Ownable behavior (#929)

* added function to renounce ownership

* Provide an Ownable behavior for testing (#905)

* Fix indentation

* Convert to use should assertions

test/ownership/Ownable.behaviour.js

+import EVMRevert from '../helpers/EVMRevert';
+
+const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
+
+require('chai')
+  .use(require('chai-as-promised'))
+  .should();
+
+export default function (accounts) {
+  describe('as an ownable', function () {
+    it('should have an owner', async function () {
+      let owner = await this.ownable.owner();
+      owner.should.not.eq(ZERO_ADDRESS);
+    });
+
+    it('changes owner after transfer', async function () {
+      let other = accounts[1];
+      await this.ownable.transferOwnership(other);
+      let owner = await this.ownable.owner();
+
+      owner.should.eq(other);
+    });
+
+    it('should prevent non-owners from transfering', async function () {
+      const other = accounts[2];
+      const owner = await this.ownable.owner.call();
+      owner.should.not.eq(other);
+      await this.ownable.transferOwnership(other, { from: other }).should.be.rejectedWith(EVMRevert);
+    });
+
+    it('should guard ownership against stuck state', async function () {
+      let originalOwner = await this.ownable.owner();
+      await this.ownable.transferOwnership(null, { from: originalOwner }).should.be.rejectedWith(EVMRevert);
+    });
+
+    it('loses owner after renouncement', async function () {
+      await this.ownable.renounceOwnership();
+      let owner = await this.ownable.owner();
+
+      owner.should.eq(ZERO_ADDRESS);
+    });
+
+    it('should prevent non-owners from renouncement', async function () {
+      const other = accounts[2];
+      const owner = await this.ownable.owner.call();
+      owner.should.not.eq(other);
+      await this.ownable.renounceOwnership({ from: other }).should.be.rejectedWith(EVMRevert);
+    });
+  });
+};

test/ownership/Ownable.test.js

+import shouldBehaveLikeOwnable from './Ownable.behaviour';
 
-import assertRevert from '../helpers/assertRevert';
-
-var Ownable = artifacts.require('Ownable');
-const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000';
+const Ownable = artifacts.require('Ownable');
 
 contract('Ownable', function (accounts) {
-  let ownable;
-
   beforeEach(async function () {
-    ownable = await Ownable.new();
-  });
-
-  it('should have an owner', async function () {
-    let owner = await ownable.owner();
-    assert.isTrue(owner !== 0);
+    this.ownable = await Ownable.new();
   });
 
-  it('changes owner after transfer', async function () {
-    let other = accounts[1];
-    await ownable.transferOwnership(other);
-    let owner = await ownable.owner();
-
-    assert.isTrue(owner === other);
-  });
-
-  it('should prevent non-owners from transfering', async function () {
-    const other = accounts[2];
-    const owner = await ownable.owner.call();
-    assert.isTrue(owner !== other);
-    await assertRevert(ownable.transferOwnership(other, { from: other }));
-  });
-
-  it('should guard ownership against stuck state', async function () {
-    let originalOwner = await ownable.owner();
-    await assertRevert(ownable.transferOwnership(null, { from: originalOwner }));
-  });
-
-  it('loses owner after renouncement', async function () {
-    await ownable.renounceOwnership();
-    let owner = await ownable.owner();
-
-    assert.isTrue(owner === ZERO_ADDRESS);
-  });
-
-  it('should prevent non-owners from renouncement', async function () {
-    const other = accounts[2];
-    const owner = await ownable.owner.call();
-    assert.isTrue(owner !== other);
-    await assertRevert(ownable.renounceOwnership({ from: other }));
-  });
+  shouldBehaveLikeOwnable(accounts);
 });