Flutter Query Testing

Comprehensive guide for validating Flutter Supabase queries against database schema, testing them locally, and integrating into CI/CD pipelines. Catch query errors before they reach production.

Table of Contents

1. When to Use
2. Quick Reference
3. Query Patterns in Ballee
4. Static Analysis
5. Live Testing
6. RLS Testing
7. Integration Testing
8. CI/CD Integration
9. Common Issues
10. Related Skills

When to Use

DO use this skill when:

• Validating queries before merging PRs
• Debugging "column does not exist" errors
• After database schema changes
• Setting up query testing pipelines
• Writing integration tests for API layer
• Testing RLS policy behavior

DO NOT use this skill when:

• Issue is clearly UI-related (not API)
• Debugging non-Supabase Flutter code
• Working on web app queries (use

  db-lint-manager

  )

Quick Reference

Run Validation Scripts

# Static analysis (no DB needed)
cd apps/mobile
dart run scripts/validate_queries.dart

# Live testing (requires local Supabase)
dart run scripts/test_queries_local.dart

# Generate full report
dart run scripts/generate_query_report.dart

Pre-commit Hook (automatic)

# Already configured in lefthook.yml
pre-commit:
  flutter-query-static:
    glob: "apps/mobile/lib/**/api/**/*.dart"
    run: cd apps/mobile && dart run scripts/validate_queries.dart --changed-only

Query Patterns in Ballee

Generated Type Constants

Ballee uses generated Supabase types in

lib/core/generated/supabase/

// Table names
CastAssignment.table_name  // 'cast_assignments'
EventParticipant.table_name  // 'event_participants'

// Column names (prefixed with c_)
CastAssignment.c_userId  // 'user_id'
CastAssignment.c_assignmentStatus  // 'assignment_status'
Profile.c_firstName  // 'first_name'

Query Patterns

// Simple query with generated constants
await _client
    .from(CastAssignment.table_name)
    .select()
    .eq(CastAssignment.c_userId, userId);

// Nested relationships
await _client
    .from(Conversations.table_name)
    .select('''
      *,
      participants:${ConversationParticipants.table_name}!inner(
        *,
        profile:${Profile.table_name}!conversation_participants_user_id_profiles_fkey(
          ${Profile.c_id},
          ${Profile.c_firstName}
        )
      )
    ''');

// RPC calls
await _client.rpc(
  'get_or_create_direct_conversation',
  params: {'p_other_user_id': otherUserId},
);

Static Analysis

Static analysis validates queries without running them.

What It Checks

Table 'event_participations' not found

Column 'name' not found on 'events'

Unknown relationship 'venue' on 'events'

RPC 'get_user_data' not found

Profile.c_id

'id'

Algorithm

1. Parse all *_api.dart files
2. Extract Supabase calls:
   - .from('table') → table name
   - .select('columns') → column names
   - .eq('column', value) → filter column
   - .rpc('function') → RPC function
3. Load schema from lib/core/generated/supabase/
4. Validate each extracted element
5. Report errors with file:line references

Output Format

Flutter Query Static Analysis
=============================

apps/mobile/lib/modules/schedule/api/schedule_api.dart
  Line 28: ✓ .from(CastAssignment.table_name) → cast_assignments
  Line 30: ✓ .select('id, assignment_status, ...')
  Line 43: ✓ .eq(CastAssignment.c_userId, _userId)

apps/mobile/lib/modules/inbox/api/inbox_api.dart
  Line 34: ✓ .from(Conversations.table_name) → conversations
  Line 47: ✗ .eq('conversation_participants.user_id', ...)
           Warning: Consider using generated constant

Summary: 45 queries validated, 0 errors, 2 warnings

Live Testing

Live testing executes queries against local Supabase to catch runtime errors.

Prerequisites

# Start local Supabase
cd apps/web
pnpm supabase:web:start

# Verify it's running
curl http://localhost:54321/rest/v1/

What It Tests

Test Categories

// 1. Basic CRUD tests
// Verify queries execute successfully

// 2. Relationship tests
// Verify nested selects return correct structure

// 3. RLS tests
// Verify authenticated vs anonymous access

// 4. Edge case tests
// Empty results, null handling, special characters

Output Format

Flutter Query Live Testing
==========================

Testing schedule_api.dart...
  ✓ getScheduleItems() - 3 rows in 45ms
  ✓ getUpcomingItems() - 1 row in 32ms

Testing inbox_api.dart...
  ✓ getConversations() - 2 rows in 78ms
  ✓ getConversation(id) - 1 row in 25ms
  ✗ getOrCreateDirectConversation() - RLS denied
    Error: new row violates row-level security policy

Summary: 12 tests, 11 passed, 1 failed

RLS Testing

Testing Row Level Security is critical for mobile apps.

Test Patterns

// Test 1: Authenticated user access
test('authenticated user can read own data', () async {
  await signInAsTestUser();

  final result = await _client
      .from('profiles')
      .select()
      .eq('id', testUserId);

  expect(result, isNotEmpty);
});

// Test 2: Cross-user isolation
test('user cannot read other user data', () async {
  await signInAsTestUser();

  final result = await _client
      .from('profiles')
      .select()
      .eq('id', otherUserId);

  expect(result, isEmpty); // RLS blocks access
});

// Test 3: Anonymous access
test('anonymous cannot access protected tables', () async {
  await signOut();

  expect(
    () => _client.from('profiles').select(),
    throwsA(isA<PostgrestException>()),
  );
});

// Test 4: Write permissions
test('user can only update own profile', () async {
  await signInAsTestUser();

  // Should succeed
  await _client
      .from('profiles')
      .update({'bio': 'updated'})
      .eq('id', testUserId);

  // Should fail (RLS)
  expect(
    () => _client
        .from('profiles')
        .update({'bio': 'hacked'})
        .eq('id', otherUserId),
    throwsA(isA<PostgrestException>()),
  );
});

RLS Test Matrix

Integration Testing

Full integration tests for API classes.

Test Setup

// test/modules/schedule/schedule_api_test.dart
import 'package:flutter_test/flutter_test.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

void main() {
  late SupabaseClient client;
  late ScheduleApi api;

  setUpAll(() async {
    // Initialize Supabase with local instance
    await Supabase.initialize(
      url: 'http://localhost:54321',
      anonKey: 'eyJ...', // Local anon key
    );
    client = Supabase.instance.client;
    api = ScheduleApi(client);
  });

  setUp(() async {
    // Sign in as test user before each test
    await client.auth.signInWithPassword(
      email: 'test@example.com',
      password: 'test123',
    );
  });

  tearDown(() async {
    await client.auth.signOut();
  });

  group('ScheduleApi', () {
    test('getScheduleItems returns items within date range', () async {
      final items = await api.getScheduleItems(
        startDate: DateTime(2026, 1, 1),
        endDate: DateTime(2026, 1, 31),
      );

      expect(items, isA<List<ScheduleItemEntity>>());
      for (final item in items) {
        expect(item.startDateTime.isAfter(DateTime(2026, 1, 1)), isTrue);
        expect(item.startDateTime.isBefore(DateTime(2026, 1, 31)), isTrue);
      }
    });

    test('getUpcomingItems returns next 30 days', () async {
      final items = await api.getUpcomingItems();

      final now = DateTime.now();
      final thirtyDaysLater = now.add(Duration(days: 30));

      for (final item in items) {
        expect(item.startDateTime.isAfter(now), isTrue);
        expect(item.startDateTime.isBefore(thirtyDaysLater), isTrue);
      }
    });
  });
}

Mock Setup for Unit Tests

// For unit tests without DB, mock the Supabase client
import 'package:mocktail/mocktail.dart';

class MockSupabaseClient extends Mock implements SupabaseClient {}
class MockSupabaseQueryBuilder extends Mock implements SupabaseQueryBuilder {}

void main() {
  late MockSupabaseClient mockClient;
  late ScheduleApi api;

  setUp(() {
    mockClient = MockSupabaseClient();
    api = ScheduleApi(mockClient);

    // Setup mock responses
    final mockQueryBuilder = MockSupabaseQueryBuilder();
    when(() => mockClient.from(any())).thenReturn(mockQueryBuilder);
    when(() => mockQueryBuilder.select(any())).thenReturn(mockQueryBuilder);
    when(() => mockQueryBuilder.eq(any(), any())).thenReturn(mockQueryBuilder);
    when(() => mockQueryBuilder.execute()).thenAnswer(
      (_) async => PostgrestResponse(data: [], count: 0),
    );
  });

  test('calls correct table', () async {
    await api.getUpcomingItems();
    verify(() => mockClient.from('cast_assignments')).called(1);
  });
}

CI/CD Integration

GitHub Actions Workflow

# .github/workflows/flutter-quality.yml
name: Flutter Quality

on:
  push:
    paths:
      - 'apps/mobile/**'
  pull_request:
    paths:
      - 'apps/mobile/**'

jobs:
  query-validation:
    runs-on: ubuntu-latest

    services:
      postgres:
        image: supabase/postgres:15.1.0.147
        env:
          POSTGRES_PASSWORD: postgres
        ports:
          - 54322:5432

    steps:
      - uses: actions/checkout@v4

      - uses: subosito/flutter-action@v2
        with:
          flutter-version: '3.24.0'
          channel: 'stable'

      - name: Install dependencies
        run: cd apps/mobile && flutter pub get

      - name: Static Query Validation
        run: cd apps/mobile && dart run scripts/validate_queries.dart

      - name: Setup Supabase
        run: |
          cd apps/web
          npx supabase start

      - name: Live Query Testing
        run: cd apps/mobile && dart run scripts/test_queries_local.dart

      - name: Generate Report
        run: cd apps/mobile && dart run scripts/generate_query_report.dart

      - name: Upload Report
        uses: actions/upload-artifact@v4
        with:
          name: query-report
          path: apps/mobile/query-report.md

Pre-commit Hook

# lefthook.yml (additions)
pre-commit:
  commands:
    flutter-query-static:
      glob: "apps/mobile/lib/**/api/**/*.dart"
      run: |
        cd apps/mobile && dart run scripts/validate_queries.dart --changed-only
      fail_text: "Flutter query static validation failed"

pre-push:
  commands:
    flutter-query-live:
      glob: "apps/mobile/**/*.dart"
      run: |
        if pgrep -f "supabase" > /dev/null; then
          cd apps/mobile && dart run scripts/test_queries_local.dart
        else
          echo "Skipping live query tests (Supabase not running)"
        fi
      fail_text: "Flutter query live testing failed"

Schema Sync Hook

#!/bin/bash
# apps/mobile/scripts/sync_schema.sh

set -e

echo "Regenerating Supabase types..."
cd ../web
npx supabase gen types dart --local > ../mobile/lib/core/generated/supabase/schema.dart

echo "Validating queries against new schema..."
cd ../mobile
dart run scripts/validate_queries.dart

echo "Schema sync complete!"

Common Issues

Issue: Column Not Found

Error: Column 'name' not found on table 'events'
Suggestion: Did you mean 'title'?

Fix: Use the correct column name. Check generated types in

lib/core/generated/supabase/

Issue: Invalid FK Reference

Error: Unknown relationship 'venue' on 'events'

Fix: Use explicit FK syntax:

// Before
'venue(name, city)'

// After
'venue:venues!events_venue_id_fkey(name, city)'

Issue: RPC Function Not Found

Error: RPC function 'get_user_data' not found

Fix: Verify function exists in migrations or create it:

CREATE OR REPLACE FUNCTION get_user_data(p_user_id uuid)
RETURNS json AS $$
  -- function body
$$ LANGUAGE sql SECURITY DEFINER;

Issue: Generated Types Out of Date

Warning: Using hardcoded 'user_id' instead of Profile.c_userId

Fix: Regenerate types:

cd apps/web && pnpm supabase:web:typegen

Issue: RLS Blocks Query

Error: new row violates row-level security policy

Fix: Check RLS policies in

apps/web/supabase/migrations/

• Missing

  is_super_admin()

  bypass
• Incorrect

  USING

  clause
• Missing

  WITH CHECK

  for INSERT/UPDATE

Related Skills

• flutter-query-lint: Basic static linting (superseded by this skill)
• flutter-development: General Flutter patterns
• flutter-testing: Test patterns for all Flutter code
• database-migration-manager: Creating schema changes
• rls-policy-generator: Writing RLS policies
• test-patterns: Web E2E test patterns (similar RLS testing)

Files Reference

API Files

apps/mobile/lib/modules/*/api/*_api.dart
apps/mobile/lib/core/data/api/*_api.dart

Generated Types

apps/mobile/lib/core/generated/supabase/*.dart

Scripts

apps/mobile/scripts/validate_queries.dart
apps/mobile/scripts/test_queries_local.dart
apps/mobile/scripts/generate_query_report.dart
apps/mobile/scripts/sync_schema.sh

Test Files

apps/mobile/test/modules/*/api/*_api_test.dart