proceed to learn go!

mytypes/go.mod

@@ -0,0 +1,3 @@
+module mytypes
+
+go 1.24.4

mytypes/mytypes.go

@@ -0,0 +1,35 @@
+package mytypes
+
+import "strings"
+
+type MyInt int
+type MyString string
+type MyBuilder struct {
+	Contents strings.Builder
+}
+
+func (i MyInt) Twice() MyInt {
+	return i * 2
+}
+
+
+func (i MyString) Len() int {
+	return len(i)
+}
+
+func (s MyBuilder) Hello() string {
+	return "Hello, Gophers!"
+}
+
+func (s MyBuilder) Uppers(in string) string {
+	return strings.ToUpper(in)
+}
+
+func Double(input *int) int{
+	*input *= 2
+	return *input
+}
+
+func (input *MyInt) Double() {
+	*input *= 2
+}

mytypes/mytypes_test.go

@@ -0,0 +1,107 @@
+package mytypes_test
+
+import (
+    "mytypes"
+    "testing"
+    "strings"
+)
+
+func TestTwice(t *testing.T) {
+    t.Parallel()
+    input := mytypes.MyInt(9)
+    want := mytypes.MyInt(18)
+    got := input.Twice()
+    if want != got {
+        t.Errorf("twice %d: want %d, got %d", input, want,
+            got)
+    }
+}
+
+func TestMyStringLen(t *testing.T) {
+	t.Parallel()
+	input := mytypes.MyString("lol")
+	want := 3
+	got := input.Len()
+	if want != got {
+		t.Errorf("%q:  want %d, got %d", input, want, got)
+	}
+}
+
+func TestStringsBuilder(t *testing.T) {
+    t.Parallel()
+    var sb strings.Builder
+    sb.WriteString("Hello, ")
+    sb.WriteString("Gophers!")
+    want := "Hello, Gophers!"
+    got := sb.String()
+    if want != got {
+        t.Errorf("want %q, got %q", want, got)
+    }
+    wantLen := 15
+    gotLen := sb.Len()
+    if wantLen != gotLen {
+        t.Errorf("%q: want len %d, got %d", sb.String(),
+            wantLen, gotLen)
+    }
+}
+
+// func TestMyBuilderLen(t *testing.T) {
+//     t.Parallel()
+//     var mb mytypes.MyBuilder
+//     want := 15
+//     got := mb.Len()
+//     if want != got {
+//         t.Errorf("want %d, got %d", want, got)
+//     }
+// }
+
+func TestMyBuilderHello(t *testing.T) {
+    t.Parallel()
+    var mb mytypes.MyBuilder
+    want := "Hello, Gophers!"
+    got := mb.Hello()
+    if want != got {
+        t.Errorf("want %q, got %q", want, got)
+    }
+}
+
+func TestMyBuilder(t *testing.T) {
+    t.Parallel()
+    var mb mytypes.MyBuilder
+    mb.Contents.WriteString("Hello, ")
+    mb.Contents.WriteString("Gophers!")
+    want := "Hello, Gophers!"
+    got := mb.Contents.String()
+    if want != got {
+        t.Errorf("want %q, got %q", want, got)
+    }
+    wantLen := 15
+    gotLen := mb.Contents.Len()
+    if wantLen != gotLen {
+        t.Errorf("%q: want len %d, got %d",
+            mb.Contents.String(), wantLen, gotLen)
+    }
+}
+
+func TestUpperCase(t *testing.T) {
+    t.Parallel()
+    var mb mytypes.MyBuilder
+    input := "hello"
+    want := "HELLO"
+    got := mb.Uppers(input)
+    if got != want {
+        t.Errorf("%q: want %s, got %s",input,want,got)
+    }
+}
+
+func TestDouble(t *testing.T) {
+    t.Parallel()
+    x := mytypes.MyInt(12)
+    want := mytypes.MyInt(24)
+    p := &x
+    p.Double()
+    if want != x {
+        t.Errorf("want %d, got %d",want,x)
+    }
+}
+