1 files changed, 54 insertions, 14 deletions
diff --git a/src/main.rs b/src/main.rs
index 0c994ef..2518e02 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,7 +23,7 @@ const EXCEPTIONS: &[&str] = &[
 fn main() {
     let mut args = args();
     args.next(); // ignore self arg
-    let mut ignorables = Vec::new();
+    let mut ignorables = HashSet::new();
 
     while let Some(arg) = args.next() {
         match arg.as_str() {
@@ -33,6 +33,7 @@ fn main() {
             }
             "--help" | "-h" => {
                 println!("{}", HELP_MSG);
+                return;
             }
             unrecognized => {
                 panic!(format!("Unrecognized option: {}", unrecognized));
@@ -51,7 +52,11 @@ fn main() {
 }
 
 /// Corrects a single line (title) based on placement and exceptions.
-fn correct_line(line: &str, ignorables: &[String], exceptions: &HashSet<&'static str>) -> String {
+fn correct_line(
+    line: &str,
+    ignorables: &HashSet<String>,
+    exceptions: &HashSet<&'static str>,
+) -> String {
     let mut line = line.split_whitespace().peekable();
     let mut result = String::new();
 
@@ -81,7 +86,7 @@ fn correct_line(line: &str, ignorables: &[String], exceptions: &HashSet<&'static
 fn correct_word(
     word: &str,
     first_or_last: bool,
-    ignorables: &[String],
+    ignorables: &HashSet<String>,
     exceptions: &HashSet<&'static str>,
 ) -> String {
     if ignorables.iter().any(|s| s == word) {
@@ -99,8 +104,14 @@ fn correct_word(
 /// Capitalizes the first letter of a single word.
 fn capitalize_word(word: &str) -> String {
     let mut chars = word.chars();
-    let first = chars.next().unwrap_or_default();
-    first.to_uppercase().chain(chars).collect()
+
+    if let Some(first) = chars.next() {
+        // uppercase first character and append the rest
+        first.to_uppercase().chain(chars).collect()
+    } else {
+        // handle empty words
+        String::new()
+    }
 }
 
 #[cfg(test)]
@@ -116,23 +127,43 @@ mod tests {
     #[test]
     fn test_correct_word() {
         assert_eq!(
-            correct_word("Like", false, &[], &EXCEPTIONS.iter().cloned().collect()),
+            correct_word(
+                "Like",
+                false,
+                &HashSet::new(),
+                &EXCEPTIONS.iter().cloned().collect()
+            ),
             String::from("like")
         );
         assert_eq!(
-            correct_word("like", false, &[], &EXCEPTIONS.iter().cloned().collect()),
+            correct_word(
+                "like",
+                false,
+                &HashSet::new(),
+                &EXCEPTIONS.iter().cloned().collect()
+            ),
             String::from("like")
         );
         assert_eq!(
-            correct_word("like", true, &[], &EXCEPTIONS.iter().cloned().collect()),
+            correct_word(
+                "like",
+                true,
+                &HashSet::new(),
+                &EXCEPTIONS.iter().cloned().collect()
+            ),
             String::from("Like")
         );
         assert_eq!(
-            correct_word("liKe", false, &[], &EXCEPTIONS.iter().cloned().collect()),
+            correct_word(
+                "liKe",
+                false,
+                &HashSet::new(),
+                &EXCEPTIONS.iter().cloned().collect()
+            ),
             String::from("like")
         );
         assert_eq!(
-            correct_word("computers", false, &[], &HashSet::new()),
+            correct_word("computers", false, &HashSet::new(), &HashSet::new()),
             String::from("Computers")
         );
     }
@@ -140,13 +171,17 @@ mod tests {
     #[test]
     fn test_correct_line() {
         assert_eq!(
-            correct_line("this is a test", &[], &EXCEPTIONS.iter().cloned().collect()),
+            correct_line(
+                "this is a test",
+                &HashSet::new(),
+                &EXCEPTIONS.iter().cloned().collect()
+            ),
             String::from("This Is a Test")
         );
         assert_eq!(
             correct_line(
                 "similEs: lIke Or As",
-                &[],
+                &HashSet::new(),
                 &EXCEPTIONS.iter().cloned().collect()
             ),
             String::from("Similes: like or As")
@@ -155,14 +190,19 @@ mod tests {
 
     #[test]
     fn test_proper_nouns_acronyms() {
+        let mut ignorables = HashSet::new();
+        ignorables.insert(String::from("FreeBSD"));
         assert_eq!(
-            correct_line("FreeBSD", &[String::from("FreeBSD")], &HashSet::new()),
+            correct_line("FreeBSD", &ignorables, &HashSet::new()),
             String::from("FreeBSD")
         );
     }
 
     #[test]
     fn test_empty_lines() {
-        assert_eq!(correct_line("", &[], &HashSet::new()), String::from(""),);
+        assert_eq!(
+            correct_line("", &HashSet::new(), &HashSet::new()),
+            String::from(""),
+        );
     }
 }