@0x/utils: Fix FixedMathRevertError.FixedMathBinOpError type.

`@0x/utils`: Have Ganache `Error` -> `RevertError` coercion fail if it can't look up the selector.

packages/utils/CHANGELOG.json

@@ -6,6 +6,10 @@
                 "note": "Allow for array types in `RevertError`s.",
                 "pr": 2075
             },
+            {
+                "note": "Have Ganache `Error` -> `RevertError` coercion fail if it can't look up the selector.",
+                "pr": "TODO"
+            },
             {
                 "note": "Add `LibFixedMath` `RevertError` types.",
                 "pr": "TODO"

packages/utils/src/fixed_math_revert_errors.ts

@@ -35,7 +35,7 @@ export class FixedMathUnsignedValueError extends RevertError {
 
 export class FixedMathBinOpError extends RevertError {
     constructor(error?: BinOpErrorCodes, a?: BigNumber | number | string, b?: BigNumber | number | string) {
-        super('FixedMathBinOpError', 'FixedMathBinOpError(uint8 error, uint256 a, uint256 b)', {
+        super('FixedMathBinOpError', 'FixedMathBinOpError(uint8 error, int256 a, int256 b)', {
             error,
             a,
             b,

packages/utils/src/revert_error.ts

@@ -67,7 +67,7 @@ export function coerceThrownErrorAsRevertError(error: Error): RevertError {
         return decodeThrownErrorAsRevertError(error);
     } catch (err) {
         if (isGanacheTransactionRevertError(error)) {
-            return new AnyRevertError();
+            return err;
         }
         // Handle geth transaction reverts.
         if (isGethTransactionRevertError(error)) {