libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+        });
     });
 
     describe('isRoundingErrorCeil', () => {
@@ -103,5 +323,54 @@ blockchainTests('LibMath', env => {
                 [uint256Values, uint256Values, uint256Values],
             );
         });
+
+        describe('explicit tests', () => {
+            it('returns true for a rounding error', async () => {
+                const numerator = new BigNumber(1e3);
+                const denominator = new BigNumber(1e4);
+                const target = new BigNumber(333);
+                const actual = await libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.eq(true);
+            });
+
+            it('returns false for not a rounding error', async () => {
+                const numerator = new BigNumber(1e3);
+                const denominator = new BigNumber(1e4);
+                const target = new BigNumber(5e2);
+                const actual = await libsContract.isRoundingErrorFloor.callAsync(numerator, denominator, target);
+                expect(actual).to.eq(false);
+            });
+
+            it('matches the reference function output', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = ONE_ETHER.times(0.01);
+                const expected = ReferenceFunctions.isRoundingErrorCeil(numerator, denominator, target);
+                const actual = await libsContract.isRoundingErrorCeil.callAsync(numerator, denominator, target);
+                expect(actual).to.eq(expected);
+            });
+
+            it('reverts if `denominator` is zero', async () => {
+                const numerator = ONE_ETHER;
+                const denominator = ZERO_AMOUNT;
+                const target = ONE_ETHER.times(0.01);
+                const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                return expect(libsContract.isRoundingErrorCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+
+            it('reverts if `numerator * target` overflows', async () => {
+                const numerator = MAX_UINT256;
+                const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                const target = MAX_UINT256_ROOT.times(2);
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                    numerator,
+                    target,
+                );
+                return expect(libsContract.isRoundingErrorCeil.callAsync(numerator, denominator, target))
+                    .to.revertWith(expectedError);
+            });
+        });
     });
 });

contracts/exchange-libs/test/reference_functions.ts

@@ -0,0 +1,310 @@
+import {
+    constants,
+    describe,
+    expect,
+} from '@0x/contracts-test-utils';
+import { LibMathRevertErrors } from '@0x/order-utils';
+import { BigNumber, SafeMathRevertErrors } from '@0x/utils';
+import * as _ from 'lodash';
+
+import {
+    addFillResults,
+    getPartialAmountCeil,
+    getPartialAmountFloor,
+    isRoundingErrorCeil,
+    isRoundingErrorFloor,
+    safeGetPartialAmountCeil,
+    safeGetPartialAmountFloor,
+} from '../src/reference_functions';
+
+describe('Reference Functions', () => {
+    const { ONE_ETHER, MAX_UINT256, MAX_UINT256_ROOT, ZERO_AMOUNT } = constants;
+    describe('LibFillResults', () => {
+
+        describe('addFillResults', () => {
+            const DEFAULT_FILL_RESULTS = [
+                {
+                    makerAssetFilledAmount: ONE_ETHER,
+                    takerAssetFilledAmount: ONE_ETHER.times(2),
+                    makerFeePaid: ONE_ETHER.times(0.001),
+                    takerFeePaid: ONE_ETHER.times(0.002),
+                },
+                {
+                    makerAssetFilledAmount: ONE_ETHER.times(0.01),
+                    takerAssetFilledAmount: ONE_ETHER.times(2).times(0.01),
+                    makerFeePaid: ONE_ETHER.times(0.001).times(0.01),
+                    takerFeePaid: ONE_ETHER.times(0.002).times(0.01),
+                },
+            ];
+
+            it('reverts if computing `makerAssetFilledAmount` overflows', () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.makerAssetFilledAmount = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.makerAssetFilledAmount,
+                    b.makerAssetFilledAmount,
+                );
+                expect(() => addFillResults(a, b)).to.throw(expectedError.message);
+            });
+
+            it('reverts if computing `takerAssetFilledAmount` overflows', () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.takerAssetFilledAmount = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.takerAssetFilledAmount,
+                    b.takerAssetFilledAmount,
+                );
+                expect(() => addFillResults(a, b)).to.throw(expectedError.message);
+            });
+
+            it('reverts if computing `makerFeePaid` overflows', () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.makerFeePaid = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.makerFeePaid,
+                    b.makerFeePaid,
+                );
+                expect(() => addFillResults(a, b)).to.throw(expectedError.message);
+            });
+
+            it('reverts if computing `takerFeePaid` overflows', () => {
+                const [ a, b ] = _.cloneDeep(DEFAULT_FILL_RESULTS);
+                b.takerFeePaid = MAX_UINT256;
+                const expectedError = new SafeMathRevertErrors.SafeMathError(
+                    SafeMathRevertErrors.SafeMathErrorCodes.Uint256AdditionOverflow,
+                    a.takerFeePaid,
+                    b.takerFeePaid,
+                );
+                expect(() => addFillResults(a, b)).to.throw(expectedError.message);
+            });
+        });
+    });
+
+    describe('LibMath', () => {
+        describe('getPartialAmountFloor', () => {
+            describe('explicit tests', () => {
+                it('reverts if `denominator` is zero', () => {
+                    const numerator = ONE_ETHER;
+                    const denominator = ZERO_AMOUNT;
+                    const target = ONE_ETHER.times(0.01);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256DivisionByZero,
+                        numerator.times(target),
+                        denominator,
+                    );
+                    return expect(() => getPartialAmountFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `numerator * target` overflows', () => {
+                    const numerator = MAX_UINT256;
+                    const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                    const target = MAX_UINT256_ROOT.times(2);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                        numerator,
+                        target,
+                    );
+                    return expect(() => getPartialAmountFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+            });
+        });
+
+        describe('getPartialAmountCeil', () => {
+            describe('explicit tests', () => {
+                it('reverts if `denominator` is zero', () => {
+                    const numerator = ONE_ETHER;
+                    const denominator = ZERO_AMOUNT;
+                    const target = ONE_ETHER.times(0.01);
+                    // This will actually manifest as a subtraction underflow.
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256SubtractionUnderflow,
+                        denominator,
+                        new BigNumber(1),
+                    );
+                    return expect(() => getPartialAmountCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `numerator * target` overflows', () => {
+                    const numerator = MAX_UINT256;
+                    const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                    const target = MAX_UINT256_ROOT.times(2);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                        numerator,
+                        target,
+                    );
+                    return expect(() => getPartialAmountCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+            });
+        });
+
+        describe('safeGetPartialAmountFloor', () => {
+            describe('explicit tests', () => {
+                it('reverts for a rounding error', () => {
+                    const numerator = new BigNumber(1e3);
+                    const denominator = new BigNumber(1e4);
+                    const target = new BigNumber(333);
+                    const expectedError = new LibMathRevertErrors.RoundingError(
+                        numerator,
+                        denominator,
+                        target,
+                    );
+                    return expect(() => safeGetPartialAmountFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `denominator` is zero', () => {
+                    const numerator = ONE_ETHER;
+                    const denominator = ZERO_AMOUNT;
+                    const target = ONE_ETHER.times(0.01);
+                    const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                    return expect(() => safeGetPartialAmountFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `numerator * target` overflows', () => {
+                    const numerator = MAX_UINT256;
+                    const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                    const target = MAX_UINT256_ROOT.times(2);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                        numerator,
+                        target,
+                    );
+                    return expect(() => safeGetPartialAmountFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+            });
+        });
+
+        describe('safeGetPartialAmountCeil', () => {
+            describe('explicit tests', () => {
+                it('reverts for a rounding error', () => {
+                    const numerator = new BigNumber(1e3);
+                    const denominator = new BigNumber(1e4);
+                    const target = new BigNumber(333);
+                    const expectedError = new LibMathRevertErrors.RoundingError(
+                        numerator,
+                        denominator,
+                        target,
+                    );
+                    return expect(() => safeGetPartialAmountCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `denominator` is zero', () => {
+                    const numerator = ONE_ETHER;
+                    const denominator = ZERO_AMOUNT;
+                    const target = ONE_ETHER.times(0.01);
+                    const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                    return expect(() => safeGetPartialAmountCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `numerator * target` overflows', () => {
+                    const numerator = MAX_UINT256;
+                    const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                    const target = MAX_UINT256_ROOT.times(2);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                        numerator,
+                        target,
+                    );
+                    return expect(() => safeGetPartialAmountCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+            });
+        });
+
+        describe('isRoundingErrorFloor', () => {
+            describe('explicit tests', () => {
+                it('returns true for a rounding error', () => {
+                    const numerator = new BigNumber(1e3);
+                    const denominator = new BigNumber(1e4);
+                    const target = new BigNumber(333);
+                    const actual = isRoundingErrorFloor(numerator, denominator, target);
+                    expect(actual).to.eq(true);
+                });
+
+                it('returns false for not a rounding error', () => {
+                    const numerator = new BigNumber(1e3);
+                    const denominator = new BigNumber(1e4);
+                    const target = new BigNumber(5e2);
+                    const actual = isRoundingErrorFloor(numerator, denominator, target);
+                    expect(actual).to.eq(false);
+                });
+
+                it('reverts if `denominator` is zero', () => {
+                    const numerator = ONE_ETHER;
+                    const denominator = ZERO_AMOUNT;
+                    const target = ONE_ETHER.times(0.01);
+                    const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                    return expect(() => isRoundingErrorFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `numerator * target` overflows', () => {
+                    const numerator = MAX_UINT256;
+                    const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                    const target = MAX_UINT256_ROOT.times(2);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                        numerator,
+                        target,
+                    );
+                    return expect(() => isRoundingErrorFloor(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+            });
+        });
+
+        describe('isRoundingErrorCeil', () => {
+            describe('explicit tests', () => {
+                it('returns true for a rounding error', () => {
+                    const numerator = new BigNumber(1e3);
+                    const denominator = new BigNumber(1e4);
+                    const target = new BigNumber(333);
+                    const actual = isRoundingErrorFloor(numerator, denominator, target);
+                    expect(actual).to.eq(true);
+                });
+
+                it('returns false for not a rounding error', () => {
+                    const numerator = new BigNumber(1e3);
+                    const denominator = new BigNumber(1e4);
+                    const target = new BigNumber(5e2);
+                    const actual = isRoundingErrorFloor(numerator, denominator, target);
+                    expect(actual).to.eq(false);
+                });
+
+                it('reverts if `denominator` is zero', () => {
+                    const numerator = ONE_ETHER;
+                    const denominator = ZERO_AMOUNT;
+                    const target = ONE_ETHER.times(0.01);
+                    const expectedError = new LibMathRevertErrors.DivisionByZeroError();
+                    return expect(() => isRoundingErrorCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+
+                it('reverts if `numerator * target` overflows', () => {
+                    const numerator = MAX_UINT256;
+                    const denominator = ONE_ETHER.dividedToIntegerBy(2);
+                    const target = MAX_UINT256_ROOT.times(2);
+                    const expectedError = new SafeMathRevertErrors.SafeMathError(
+                        SafeMathRevertErrors.SafeMathErrorCodes.Uint256MultiplicationOverflow,
+                        numerator,
+                        target,
+                    );
+                    return expect(() => isRoundingErrorCeil(numerator, denominator, target))
+                        .to.throw(expectedError.message);
+                });
+            });
+        });
+    });
+});