style: cleanup run_length_encoding.rs (#744)

* style: include `string_to_string`

* style: reduce code duplication

* style: empty input is a regular input

Author: vil02

Cargo.toml

@@ -140,7 +140,6 @@ std_instead_of_core = { level = "allow", priority = 1 }
 str_to_string = { level = "allow", priority = 1 }
 string_add = { level = "allow", priority = 1 }
 string_slice = { level = "allow", priority = 1 }
-string_to_string = { level = "allow", priority = 1 }
 undocumented_unsafe_blocks = { level = "allow", priority = 1 }
 unnecessary_safety_comment = { level = "allow", priority = 1 }
 unneeded_field_pattern = { level = "allow", priority = 1 }

src/string/run_length_encoding.rs

@@ -1,6 +1,6 @@
 pub fn run_length_encoding(target: &str) -> String {
     if target.trim().is_empty() {
-        return "String is Empty!".to_string();
+        return "".to_string();
     }
     let mut count: i32 = 0;
     let mut base_character: String = "".to_string();
@@ -27,9 +27,8 @@ pub fn run_length_encoding(target: &str) -> String {
 
 pub fn run_length_decoding(target: &str) -> String {
     if target.trim().is_empty() {
-        return "String is Empty!".to_string();
+        return "".to_string();
     }
-
     let mut character_count: String = String::new();
     let mut decoded_target = String::new();
 
@@ -55,61 +54,25 @@ pub fn run_length_decoding(target: &str) -> String {
 mod tests {
     use super::*;
 
-    #[test]
-    fn encode_empty() {
-        assert_eq!(run_length_encoding(""), "String is Empty!")
-    }
-
-    #[test]
-    fn encode_identical_character() {
-        assert_eq!(run_length_encoding("aaaaaaaaaa"), "10a")
-    }
-    #[test]
-    fn encode_continuous_character() {
-        assert_eq!(run_length_encoding("abcdefghijk"), "1a1b1c1d1e1f1g1h1i1j1k")
-    }
-
-    #[test]
-    fn encode_random_character() {
-        assert_eq!(run_length_encoding("aaaaabbbcccccdddddddddd"), "5a3b5c10d")
-    }
-
-    #[test]
-    fn encode_long_character() {
-        assert_eq!(
-            run_length_encoding(
-                "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbcccccdddddddddd"
-            ),
-            "200a3b5c10d"
-        )
-    }
-    #[test]
-    fn decode_empty() {
-        assert_eq!(run_length_decoding(""), "String is Empty!")
-    }
-
-    #[test]
-    fn decode_identical_character() {
-        assert_eq!(run_length_decoding("10a"), "aaaaaaaaaa")
-    }
-    #[test]
-    fn decode_continuous_character() {
-        assert_eq!(run_length_decoding("1a1b1c1d1e1f1g1h1i1j1k"), "abcdefghijk")
-    }
-
-    #[test]
-    fn decode_random_character() {
-        assert_eq!(
-            run_length_decoding("5a3b5c10d").to_string(),
-            "aaaaabbbcccccdddddddddd"
-        )
+    macro_rules! test_run_length {
+        ($($name:ident: $test_case:expr,)*) => {
+            $(
+                #[test]
+                fn $name() {
+                    let (raw_str, encoded) = $test_case;
+                    assert_eq!(run_length_encoding(raw_str), encoded);
+                    assert_eq!(run_length_decoding(encoded), raw_str);
+                }
+            )*
+        };
     }
 
-    #[test]
-    fn decode_long_character() {
-        assert_eq!(
-            run_length_decoding("200a3b5c10d"),
-            "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbcccccdddddddddd"
-        )
+    test_run_length! {
+        empty_input: ("", ""),
+        repeated_char: ("aaaaaaaaaa", "10a"),
+        no_repeated: ("abcdefghijk", "1a1b1c1d1e1f1g1h1i1j1k"),
+        regular_input: ("aaaaabbbcccccdddddddddd", "5a3b5c10d"),
+        two_blocks_with_same_char: ("aaabbaaaa", "3a2b4a"),
+        long_input: ("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbcccccdddddddddd", "200a3b5c10d"),
     }
 }