refactor: reduce one line of indent in parsing

Checking if the current line is a command can be refactored
into a guard clause.

src/config.rs

@@ -113,6 +113,14 @@ fn parse_contents(contents: String) -> Result<Vec<Hotkey>, Error> {
         ("0", evdev::Key::KEY_0),
     ]);
 
+    let mod_to_mod_enum: HashMap<&str, Modifier> = HashMap::from([
+        ("ctrl", Modifier::Control),
+        ("control", Modifier::Control),
+        ("super", Modifier::Super),
+        ("alt", Modifier::Alt),
+        ("shift", Modifier::Shift),
+    ]);
+
     let lines: Vec<&str> = contents.split('\n').collect();
     let mut hotkeys: Vec<Hotkey> = Vec::new();
 
@@ -135,7 +143,10 @@ fn parse_contents(contents: String) -> Result<Vec<Hotkey>, Error> {
         // in a file are of course counted from 1
         let real_line_no: u32 = (i + 1).try_into().unwrap();
 
-        if key_to_evdev_key.contains_key(lines[i].trim()) {
+        if !key_to_evdev_key.contains_key(lines[i].trim()) {
+            return Err(Error::InvalidConfig(ParseError::UnknownSymbol(real_line_no)));
+        }
+
         // Error if keybind line is at the very last line
         // ( It's impossible for there to be a command )
         if i >= lines.len() - 1 {
@@ -182,9 +193,6 @@ fn parse_contents(contents: String) -> Result<Vec<Hotkey>, Error> {
         // Skip trying to parse the next line (command)
         // because we already dealt with it
         lines_to_skip += 1;
-        } else {
-            return Err(Error::InvalidConfig(ParseError::UnknownSymbol(real_line_no)));
-        }
     }
 
     Ok(hotkeys)
@@ -435,6 +443,7 @@ shift + k +
                                  ParseError::UnknownSymbol(2))
     }
 
+    #[test]
     fn test_common_modifiers() -> std::io::Result<()> {
         let contents = "
 shift + k
@@ -620,7 +629,6 @@ WE WISH YOU A MERRY RUSTMAS
     }
 
     #[test]
-    #[ignore]
     fn test_real_config_snippet() -> std::io::Result<()> {
         let contents = "
 # reloads sxhkd configuration: