refactor(strung): unique strings (#16)

Author: scholar7r

strung/strung.go

@@ -3,13 +3,7 @@ package strung
 
 import "strings"
 
-// TrimAround trims characters around string
-//
-// Example:
-//
-// ```go
-// v := TrimAround([]string{" ADD ", " 1 ", " AND ", " 2 "}) // v = []string{"ADD", "1", "AND", "2"}
-// ```.
+// TrimAround trims characters around string.
 func TrimAround(v []string, cutset string) []string {
 	var trimmed []string
 
@@ -19,3 +13,20 @@ func TrimAround(v []string, cutset string) []string {
 
 	return trimmed
 }
+
+// Unique removes duplicated strings from a slice, preserving order.
+func Unique(slice []string) []string {
+	var (
+		seen   = make(map[string]struct{}, len(slice))
+		result = make([]string, 0, len(slice))
+	)
+
+	for _, v := range slice {
+		if _, exists := seen[v]; !exists {
+			seen[v] = struct{}{}
+			result = append(result, v)
+		}
+	}
+
+	return result
+}

strung/strung_test.go

@@ -36,3 +36,25 @@ func TestTrimAround(t *testing.T) {
 		})
 	}
 }
+
+func TestUnique(t *testing.T) {
+	tests := []struct {
+		name  string
+		slice []string
+		want  []string
+	}{
+		{
+			name:  "unique strings",
+			slice: []string{"a", "b", "a", "c"},
+			want:  []string{"a", "b", "c"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := strung.Unique(tt.slice)
+			if slices.Compare(got, tt.want) != 0 {
+				t.Errorf("Unique() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}