Add testable examples

Also fixed README.md examples that were outdated

README.md

@@ -90,7 +90,7 @@ To assert if Money value is equal to zero use `IsZero()`
 
 ```go
 pound := money.New(100, "GBP")
-result := pound.IsZero(pound) // false
+result := pound.IsZero() // false
 ```
 
 #### Positive value
@@ -99,7 +99,7 @@ To assert if Money value is more than zero use `IsPositive()`
 
 ```go
 pound := money.New(100, "GBP")
-pound.IsPositive(pound) // true
+pound.IsPositive() // true
 ```
 
 #### Negative value
@@ -108,7 +108,7 @@ To assert if Money value is less than zero use `IsNegative()`
 
 ```go
 pound := money.New(100, "GBP")
-pound.IsNegative(pound) // false
+pound.IsNegative() // false
 ```
 
 Operations

money_example_test.go

@@ -0,0 +1,180 @@
+package money_test
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/Rhymond/go-money"
+)
+
+func ExampleMoney() {
+	pound := money.New(100, "GBP")
+	twoPounds, err := pound.Add(pound)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	parties, err := twoPounds.Split(3)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(parties[0].Display())
+	fmt.Println(parties[1].Display())
+	fmt.Println(parties[2].Display())
+
+	// Output:
+	// £0.67
+	// £0.67
+	// £0.66
+}
+
+func ExampleNew() {
+	pound := money.New(100, "GBP")
+
+	fmt.Println(pound.Display())
+
+	// Output:
+	// £1.00
+}
+
+func ExampleMoney_comparisons() {
+	pound := money.New(100, "GBP")
+	twoPounds := money.New(200, "GBP")
+	twoEuros := money.New(200, "EUR")
+
+	gt, err := pound.GreaterThan(twoPounds)
+	fmt.Println(gt, err)
+
+	lt, err := pound.LessThan(twoPounds)
+	fmt.Println(lt, err)
+
+	eq, err := twoPounds.Equals(twoEuros)
+	fmt.Println(eq, err)
+
+	// Output:
+	// false <nil>
+	// true <nil>
+	// false currencies don't match
+}
+
+func ExampleMoney_IsZero() {
+	pound := money.New(100, "GBP")
+	fmt.Println(pound.IsZero())
+
+	// Output:
+	// false
+}
+
+func ExampleMoney_IsPositive() {
+	pound := money.New(100, "GBP")
+	fmt.Println(pound.IsPositive())
+
+	// Output:
+	// true
+}
+
+func ExampleMoney_IsNegative() {
+	pound := money.New(100, "GBP")
+	fmt.Println(pound.IsNegative())
+
+	// Output:
+	// false
+}
+
+func ExampleMoney_Add() {
+	pound := money.New(100, "GBP")
+	twoPounds := money.New(200, "GBP")
+
+	result, err := pound.Add(twoPounds)
+	fmt.Println(result.Display(), err)
+
+	// Output:
+	// £3.00 <nil>
+}
+
+func ExampleMoney_Subtract() {
+	pound := money.New(100, "GBP")
+	twoPounds := money.New(200, "GBP")
+
+	result, err := pound.Subtract(twoPounds)
+	fmt.Println(result.Display(), err)
+
+	// Output:
+	// -£1.00 <nil>
+}
+
+func ExampleMoney_Multiply() {
+	pound := money.New(100, "GBP")
+
+	result := pound.Multiply(2)
+	fmt.Println(result.Display())
+
+	// Output:
+	// £2.00
+}
+
+func ExampleMoney_Absolute() {
+	pound := money.New(-100, "GBP")
+
+	result := pound.Absolute()
+	fmt.Println(result.Display())
+
+	// Output:
+	// £1.00
+}
+
+func ExampleMoney_Split() {
+	pound := money.New(100, "GBP")
+	parties, err := pound.Split(3)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(parties[0].Display())
+	fmt.Println(parties[1].Display())
+	fmt.Println(parties[2].Display())
+
+	// Output:
+	// £0.34
+	// £0.33
+	// £0.33
+}
+
+func ExampleMoney_Allocate() {
+	pound := money.New(100, "GBP")
+	// Allocate is variadic function which can receive ratios as
+	// slice (int[]{33, 33, 33}...) or separated by a comma integers
+	parties, err := pound.Allocate(33, 33, 33)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(parties[0].Display())
+	fmt.Println(parties[1].Display())
+	fmt.Println(parties[2].Display())
+
+	// Output:
+	// £0.34
+	// £0.33
+	// £0.33
+}
+
+func ExampleMoney_Display() {
+	fmt.Println(money.New(123456789, "EUR").Display())
+
+	// Output:
+	// €1,234,567.89
+}
+
+func ExampleMoney_AsMajorUnits() {
+	result := money.New(123456789, "EUR").AsMajorUnits()
+	fmt.Printf("%.2f", result)
+
+	// Output:
+	// 1234567.89
+}