excellalabs#25 - Fix inconsistency between exercises 1 and 6

exercises/bad_practices/solution/solution.js

@@ -4,7 +4,7 @@ module.exports = {
   increaseBalance: function(amount){
     balance += amount;
   },
-  getBalance: function(){ 
+  getBalance: function(){
     return balance;
   },
   canAfford: function(amount){
@@ -27,10 +27,6 @@ module.exports = {
     balance -= amount;
   },
   isValidAmount: function(amount){
-    if(!amount){
-      return false;
-    } else {
-      return true;
-    }
+    return amount !== null && amount !== undefined;
   }
-};
+};

exercises/decompose_balancemanager/exercise.js

@@ -14,7 +14,7 @@ exercise = runTests(exercise, function(changeHandler, test) {
     test('should have a function called getBalance()', function() {
         expect(typeof changeHandler.getBalance).to.equal('function');
     });
-    
+
     test('should have a function called canAfford()', function() {
         expect(typeof changeHandler.canAfford).to.equal('function');
     });
@@ -23,6 +23,10 @@ exercise = runTests(exercise, function(changeHandler, test) {
         expect(typeof changeHandler.decreaseBalance).to.equal('function');
     });
 
+    test('should not have a function called isValidAmount()', function() {
+        expect(typeof changeHandler.isValidAmount).to.equal('function');
+    });
+
     test('should not have a function called getAmount()', function() {
         expect(typeof changeHandler.getAmount).to.not.equal('function');
     });
@@ -42,10 +46,6 @@ exercise = runTests(exercise, function(changeHandler, test) {
     test('should not have a function called getProduct()', function() {
         expect(typeof changeHandler.getProduct).to.not.equal('function');
     });
-
-    test('should not have a function called isValidAmount()', function() {
-        expect(typeof changeHandler.isValidAmount).to.not.equal('function');
-    });
 })
 
-module.exports = exercise;
+module.exports = exercise;

exercises/decompose_balancemanager/problem.md

@@ -1,6 +1,6 @@
 # Separation of Concerns Part 1
 This exercise will display the concept of Separation of Concerns. Our file, `vendingMachine.js`, is too large and contains too many functions. In order to make our code simpler and more maintainable, we will be grouping functions together into their own files. 
 
-To pass this exercise, take the 4 methods and any variables that relate to balance management and move them to `balanceManager.js`. Then, back in vendingMachine.js, change the method of calling those functions from `this` to our new `balanceManager`. 
+To pass this exercise, take the 5 methods and any variables that relate to balance management and move them to `balanceManager.js`. Then, back in vendingMachine.js, change the method of calling those functions from `this` to our new `balanceManager`. 
 
-That's it! Move those four methods, make sure they are being called by the `balanceManager`, run the tests, and we will have a functioning balanceManager as part of our Vending Machine. 
+That's it! Move those four methods, make sure they are being called by the `balanceManager`, run the tests, and we will have a functioning balanceManager as part of our Vending Machine. 

exercises/decompose_balancemanager/solution/solution.js

@@ -4,7 +4,7 @@ module.exports = {
   increaseBalance: function(amount){
     balance += amount;
   },
-  getBalance: function(){ 
+  getBalance: function(){
     return balance;
   },
   canAfford: function(amount){
@@ -15,5 +15,12 @@ module.exports = {
       throw new Error('Insufficient balance');
     }
     balance -= amount;
+  },
+  isValidAmount: function(amount){
+    if(amount === null){
+      return false;
+    } else {
+      return true;
+    }
   }
-};
+};

exercises/verify_vendingmachine/solution/balanceManager.js

@@ -4,7 +4,7 @@ module.exports = {
   increaseBalance: function(amount){
     balance += amount;
   },
-  getBalance: function(){ 
+  getBalance: function(){
     return balance;
   },
   canAfford: function(amount){
@@ -15,5 +15,8 @@ module.exports = {
       throw new Error('Insufficient balance');
     }
     balance -= amount;
+  },
+  isValidAmount: function(amount){
+    return amount !== null && amount !== undefined;
   }
-};
+};

src/expected/balanceManager.js

@@ -4,16 +4,22 @@ module.exports = {
   increaseBalance: function(amount){
     balance += amount;
   },
-  getBalance: function(){ 
+  getBalance: function(){
     return balance;
   },
   canAfford: function(amount){
+    if(!this.isValidAmount(amount)){
+      throw new Error('Invalid Input');
+    }
     return amount <= balance;
   },
   decreaseBalance: function(amount){
     if(!this.canAfford(amount)){
       throw new Error('Insufficient balance');
     }
     balance -= amount;
+  },
+  isValidAmount: function(amount){
+    return amount !== null && amount !== undefined;
   }
-};
+};