testing

hello/hello.go

@@ -1,7 +1,11 @@
 package main
 
-import "fmt"
+import (
+        "fmt"
+        "c.infdj.com/GO/courses_golang/hello/morestrings"
+)
 
 func main() {
-	fmt.Println("Hello, world.")
+        // fmt.Println("Hello, world.")
+        fmt.Println(morestrings.ReverseRunes("!oG ,olleH"))
 }

hello/morestrings/reverse.go

@@ -0,0 +1,12 @@
+// Package morestrings implements additional functions to manipulate UTF-8
+// encoded strings, beyond what is provided in the standard "strings" package.
+package morestrings
+
+// ReverseRunes returns its argument string reversed rune-wise left to right.
+func ReverseRunes(s string) string {
+	r := []rune(s)
+	for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 {
+		r[i], r[j] = r[j], r[i]
+	}
+	return string(r)
+}

hello/morestrings/reverse_test.go

@@ -0,0 +1,19 @@
+package morestrings
+
+import "testing"
+
+func TestReverseRunes(t *testing.T) {
+	cases := []struct {
+		in, want string
+	}{
+		{"Hello, world", "dlrow ,olleH"},
+		{"Hello, 世界", "界世 ,olleH"},
+		{"", ""},
+	}
+	for _, c := range cases {
+		got := ReverseRunes(c.in)
+		if got != c.want {
+			t.Errorf("ReverseRunes(%q) == %q, want %q", c.in, got, c.want)
+		}
+	}
+}