From 0e7bf6a805f68798577f18cae0e678299b9b1d09 Mon Sep 17 00:00:00 2001
From: Michael Thomson <michael@michaelthomson.dev>
Date: Sat, 25 May 2024 01:55:18 -0400
Subject: [PATCH] structs

---
 structs-methods-interfaces/shapes.go      | 32 +++++++++++++++++++++++
 structs-methods-interfaces/shapes_test.go | 30 +++++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 structs-methods-interfaces/shapes.go
 create mode 100644 structs-methods-interfaces/shapes_test.go

diff --git a/structs-methods-interfaces/shapes.go b/structs-methods-interfaces/shapes.go
new file mode 100644
index 0000000..726816f
--- /dev/null
+++ b/structs-methods-interfaces/shapes.go
@@ -0,0 +1,32 @@
+package structsmethodsinterfaces
+
+import "math"
+
+type Shape interface {
+  Area() float64
+}
+
+type Rectangle struct {
+  Width float64
+  Height float64
+}
+
+func (r Rectangle) Area() float64 {
+  return r.Width * r.Height
+}
+
+type Circle struct {
+  Radius float64
+}
+
+func (c Circle) Area() float64 {
+  return math.Pi * c.Radius * c.Radius
+}
+
+func Perimeter(rectangle Rectangle) float64 {
+  return 2 * (rectangle.Width + rectangle.Height)
+}
+
+func Area(rectangle Rectangle) float64 {
+  return rectangle.Width * rectangle.Height
+}
diff --git a/structs-methods-interfaces/shapes_test.go b/structs-methods-interfaces/shapes_test.go
new file mode 100644
index 0000000..17752ef
--- /dev/null
+++ b/structs-methods-interfaces/shapes_test.go
@@ -0,0 +1,30 @@
+package structsmethodsinterfaces
+
+import "testing"
+
+func TestPerimeter(t *testing.T) {
+  rectangle := Rectangle{10.0, 10.0}
+  got := Perimeter(rectangle)
+  want := 40.0
+
+  if got != want {
+    t.Errorf("got %.2f want %.2f", got, want)
+  }
+}
+
+func TestArea(t *testing.T) {
+  areaTests := []struct {
+    shape Shape
+    want float64
+  }{
+    {Rectangle{12, 6}, 72.0},
+    {Circle{10}, 314.1592653589793},
+  }
+
+  for _, tt := range areaTests {
+    got := tt.shape.Area()
+    if got != tt.want {
+      t.Errorf("got %g want %g", got, tt.want)
+    }
+  }
+}