refactor: remove test.rs file and move tests to a module files

src/ansi_escape_code.rs

@@ -2,11 +2,36 @@ pub struct ANSIEscapeCode {
     parameter: String,
 }
 impl ANSIEscapeCode {
-    pub fn new(parameter: String) -> Self {
-        ANSIEscapeCode { parameter }
+    pub fn new(parameter: &str) -> Self {
+        ANSIEscapeCode { parameter: parameter.to_string() }
     }
 
     pub fn code(&self) -> String {
         format!("\\x1b[{}m", self.parameter)
     }
 }
+
+// =======================================================================
+
+#[cfg(test)]
+mod ansi_escape_code_test {
+    use super::*;
+
+    #[test]
+    fn create_simple_ansi_code() {
+        let p = ANSIEscapeCode::new("33");
+        assert_eq!(p.code(), "\\x1b[33m")
+    }
+
+    #[test]
+    fn create_reset_ansi_code() {
+        let reset_ansi = ANSIEscapeCode::new("0");
+        assert_eq!("\\x1b[0m", reset_ansi.code());
+    }
+
+    #[test]
+    fn create_bright_cyan_ansi_code() {
+        let reset_ansi = ANSIEscapeCode::new("96");
+        assert_eq!("\\x1b[96m", reset_ansi.code());
+    }
+}