Add documentation to clarify placeholder detection logic

Co-authored-by: HsiangNianian <44714368+HsiangNianian@users.noreply.github.com>

1 files changed, 12 insertions, 5 deletions

diff --git a/src-tauri/src/main.rs b/src-tauri/src/main.rs
index 3a5f8a5..a24510e 100644
--- a/src-tauri/src/main.rs
+++ b/src-tauri/src/main.rs
@@ -41,16 +41,23 @@ impl MsRefreshTokenState {
 }
 
 /// Check if a string contains unresolved placeholders in the form ${...}
+/// 
+/// After the replacement phase, if a string still contains ${...}, it means
+/// that placeholder variable was not found in the replacements map and is
+/// therefore unresolved. We should skip adding such arguments to avoid
+/// passing malformed arguments to the game launcher.
 fn has_unresolved_placeholder(s: &str) -> bool {
+    // Look for the opening sequence
     if let Some(start_pos) = s.find("${") {
-        // Check if there's a closing brace after the opening
-        if let Some(end_pos) = s[start_pos..].find('}') {
-            // Verify the closing brace is after the opening sequence
-            return end_pos > 2; // "${" is 2 chars, so } must be after position 2
+        // Check if there's a closing brace after the opening sequence
+        if s[start_pos + 2..].find('}').is_some() {
+            // Found a complete ${...} pattern - this is an unresolved placeholder
+            return true;
         }
-        // Found opening but no closing brace - treat as unresolved
+        // Found ${ but no closing } - also treat as unresolved/malformed
         return true;
     }
+    // No ${ found - the string is fully resolved
     false
 }