Fix bug where prior LSP completions can be displayed after trigger char (#32927)

Bug in #31872

Closes #32774

Release Notes:

- Fixed a bug in LSP completions caching where prior completions may be
used when they should not, after typing a trigger char like `.`

crates/editor/src/editor.rs

@@ -5266,6 +5266,37 @@ impl Editor {
             .as_ref()
             .map_or(true, |provider| provider.filter_completions());
 
+        let trigger_kind = match trigger {
+            Some(trigger) if buffer.read(cx).completion_triggers().contains(trigger) => {
+                CompletionTriggerKind::TRIGGER_CHARACTER
+            }
+            _ => CompletionTriggerKind::INVOKED,
+        };
+        let completion_context = CompletionContext {
+            trigger_character: trigger.and_then(|trigger| {
+                if trigger_kind == CompletionTriggerKind::TRIGGER_CHARACTER {
+                    Some(String::from(trigger))
+                } else {
+                    None
+                }
+            }),
+            trigger_kind,
+        };
+
+        // Hide the current completions menu when a trigger char is typed. Without this, cached
+        // completions from before the trigger char may be reused (#32774). Snippet choices could
+        // involve trigger chars, so this is skipped in that case.
+        if trigger_kind == CompletionTriggerKind::TRIGGER_CHARACTER && self.snippet_stack.is_empty()
+        {
+            let menu_is_open = matches!(
+                self.context_menu.borrow().as_ref(),
+                Some(CodeContextMenu::Completions(_))
+            );
+            if menu_is_open {
+                self.hide_context_menu(window, cx);
+            }
+        }
+
         if let Some(CodeContextMenu::Completions(menu)) = self.context_menu.borrow_mut().as_mut() {
             if filter_completions {
                 menu.filter(query.clone(), provider.clone(), window, cx);
@@ -5296,23 +5327,6 @@ impl Editor {
             }
         };
 
-        let trigger_kind = match trigger {
-            Some(trigger) if buffer.read(cx).completion_triggers().contains(trigger) => {
-                CompletionTriggerKind::TRIGGER_CHARACTER
-            }
-            _ => CompletionTriggerKind::INVOKED,
-        };
-        let completion_context = CompletionContext {
-            trigger_character: trigger.and_then(|trigger| {
-                if trigger_kind == CompletionTriggerKind::TRIGGER_CHARACTER {
-                    Some(String::from(trigger))
-                } else {
-                    None
-                }
-            }),
-            trigger_kind,
-        };
-
         let (word_replace_range, word_to_exclude) = if let (word_range, Some(CharKind::Word)) =
             buffer_snapshot.surrounding_word(buffer_position)
         {