feat: handle errors in extract_alias function with enum

src/syntax_tree/alias.rs

@@ -1,31 +1,57 @@
+// Unquote a string (remove the quotes if it has)
+// 'foo' -> foo
+// "foo" -> foo
+// foo -> foo
+// "\'foo\'" -> 'foo'
+// TODO: Add tests
+fn unquote_string(string: &str) -> String {
+    let has_single_quotes = string.starts_with('\'') && string.ends_with('\'');
+    let has_double_quotes = string.starts_with('"') && string.ends_with('"');
+
+    if has_single_quotes || has_double_quotes {
+        string[1..string.len() - 1].to_string()
+    } else {
+        string.to_string()
+    }
+}
+
+enum AliasError {
+    MissingCommandName,
+    MissingAliasName,
+    MissingArguments,
+    InvalidArgumentCount,
+    InvalidUtf8Text,
+}
+
+// https://www.gnu.org/software/bash/manual/html_node/Quoting.html
 // TODO: Handle each error of this function with a enum (AliasError)
 // return: -> Result<(String, String), AliasError> {
 fn extract_alias(
     node: tree_sitter::Node,
     source: &[u8],
-) -> Option<(String, String)> {
+) -> Result<(String, String), AliasError> {
     let mut cursor = node.walk();
 
     // Find the command_name node
     if !cursor.goto_first_child() || cursor.node().kind() != "command_name" {
-        return None;
+        return Err(AliasError::MissingCommandName);
     }
 
     // Check if it's an alias command
     let command_name = cursor.node().utf8_text(source).unwrap();
     if command_name != "alias" {
-        return None;
+        return Err(AliasError::MissingAliasName);
     }
 
     // Go to the argument node
     if !cursor.goto_next_sibling() {
-        return None;
+        return Err(AliasError::MissingArguments);
     }
 
     let node = cursor.node();
 
     if node.child_count() != 2 {
-        return None;
+        return Err(AliasError::InvalidArgumentCount);
     }
 
     cursor.goto_first_child();
@@ -38,16 +64,14 @@ fn extract_alias(
 
     cursor.goto_next_sibling();
 
-    let alias_content_node = cursor.node();
-    let alias_content = alias_content_node
-        .utf8_text(source)
-        .unwrap()
-        // TODO: Check all the cases for quotting in the Bash reference manual:
-        // https://www.gnu.org/software/bash/manual/html_node/Quoting.html
-        // and implement a unquote content fn
-        .trim_matches('\'');
+    let alias_content = match cursor.node().utf8_text(source) {
+        Ok(alias_content) => alias_content,
+        Err(_) => return Err(AliasError::InvalidUtf8Text),
+    };
+
+    let unquoted_alias_content = unquote_string(alias_content);
 
-    Some((alias_name.to_string(), alias_content.to_string()))
+    Ok((alias_name.to_string(), unquoted_alias_content))
 }
 
 pub fn find_aliases(
@@ -65,7 +89,7 @@ pub fn find_aliases(
         let node = cursor.node();
 
         if node.kind() == "command" {
-            if let Some(alias) = extract_alias(node, source) {
+            if let Ok(alias) = extract_alias(node, source) {
                 aliases.push(alias);
             }
         } // TODO: Implement alias detection inside functions