feat: add Ellipsis for string

strutil/string.go

@@ -621,6 +621,8 @@ func HammingDistance(a, b string) (int, error) {
 // Concat uses the strings.Builder to concatenate the input strings.
 //   - `length` is the expected length of the concatenated string.
 //   - if you are unsure about the length of the string to be concatenated, please pass 0 or a negative number.
+//
+// Play: todo
 func Concat(length int, str ...string) string {
 	if len(str) == 0 {
 		return ""
@@ -638,3 +640,21 @@ func Concat(length int, str ...string) string {
 	}
 	return sb.String()
 }
+
+// Ellipsis truncates a string to a specified length and appends an ellipsis.
+// Play: todo
+func Ellipsis(str string, length int) string {
+	str = strings.TrimSpace(str)
+
+	if length <= 0 {
+		return ""
+	}
+
+	runes := []rune(str)
+
+	if len(runes) <= length {
+		return str
+	}
+
+	return string(runes[:length]) + "..."
+}

strutil/string_example_test.go

@@ -694,3 +694,18 @@ func ExampleConcat() {
 	// Go Language
 	// An apple a day，keeps the doctor away
 }
+
+func ExampleEllipsis() {
+	result1 := Ellipsis("hello world", 5)
+	result2 := Ellipsis("你好，世界!", 2)
+	result3 := Ellipsis("😀😃😄😁😆", 3)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// hello...
+	// 你好...
+	// 😀😃😄...
+}

strutil/string_test.go

@@ -620,3 +620,27 @@ func TestConcat(t *testing.T) {
 	assert.Equal("你好，世界！", Concat(0, "你好", "，", "", "世界！", ""))
 	assert.Equal("Hello World!", Concat(0, "Hello", " Wo", "r", "ld!", ""))
 }
+
+func TestEllipsis(t *testing.T) {
+	t.Parallel()
+	assert := internal.NewAssert(t, "TestEllipsis")
+
+	tests := []struct {
+		input  string
+		length int
+		want   string
+	}{
+		{"", 0, ""},
+		{"hello world", 0, ""},
+		{"hello world", -1, ""},
+		{"hello world", 5, "hello..."},
+		{"hello world", 11, "hello world"},
+		{"你好，世界!", 2, "你好..."},
+		{"😀😃😄😁😆", 3, "😀😃😄..."},
+		{"This is a test.", 10, "This is a ..."},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(tt.want, Ellipsis(tt.input, tt.length))
+	}
+}