Code Generation Rules

1. Only AST-based code generation

All per-schema/per-table code generation MUST use Babel AST (@babel/types + generateCode()). Never use lines.push(), string concatenation, or template literals to build generated TypeScript code.

Reference implementations:

• src/core/codegen/orm/model-generator.ts — per-table ORM model classes
• src/core/codegen/orm/client-generator.ts — createClient factory
• src/core/codegen/orm/custom-ops-generator.ts — custom query/mutation operations

2. Never any string-based concatenation

No lines.push(...), no backtick template literals containing code, no string + operators for building generated source files. If you find yourself writing lines.push(\import ...`), stop and use t.importDeclaration(...)` instead.

3. Giant templates must be actual files that get copied

Static runtime code that does not vary per-schema belongs in src/core/codegen/templates/ as real .ts files. These are read at codegen time via readTemplateFile() and written to the output directory with only the header replaced.

This gives you:

• Syntax highlighting and IDE support while editing templates
• A clear boundary between "code that generates code" and "code that IS the output"

Reference implementations:

• src/core/codegen/templates/orm-client.ts
• src/core/codegen/templates/query-builder.ts
• src/core/codegen/templates/select-types.ts