ux(sql-workspace): readable query errors: driver message first, details folded and unwrapped, Copy (#1557)

lib/core/database/query_error_text.dart

@@ -0,0 +1,72 @@
+/// A failed query as the results pane shows it (#1557): one readable line,
+/// and the driver's text without the statement the app wrapped around the
+/// user's SQL.
+class QueryErrorText {
+  const QueryErrorText({required this.summary, required this.detail});
+
+  /// Reads [raw], the `toString()` of whatever the driver threw.
+  factory QueryErrorText.parse(String raw) {
+    final detail = _unwrap(raw.trim());
+    return QueryErrorText(summary: _summary(detail), detail: detail);
+  }
+
+  /// The driver's message alone: `no such column: u.name`.
+  final String summary;
+
+  /// The whole driver text, minus the app's own wrapping.
+  final String detail;
+
+  /// Whether [detail] says more than [summary].
+  bool get hasDetail => detail != summary;
+
+  static const _maxSummary = 300;
+
+  // SQLite (sqlite3): `SqliteException(1): while preparing statement, <msg>,
+  // SQL logic error (code 1)`.
+  static final _sqlite = RegExp(
+    r'SqliteException\(\d+\): (?:while [^,\n]+, )?([^\n]+?)'
+    r'(?:, [^,\n]*\(code \d+\))?(?:\n|$)',
+  );
+
+  // PostgreSQL (postgres 3): `Severity.error 42703: column "x" does not exist
+  // detail: ... hint: ...`.
+  static final _postgres = RegExp(
+    r'\b(?:Severity\.)?(?:error|fatal|panic|ERROR|FATAL|PANIC) '
+    r'[0-9A-Z]{5}: ([^\n]+?)(?= (?:detail|hint|table|column|constraint)\b|\n|$)',
+  );
+
+  // MySQL (mysql_client): `MySQLServerException [1054]: Unknown column ...`.
+  static final _mysql = RegExp(r'MySQLServerException \[\d+\]: ([^\n]+)');
+
+  /// The `SELECT * FROM (\n<sql>\n)` that keeps SQLite column names unique
+  /// (#1144), with the row limit the app adds after it.
+  static final _wrapper = RegExp(
+    r'SELECT \* FROM \(\n([\s\S]*?)\n\)(?:\s*LIMIT \d+(?:\s+OFFSET \d+)?)?',
+  );
+
+  // Offsets count from the start of the wrapper, not of the user's text.
+  static final _position = RegExp(r' \(at position \d+\)');
+
+  static String _unwrap(String raw) {
+    if (!_wrapper.hasMatch(raw)) return raw;
+    return raw
+        .replaceAllMapped(_wrapper, (m) => m[1]!)
+        .replaceAll(_position, '');
+  }
+
+  static String _summary(String detail) {
+    for (final pattern in [_sqlite, _postgres, _mysql]) {
+      final m = pattern.firstMatch(detail);
+      final message = m?.group(1)?.trim();
+      if (message != null && message.isNotEmpty) return _cap(message);
+    }
+    final first = detail
+        .split('\n')
+        .map((l) => l.trim())
+        .firstWhere((l) => l.isNotEmpty, orElse: () => detail);
+    return _cap(first.startsWith('Exception: ') ? first.substring(11) : first);
+  }
+
+  static String _cap(String s) =>
+      s.length <= _maxSummary ? s : '${s.substring(0, _maxSummary)}…';
+}

lib/features/workspace/results_tab.dart

@@ -4,6 +4,7 @@ import 'package:flutter/material.dart' as material;
 import 'package:flutter/services.dart';
 import 'package:querya_desktop/core/security/pii_masking_controller.dart';
 import 'package:querya_desktop/core/actions/data_grid_command_bridge.dart';
+import 'package:querya_desktop/core/database/query_error_text.dart';
 import 'package:querya_desktop/core/widgets/virtual_selectable_text_view.dart';
 import 'package:querya_desktop/features/results/charts/quick_chart_view.dart';
 import 'package:querya_desktop/features/workspace/data_grid_calc_bar.dart';
@@ -84,6 +85,10 @@ class ResultsTab extends material.StatefulWidget {
 }
 
 class _ResultsTabState extends material.State<ResultsTab> {
+  /// The driver text of a query error is folded away until asked for (#1557).
+  bool _showErrorDetails = false;
+  bool _errorCopied = false;
+
   /// Selection / focus state lives in notifiers so a navigation step rebuilds
   /// only the widgets that show it (toolbar, value panel, calc bar), not the
   /// whole tab and its grid.
@@ -249,6 +254,10 @@ class _ResultsTabState extends material.State<ResultsTab> {
 
   @override
   void didUpdateWidget(covariant ResultsTab oldWidget) {
+    if (oldWidget.errorMessage != widget.errorMessage) {
+      _showErrorDetails = false;
+      _errorCopied = false;
+    }
     super.didUpdateWidget(oldWidget);
     _syncGridBridge();
     if (!identical(oldWidget.rows, widget.rows) ||
@@ -379,56 +388,109 @@ class _ResultsTabState extends material.State<ResultsTab> {
     super.dispose();
   }
 
-  @override
-  material.Widget build(material.BuildContext context) {
-    if (widget.isLoading) {
-      return const material.Center(
-        key: material.ValueKey('results_mode_loading'),
-        child: QueryaSpinner(
-          size: QueryaSpinnerSize.sm,
-          label: 'Executing query...',
-        ),
-      );
-    }
-
-    if (widget.errorMessage != null) {
-      return material.Center(
-        key: const material.ValueKey('results_mode_error'),
-        child: material.Padding(
-          padding: const material.EdgeInsets.all(32),
-          child: material.Column(
-            mainAxisAlignment: material.MainAxisAlignment.center,
-            mainAxisSize: material.MainAxisSize.min,
-            children: [
-              material.Icon(
-                material.Icons.error_outline_rounded,
-                size: 48,
-                color: Theme.of(context).colorScheme.destructive,
+  /// The driver's message as the headline, the rest (without the app's own
+  /// statement wrapping) behind "Show details", and a Copy button (#1557).
+  material.Widget _buildError(
+    material.BuildContext context,
+    QueryErrorText error,
+  ) {
+    final cs = Theme.of(context).colorScheme;
+    return material.Center(
+      key: const material.ValueKey('results_mode_error'),
+      child: material.Padding(
+        padding: const material.EdgeInsets.all(32),
+        child: material.Column(
+          mainAxisAlignment: material.MainAxisAlignment.center,
+          mainAxisSize: material.MainAxisSize.min,
+          children: [
+            material.Icon(
+              material.Icons.error_outline_rounded,
+              size: 48,
+              color: cs.destructive,
+            ),
+            const Gap(16),
+            const Text('Query Error').large().semiBold(),
+            const Gap(8),
+            material.SelectableText(
+              error.summary,
+              textAlign: material.TextAlign.center,
+              style: material.TextStyle(color: cs.foreground, fontSize: 14),
+            ),
+            if (error.hasDetail) ...[
+              const Gap(12),
+              material.Row(
+                mainAxisSize: material.MainAxisSize.min,
+                children: [
+                  QueryaButton.ghost(
+                    label: _showErrorDetails ? 'Hide details' : 'Show details',
+                    icon: _showErrorDetails
+                        ? material.Icons.expand_less_rounded
+                        : material.Icons.expand_more_rounded,
+                    size: QueryaControlSize.sm,
+                    onPressed: () => setState(
+                      () => _showErrorDetails = !_showErrorDetails,
+                    ),
+                  ),
+                  const Gap(6),
+                  QueryaButton.ghost(
+                    label: _errorCopied ? 'Copied' : 'Copy error',
+                    icon: _errorCopied
+                        ? material.Icons.check_rounded
+                        : material.Icons.copy_rounded,
+                    size: QueryaControlSize.sm,
+                    onPressed: () => unawaited(_copyError(error.detail)),
+                  ),
+                ],
               ),
-              const Gap(16),
-              const Text('Query Error').large().semiBold(),
+            ],
+            if (error.hasDetail && _showErrorDetails) ...[
               const Gap(8),
               // A long driver message scrolls inside the space left, instead
               // of pushing the column past the pane.
               material.Flexible(
                 child: VirtualSelectableTextView(
-                  text: widget.errorMessage!,
+                  text: error.detail,
                   style: material.TextStyle(
-                    color: Theme.of(context).colorScheme.mutedForeground,
+                    color: cs.mutedForeground,
                     fontSize: 13,
                   ),
                 ),
               ),
-              if (widget.errorAction != null) ...[
-                const Gap(16),
-                widget.errorAction!,
-              ],
             ],
-          ),
+            if (widget.errorAction != null) ...[
+              const Gap(16),
+              widget.errorAction!,
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+
+  Future<void> _copyError(String text) async {
+    await Clipboard.setData(ClipboardData(text: text));
+    if (!mounted) return;
+    setState(() => _errorCopied = true);
+    await Future<void>.delayed(const Duration(seconds: 2));
+    if (mounted) setState(() => _errorCopied = false);
+  }
+
+  @override
+  material.Widget build(material.BuildContext context) {
+    if (widget.isLoading) {
+      return const material.Center(
+        key: material.ValueKey('results_mode_loading'),
+        child: QueryaSpinner(
+          size: QueryaSpinnerSize.sm,
+          label: 'Executing query...',
         ),
       );
     }
 
+    if (widget.errorMessage != null) {
+      return _buildError(context, QueryErrorText.parse(widget.errorMessage!));
+    }
+
     if (widget.columns.isEmpty && widget.rows.isEmpty && widget.stagingBuffer == null) {
       if (widget.statusLine != null) {
         return material.Padding(

test/core/database/query_error_text_test.dart

@@ -0,0 +1,73 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:querya_desktop/core/database/query_error_text.dart';
+
+void main() {
+  group('QueryErrorText (#1557)', () {
+    // The example from the issue, as sqflite_common_ffi prints it.
+    const sqlite =
+        'SqliteFfiException(sqlite_error: 1, , SqliteException(1): while preparing '
+        'statement, no such column: u.name, SQL logic error (code 1)\n'
+        '  Causing statement (at position 29): SELECT * FROM (\n'
+        'SELECT o.id, u.name FROM orders o JOIN users u ON u.id = o.user_id '
+        'ORDER BY o.id LIMIT 200\n'
+        ')\n'
+        'LIMIT 5000}) DatabaseException(SqliteException(1): while preparing '
+        'statement, no such column: u.name, SQL logic error (code 1)\n'
+        '  Causing statement (at position 29): SELECT * FROM (\n'
+        'SELECT o.id, u.name FROM orders o JOIN users u ON u.id = o.user_id '
+        'ORDER BY o.id LIMIT 200\n'
+        ')';
+
+    test('SQLite: the message alone, without the wrapper or its position', () {
+      final e = QueryErrorText.parse(sqlite);
+      expect(e.summary, 'no such column: u.name');
+      expect(e.hasDetail, isTrue);
+      expect(e.detail, isNot(contains('SELECT * FROM (')));
+      expect(e.detail, isNot(contains('LIMIT 5000')));
+      expect(e.detail, isNot(contains('at position')));
+      expect(e.detail, contains('ORDER BY o.id LIMIT 200'));
+      expect(e.detail, contains('no such column: u.name'));
+    });
+
+    test('PostgreSQL: the server message, without detail and hint', () {
+      final e = QueryErrorText.parse(
+        'Severity.error 42703: column "nme" does not exist hint: Perhaps you meant "name".',
+      );
+      expect(e.summary, 'column "nme" does not exist');
+      expect(e.detail, contains('hint: Perhaps'));
+    });
+
+    test('MySQL: the server message after the error code', () {
+      final e = QueryErrorText.parse(
+        "MySQLServerException [1054]: Unknown column 'nme' in 'field list'",
+      );
+      expect(e.summary, "Unknown column 'nme' in 'field list'");
+    });
+
+    test('anything else: its first line; one line has no extra detail', () {
+      final one = QueryErrorText.parse('connection refused');
+      expect(one.summary, 'connection refused');
+      expect(one.hasDetail, isFalse);
+
+      final two = QueryErrorText.parse('Exception: socket closed\nat line 3');
+      expect(two.summary, 'socket closed');
+      expect(two.hasDetail, isTrue);
+    });
+
+    test('text without the wrapper is left as it is', () {
+      const raw = 'SqliteException(1): while preparing statement, near "SELEC": '
+          'syntax error, SQL logic error (code 1)\n'
+          '  Causing statement (at position 0): SELEC 1';
+      final e = QueryErrorText.parse(raw);
+      expect(e.summary, 'near "SELEC": syntax error');
+      expect(e.detail, raw);
+    });
+
+    test('a very long message is cut in the summary only', () {
+      final long = 'x' * 1000;
+      final e = QueryErrorText.parse(long);
+      expect(e.summary.length, lessThan(320));
+      expect(e.detail, long);
+    });
+  });
+}