sql+SQLStudio: Recover from errors preparing SQL statements

In both applications, display the SQL statement that failed to parse.
For the REPL, ensure the REPL prompts the user for another statement.
For SQLStudio, we don't continue executing the script as it likely does
not make sense to run statements that come after a failed statement.

Userland/DevTools/SQLStudio/MainWidget.cpp

@@ -440,7 +440,7 @@ void MainWidget::drop_event(GUI::DropEvent& drop_event)
     }
 }
 
-DeprecatedString MainWidget::read_next_sql_statement_of_editor()
+void MainWidget::read_next_sql_statement_of_editor()
 {
     StringBuilder piece;
     do {
@@ -450,7 +450,7 @@ DeprecatedString MainWidget::read_next_sql_statement_of_editor()
         auto line_maybe = read_next_line_of_editor();
 
         if (!line_maybe.has_value())
-            return {};
+            return;
 
         auto& line = line_maybe.value();
         auto lexer = SQL::AST::Lexer(line);
@@ -490,10 +490,16 @@ DeprecatedString MainWidget::read_next_sql_statement_of_editor()
             m_editor_line_level = last_token_ended_statement ? 0 : (m_editor_line_level > 0 ? m_editor_line_level : 1);
     } while ((m_editor_line_level > 0) || piece.is_empty());
 
-    if (auto statement_id = m_sql_client->prepare_statement(m_connection_id, piece.to_deprecated_string()); statement_id.has_value())
+    auto sql_statement = piece.to_deprecated_string();
+
+    if (auto statement_id = m_sql_client->prepare_statement(m_connection_id, sql_statement); statement_id.has_value()) {
         m_sql_client->async_execute_statement(*statement_id, {});
+    } else {
+        auto* editor = dynamic_cast<ScriptEditor*>(m_tab_widget->active_widget());
+        VERIFY(editor);
 
-    return piece.to_deprecated_string();
+        GUI::MessageBox::show_error(window(), DeprecatedString::formatted("Could not parse {}\n{}", editor->path(), sql_statement));
+    }
 }
 
 Optional<DeprecatedString> MainWidget::read_next_line_of_editor()

Userland/DevTools/SQLStudio/MainWidget.h

@@ -61,7 +61,7 @@ private:
     RefPtr<SQL::SQLClient> m_sql_client;
     Vector<Vector<DeprecatedString>> m_results;
 
-    DeprecatedString read_next_sql_statement_of_editor();
+    void read_next_sql_statement_of_editor();
     Optional<DeprecatedString> read_next_line_of_editor();
     size_t m_current_line_for_parsing { 0 };
     int m_editor_line_level { 0 };

Userland/DevTools/SQLStudio/ScriptEditor.h

@@ -24,6 +24,8 @@ public:
     ErrorOr<bool> save_as();
     ErrorOr<bool> attempt_to_close();
 
+    DeprecatedString const& path() const { return m_path; }
+
 private:
     ScriptEditor();
 

Userland/Utilities/sql.cpp

@@ -275,6 +275,11 @@ private:
                 });
         } else if (auto statement_id = m_sql_client->prepare_statement(m_connection_id, piece); statement_id.has_value()) {
             m_sql_client->async_execute_statement(*statement_id, {});
+        } else {
+            warnln("\033[33;1mError parsing SQL statement\033[0m: {}", piece);
+            m_loop.deferred_invoke([this]() {
+                read_sql();
+            });
         }
 
         // ...But m_keep_running can also be set to false by a command handler.