Flutter Query Linter

Flutter Query Linter

Validates Supabase queries in Flutter API files against the database schema (database.types.ts). Reports mismatches in table names, column names, relationships, and RPC function calls.

When to Use This Skill

DO use this skill when:

• Debugging Flutter API query failures
• Before pushing mobile app changes that modify queries
• After database schema changes to check for breaking changes
• Investigating "column does not exist" or similar errors
• Reviewing PRs that touch Flutter API files

DO NOT use this skill when:

• Writing new queries (just write them, then validate)
• The issue is clearly RLS/​permissions related (not schema)
• Debugging non-query Flutter issues

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Quick Reference

Run the Linter

# From project root
npx ts-node .claude/​skills/​flutter-query-lint/​scripts/​lint-queries.ts

Output Format

The linter produces a markdown report with:

• Errors: Invalid table/​column names, missing relationships
• Warnings: RPC functions that may have issues
• Summary: Statistics on validated queries

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Query Patterns Detected

Table Queries

.from('table_name')

Column Selections

// Simple
.select('col1, col2, col3')

// With relationships
.select('*, relation_name(col1, col2)')

// Aliased relationships
.select('alias:table_name!foreign_key(col1, col2)')

// Multiline
.select('''
  col1,
  col2,
  relation(nested_col)
''')

Filters

.eq('column', value)
.inFilter('column', ['values'])
.gte('column', value)
.lte('column', value)
.neq('column', value)

RPC Calls

.rpc('function_name')
.rpc('function_name', params: {...})

Ordering

.order('column', ascending: true)

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Validation Rules

1. Table Existence

Checks that the table name in .from('table') exists in database.types.ts.

2. Column Existence

For each column in .select(), .eq(), .order(), etc., validates it exists on the target table.

Note: The linter handles:

• * wildcard (skipped)
• Nested relationships like relation(col1, col2)
• Aliased relationships like alias:table!fk(col1)

3. Relationship Resolution

For relationship queries like:

.select('productions(id, name)')

Validates that productions is either:

• A valid table name (implicit FK)
• An alias with explicit FK reference

4. RPC Function Existence

Checks .rpc('function_name') against Functions in database.types.ts.

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Common Issues

Missing Column

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

Fix: Update the query to use the correct column name.

Invalid Table

Error: Table 'event_participations' does not exist
Suggestion: Did you mean 'event_participants'?

Fix: Use the correct table name.

Unknown Relationship

Warning: Relationship 'venue' on 'events' cannot be validated

Note: May be valid if using implicit FK. Check manually.

Missing RPC Function

Error: RPC function 'get_user_events' does not exist

Fix: Either create the function or remove the call.

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Integration with Development Workflow

Before Committing Mobile Changes

# Run lint before committing API changes
npx ts-node .claude/​skills/​flutter-query-lint/​scripts/​lint-queries.ts

After Schema Changes

When you modify the database schema:

1. Regenerate types: pnpm supabase:web:typegen
2. Run Flutter query lint to find broken queries
3. Fix any reported issues

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Files Scanned

The linter scans:

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

Schema Source

Validation uses:

apps/​web/​supabase/​database.types.ts

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Limitations

1. Dynamic queries: Cannot validate queries built dynamically at runtime
2. Computed columns: Views may have columns not in base tables
3. Complex select strings: Very complex nested selections may not parse correctly
4. RPC return types: Doesn't validate RPC parameter types or return values

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Related Skills

• db-lint-manager: For PostgreSQL function validation
• database-migration-manager: For creating schema migrations
• flutter-development: For Flutter patterns and best practices