Added mint and burn tests for zero amounts. (#1230)

test/token/ERC20/BurnableToken.behavior.js

@@ -11,8 +11,15 @@ require('chai')
 function shouldBehaveLikeBurnableToken (owner, initialBalance, [burner]) {
   describe('burn', function () {
     describe('when the given amount is not greater than balance of the sender', function () {
-      const amount = 100;
+      context('for a zero amount', function () {
+        shouldBurn(0);
+      });
 
+      context('for a non-zero amount', function () {
+        shouldBurn(100);
+      });
+
+      function shouldBurn (amount) {
         beforeEach(async function () {
           ({ logs: this.logs } = await this.token.burn(amount, { from: owner }));
         });
@@ -33,6 +40,7 @@ function shouldBehaveLikeBurnableToken (owner, initialBalance, [burner]) {
           event.args.to.should.eq(ZERO_ADDRESS);
           event.args.value.should.be.bignumber.equal(amount);
         });
+      }
     });
 
     describe('when the given amount is greater than the balance of the sender', function () {
@@ -46,10 +54,19 @@ function shouldBehaveLikeBurnableToken (owner, initialBalance, [burner]) {
 
   describe('burnFrom', function () {
     describe('on success', function () {
-      const amount = 100;
+      context('for a zero amount', function () {
+        shouldBurnFrom(0);
+      });
+
+      context('for a non-zero amount', function () {
+        shouldBurnFrom(100);
+      });
+
+      function shouldBurnFrom (amount) {
+        const originalAllowance = amount * 3;
 
         beforeEach(async function () {
-        await this.token.approve(burner, 300, { from: owner });
+          await this.token.approve(burner, originalAllowance, { from: owner });
           const { logs } = await this.token.burnFrom(owner, amount, { from: burner });
           this.logs = logs;
         });
@@ -59,7 +76,7 @@ function shouldBehaveLikeBurnableToken (owner, initialBalance, [burner]) {
         });
 
         it('decrements allowance', async function () {
-        (await this.token.allowance(owner, burner)).should.be.bignumber.equal(200);
+          (await this.token.allowance(owner, burner)).should.be.bignumber.equal(originalAllowance - amount);
         });
 
         it('emits a burn event', async function () {
@@ -74,6 +91,7 @@ function shouldBehaveLikeBurnableToken (owner, initialBalance, [burner]) {
           event.args.to.should.eq(ZERO_ADDRESS);
           event.args.value.should.be.bignumber.equal(amount);
         });
+      }
     });
 
     describe('when the given amount is greater than the balance of the sender', function () {

test/token/ERC20/MintableToken.behavior.js

@@ -93,26 +93,36 @@ function shouldBehaveLikeMintableToken (owner, minter, [anyone]) {
         const from = minter;
 
         describe('when the token minting is not finished', function () {
-          it('mints the requested amount', async function () {
-            await this.token.mint(owner, amount, { from });
+          context('for a zero amount', function () {
+            shouldMint(0);
+          });
 
-            (await this.token.balanceOf(owner)).should.be.bignumber.equal(amount);
+          context('for a non-zero amount', function () {
+            shouldMint(amount);
           });
 
-          it('emits a mint and a transfer event', async function () {
-            const { logs } = await this.token.mint(owner, amount, { from });
+          function shouldMint (amount) {
+            beforeEach(async function () {
+              ({ logs: this.logs } = await this.token.mint(anyone, amount, { from }));
+            });
 
-            const mintEvent = expectEvent.inLogs(logs, 'Mint', {
-              to: owner,
+            it('mints the requested amount', async function () {
+              (await this.token.balanceOf(anyone)).should.be.bignumber.equal(amount);
+            });
+
+            it('emits a mint and a transfer event', async function () {
+              const mintEvent = expectEvent.inLogs(this.logs, 'Mint', {
+                to: anyone,
               });
               mintEvent.args.amount.should.be.bignumber.equal(amount);
 
-            const transferEvent = expectEvent.inLogs(logs, 'Transfer', {
+              const transferEvent = expectEvent.inLogs(this.logs, 'Transfer', {
                 from: ZERO_ADDRESS,
-              to: owner,
+                to: anyone,
               });
               transferEvent.args.value.should.be.bignumber.equal(amount);
             });
+          }
         });
 
         describe('when the token minting is finished', function () {
@@ -121,7 +131,7 @@ function shouldBehaveLikeMintableToken (owner, minter, [anyone]) {
           });
 
           it('reverts', async function () {
-            await assertRevert(this.token.mint(owner, amount, { from }));
+            await assertRevert(this.token.mint(anyone, amount, { from }));
           });
         });
       });
@@ -131,7 +141,7 @@ function shouldBehaveLikeMintableToken (owner, minter, [anyone]) {
 
         describe('when the token minting is not finished', function () {
           it('reverts', async function () {
-            await assertRevert(this.token.mint(owner, amount, { from }));
+            await assertRevert(this.token.mint(anyone, amount, { from }));
           });
         });
 
@@ -141,7 +151,7 @@ function shouldBehaveLikeMintableToken (owner, minter, [anyone]) {
           });
 
           it('reverts', async function () {
-            await assertRevert(this.token.mint(owner, amount, { from }));
+            await assertRevert(this.token.mint(anyone, amount, { from }));
           });
         });
       });