1 files changed, 6 insertions, 10 deletions
diff --git a/test/0x.js.ts b/test/0x.js.ts
index e4e3cc0a7..09266018b 100644
--- a/test/0x.js.ts
+++ b/test/0x.js.ts
@@ -14,15 +14,14 @@ describe('ZeroEx library', () => {
             s: '0x2d887fd3b17bfdce3481f10bea41f45ba9f709d39ce8325427b57afcfc994cee',
         };
         const address = '0x9b2055d370f73ec7d8a03e965129118dc8f5bf83';
-        describe('should return false for malformed signature', () => {
+        describe('should throw if passed a malformed signature', () => {
             it('malformed v', () => {
                 const malformedSignature = {
                     v: 34,
                     r: signature.r,
                     s: signature.s,
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
             it('r lacks 0x prefix', () => {
                 const malformedR = signature.r.replace('0x', '');
@@ -31,18 +30,16 @@ describe('ZeroEx library', () => {
                     r: malformedR,
                     s: signature.s,
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
             it('r is too short', () => {
                 const malformedR = signature.r.substr(10);
                 const malformedSignature = {
                     v: signature.v,
                     r: malformedR,
-                    s: signature.s,
+                    s: signature.s.replace('0', 'z'),
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
             it('s is not hex', () => {
                 const malformedS = signature.s.replace('0', 'z');
@@ -51,8 +48,7 @@ describe('ZeroEx library', () => {
                     r: signature.r,
                     s: malformedS,
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
         });
         it('should return false if the data doesn\'t pertain to the signature & address', () => {