a little refactoring and now pointers are live

pointers/readme.md

@@ -1,4 +1,4 @@
-# Pointers and errors (WIP)
+# Pointers and errors
 
 We learned about structs in the last section which let us capture a number of values related around a concept. 
 
@@ -343,20 +343,21 @@ Let's try this out in a test
 
 ```go
 t.Run("Withdraw insufficient funds", func(t *testing.T) {
-    wallet := Wallet{Bitcoin(20)}
+    startingBalance := Bitcoin(20)
+    wallet := Wallet{startingBalance}
     err := wallet.Withdraw(Bitcoin(100))
 
-    assertBalance(t, wallet, Bitcoin(20))
+    assertBalance(t, wallet, startingBalance)
 
     if err == nil {
         t.Error("wanted an error but didn't get one")
     }
 })
 ```
 
-We want `Withdraw` to return an error _if_ you try and take out more than you have.
+We want `Withdraw` to return an error _if_ you try and take out more than you have and the balance should stay the same
 
-We then check it has returned it by failing the test if it is `nil`
+We then check an error has returned by failing the test if it is `nil`.
 
 `nil` is synonymous with `null` from other programming languages. Errors can be `nil` because the return type of `Widthdraw` will be `error`, which is an interface. If you see a function that takes arguments or returns values that are interfaces, they can be nillable. 
 
@@ -445,10 +446,11 @@ And then update the caller
 
 ```go
 t.Run("Withdraw insufficient funds", func(t *testing.T) {
-    wallet := Wallet{Bitcoin(20)}
+    startingBalance := Bitcoin(20)
+    wallet := Wallet{startingBalance}
     err := wallet.Withdraw(Bitcoin(100))
 
-    assertBalance(t, wallet, Bitcoin(20))
+    assertBalance(t, wallet, startingBalance)
     assertError(t, err, "cannot withdraw, insufficient funds")
 })
 ```

pointers/v3/wallet_test.go

@@ -35,10 +35,11 @@ func TestWallet(t *testing.T) {
 	})
 
 	t.Run("Withdraw insufficient funds", func(t *testing.T) {
-		wallet := Wallet{Bitcoin(20)}
+		startingBalance := Bitcoin(20)
+		wallet := Wallet{startingBalance}
 		err := wallet.Withdraw(Bitcoin(100))
 
-		assertBalance(t, wallet, Bitcoin(20))
+		assertBalance(t, wallet, startingBalance)
 		assertError(t, err)
 	})
 }

pointers/v4/wallet_test.go

@@ -22,10 +22,11 @@ func TestWallet(t *testing.T) {
 	})
 
 	t.Run("Withdraw insufficient funds", func(t *testing.T) {
-		wallet := Wallet{Bitcoin(20)}
+		startingBalance := Bitcoin(20)
+		wallet := Wallet{startingBalance}
 		err := wallet.Withdraw(Bitcoin(100))
 
-		assertBalance(t, wallet, Bitcoin(20))
+		assertBalance(t, wallet, startingBalance)
 		assertError(t, err, InsufficientFundsError)
 	})
 }

readme.md

@@ -22,7 +22,7 @@ If there's no link, it's not done yet! [why not contribute?](contributing.md)
 3. [Iteration](/for) - Learn about `for` and benchmarking.
 4. [Arrays and slices](/arrays) - Learn about arrays, slices, `len`, varargs, `range` and test coverage.
 5. [Structs, methods & interfaces](/structs) - Learn about `struct`, methods, `interface` and table driven tests.
-6. [Pointers & errors (WIP)](/pointers) - Learn about pointers, errors and type aliasing.
+6. [Pointers & errors](/pointers) - Learn about pointers, errors and type aliasing.
 7. [Dependency Injection & interfaces (WIP)](/di-and-interfaces) - Learn about dependency injection, how it relates to using interfaces and a primer on io
 8. Concurrency (WIP)
 9. Errors