Class: Rhales::SchemaGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/rhales/utils/schema_generator.rb

Overview

Generates JSON Schemas from Zod schemas using TypeScript execution

This class uses pnpm exec tsx to execute Zod schema code and convert it to JSON Schema format. The generated schemas are saved to disk for use by the validation middleware.

Usage: generator = SchemaGenerator.new( templates_dir: ‘./templates’, output_dir: ‘./public/schemas’ ) results = generator.generate_all

Defined Under Namespace

Classes: GenerationError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(templates_dir:, output_dir: nil) ⇒ SchemaGenerator

Returns a new instance of SchemaGenerator.

Parameters:

  • templates_dir (String) —

    Directory containing .rue files

  • output_dir (String) (defaults to: nil) —

    Directory to save generated JSON schemas Defaults to ‘./public/schemas’ (implementing project’s public directory)



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# File 'lib/rhales/utils/schema_generator.rb', line 33

def initialize(templates_dir:, output_dir: nil)
  @templates_dir = File.expand_path(templates_dir)

  # Smart default: place schemas in public/schemas relative to current working directory
  # This ensures schemas are generated in the implementing project, not the gem directory
  @output_dir = if output_dir
    File.expand_path(output_dir)
  else
    # Default to public/schemas in current working directory
    File.expand_path('./public/schemas')
  end

  validate_setup!
  ensure_output_directory!
end

Instance Attribute Details

#output_dir ⇒ Object (readonly)

Returns the value of attribute output_dir.



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# File 'lib/rhales/utils/schema_generator.rb', line 28

def output_dir
  @output_dir
end

#templates_dir ⇒ Object (readonly)

Returns the value of attribute templates_dir.



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# File 'lib/rhales/utils/schema_generator.rb', line 28

def templates_dir
  @templates_dir
end

Instance Method Details

#build_typescript_import_script(schema_info) ⇒ Array<String, String> (private)

Build TypeScript script from bundled external schema

Uses esbuild to bundle the external schema with all imports resolved, writes to a temp file, then imports via default export. This allows external files to name their schema variable anything they want.

External schema files must use default export: const mySchema = z.object({ … }); export default mySchema;

Parameters:

  • schema_info (Hash) —

    Schema information with resolved_path

Returns:

  • (Array<String, String>) —

    [script content, bundled_file_path] - caller must clean up bundled file



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# File 'lib/rhales/utils/schema_generator.rb', line 182

def build_typescript_import_script(schema_info)
  safe_name = schema_info[:template_name].gsub("'", "\\'")
  schema_path = schema_info[:resolved_path]

  # Bundle external schema with esbuild to temp file - resolves all imports
  # Use SecureRandom for uniqueness across concurrent invocations
  temp_dir = File.join(Dir.pwd, 'tmp')
  FileUtils.mkdir_p(temp_dir) unless Dir.exist?(temp_dir)
  unique_suffix = "#{Process.pid}_#{SecureRandom.hex(4)}"
  bundled_file = File.join(temp_dir, "bundled_#{File.basename(schema_path, '.*')}_#{unique_suffix}.mjs")

  stdout, stderr, status = Open3.capture3(
    'pnpm', 'exec', 'esbuild', schema_path,
    '--bundle', '--format=esm', '--platform=node',
    '--external:zod',
    "--outfile=#{bundled_file}"
  )

  unless status.success?
    raise GenerationError, "esbuild bundling failed for #{schema_path}: #{stderr}"
  end

  # Convert to file:// URL for cross-platform ESM import compatibility
  bundled_file_url = path_to_file_url(bundled_file)

  script = <<~TYPESCRIPT
    // Auto-generated schema generator for #{safe_name}
    // Source: #{schema_info[:src]} (bundled via esbuild)
    import { z } from 'zod/v4';
    import schema from '#{bundled_file_url}';

    // Generate JSON Schema
    try {
      const jsonSchema = z.toJSONSchema(schema, {
        target: 'draft-2020-12',
        unrepresentable: 'any',
        cycles: 'ref',
        reused: 'inline',
      });

      // Add metadata
      const schemaWithMeta = {
        $schema: 'https://json-schema.org/draft/2020-12/schema',
        $id: `https://rhales.dev/schemas/#{safe_name}.json`,
        title: '#{safe_name}',
        description: 'Schema for #{safe_name} template',
        ...jsonSchema,
      };

      // Output JSON to stdout
      console.log(JSON.stringify(schemaWithMeta, null, 2));
    } catch (error) {
      console.error('Schema generation error:', error.message);
      process.exit(1);
    }
  TYPESCRIPT

  [script, bundled_file]
end

#build_typescript_script(schema_info) ⇒ Object (private) 



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# File 'lib/rhales/utils/schema_generator.rb', line 242

def build_typescript_script(schema_info)
  # Escape single quotes in template name for TypeScript string
  safe_name = schema_info[:template_name].gsub("'", "\\'")
  source_comment = if schema_info[:src]
    "// Source: #{schema_info[:src]} (external)"
  else
    "// Source: inline schema"
  end

  <<~TYPESCRIPT
    // Auto-generated schema generator for #{safe_name}
    #{source_comment}
    import { z } from 'zod/v4';

    // Schema code from .rue template
    #{schema_info[:schema_code].strip}

    // Generate JSON Schema
    try {
      const jsonSchema = z.toJSONSchema(schema, {
        target: 'draft-2020-12',
        unrepresentable: 'any',
        cycles: 'ref',
        reused: 'inline',
      });

      // Add metadata
      const schemaWithMeta = {
        $schema: 'https://json-schema.org/draft/2020-12/schema',
        $id: `https://rhales.dev/schemas/#{safe_name}.json`,
        title: '#{safe_name}',
        description: 'Schema for #{safe_name} template',
        ...jsonSchema,
      };

      // Output JSON to stdout
      console.log(JSON.stringify(schemaWithMeta, null, 2));
    } catch (error) {
      console.error('Schema generation error:', error.message);
      process.exit(1);
    }
  TYPESCRIPT
end

#ensure_output_directory! ⇒ Object (private) 



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# File 'lib/rhales/utils/schema_generator.rb', line 321

def ensure_output_directory!
  FileUtils.mkdir_p(@output_dir) unless File.directory?(@output_dir)
end

#execute_tsx(script_path) ⇒ Array (private)

Execute tsx with optional tsconfig

Parameters:

  • script_path (String) —

    Path to the TypeScript script to execute

Returns:

  • (Array) —

    stdout, stderr, status from Open3.capture3



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# File 'lib/rhales/utils/schema_generator.rb', line 155

def execute_tsx(script_path)
  tsconfig_path = Rhales.configuration.schema_tsconfig_path

  if tsconfig_path
    if File.exist?(tsconfig_path)
      Open3.capture3('pnpm', 'exec', 'tsx', '--tsconfig', tsconfig_path, script_path)
    else
      warn "[Rhales] Warning: schema_tsconfig_path '#{tsconfig_path}' does not exist, ignoring"
      Open3.capture3('pnpm', 'exec', 'tsx', script_path)
    end
  else
    Open3.capture3('pnpm', 'exec', 'tsx', script_path)
  end
end

#generate_all ⇒ Hash

Generate JSON Schemas for all templates with sections

Returns:

  • (Hash) —

    Generation results with stats



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# File 'lib/rhales/utils/schema_generator.rb', line 52

def generate_all
  extractor = SchemaExtractor.new(@templates_dir)
  schemas = extractor.extract_all

  if schemas.empty?
    return {
      success: true,
      generated: 0,
      failed: 0,
      message: 'No schemas found in templates'
    }
  end

  results = {
    success: true,
    generated: 0,
    failed: 0,
    errors: []
  }

  schemas.each do |schema_info|
    begin
      generate_schema(schema_info)
      results[:generated] += 1
      puts "✓ Generated schema for: #{schema_info[:template_name]}"
    rescue => e
      results[:failed] += 1
      results[:success] = false
      source_info = schema_info[:src] ? " (from #{schema_info[:src]})" : ""
      error_msg = "Failed to generate schema for #{schema_info[:template_name]}#{source_info}: #{e.message}"
      results[:errors] << error_msg
      warn error_msg
    end
  end

  results
end

#generate_schema(schema_info) ⇒ Hash

Generate JSON Schema for a single template

Parameters:

  • schema_info (Hash) —

    Schema information from SchemaExtractor

Returns:

  • (Hash) —

    Generated JSON Schema



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# File 'lib/rhales/utils/schema_generator.rb', line 94

def generate_schema(schema_info)
  # Create temp file in project directory so Node.js can resolve modules
  temp_dir = File.join(Dir.pwd, 'tmp')
  FileUtils.mkdir_p(temp_dir) unless Dir.exist?(temp_dir)

  temp_file = Tempfile.new(['schema', '.mts'], temp_dir)
  bundled_file = nil

  begin
    # Write TypeScript script - use import mode for external schemas when configured
    if use_tsx_import_mode?(schema_info)
      script, bundled_file = build_typescript_import_script(schema_info)
    else
      script = build_typescript_script(schema_info)
    end
    temp_file.write(script)
    temp_file.close

    # Execute with tsx via pnpm, optionally with tsconfig
    stdout, stderr, status = execute_tsx(temp_file.path)

    unless status.success?
      raise GenerationError, "TypeScript execution failed: #{stderr}"
    end

    # Parse JSON Schema from stdout
    json_schema = JSONSerializer.parse(stdout)

    # Save to disk
    save_schema(schema_info[:template_name], json_schema)

    json_schema
  ensure
    temp_file.unlink if temp_file
    File.unlink(bundled_file) if bundled_file && File.exist?(bundled_file)
  end
end

#path_to_file_url(path) ⇒ String (private)

Convert absolute path to file:// URL for cross-platform ESM imports

On Windows, paths like C:\foo\bar need to become file:///C:/foo/bar On Unix, paths like /foo/bar become file:///foo/bar

Parameters:

  • path (String) —

    Absolute file path

Returns:

  • (String) —

    file:// URL



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# File 'lib/rhales/utils/schema_generator.rb', line 332

def path_to_file_url(path)
  normalized = path.tr('\\', '/')
  if normalized.match?(%r{^[A-Za-z]:}) # Windows drive letter
    "file:///#{normalized}"
  else
    "file://#{normalized}"
  end
end

#save_schema(template_name, json_schema) ⇒ Object (private) 



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# File 'lib/rhales/utils/schema_generator.rb', line 286

def save_schema(template_name, json_schema)
  # Create subdirectories if template name contains paths
  schema_file = File.join(@output_dir, "#{template_name}.json")
  schema_dir = File.dirname(schema_file)
  FileUtils.mkdir_p(schema_dir) unless File.directory?(schema_dir)

  File.write(schema_file, JSONSerializer.dump(json_schema))
end

#use_tsx_import_mode?(schema_info) ⇒ Boolean (private)

Determine if we should use tsx import mode for this schema

Import mode is used when: 1. schema_use_tsx_import is enabled in configuration 2. The schema has an external src (not inline) 3. The resolved_path exists

Parameters:

  • schema_info (Hash) —

    Schema information

Returns:

  • (Boolean) 


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# File 'lib/rhales/utils/schema_generator.rb', line 143

def use_tsx_import_mode?(schema_info)
  return false unless Rhales.configuration.schema_use_tsx_import
  return false unless schema_info[:src]
  return false unless schema_info[:resolved_path]

  File.exist?(schema_info[:resolved_path])
end

#validate_setup! ⇒ Object (private) 



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# File 'lib/rhales/utils/schema_generator.rb', line 295

def validate_setup!
  unless File.directory?(@templates_dir)
    raise GenerationError, "Templates directory does not exist: #{@templates_dir}"
  end

  # Check pnpm is available
  stdout, stderr, status = Open3.capture3('pnpm', '--version')
  unless status.success?
    raise GenerationError, "pnpm not found. Install pnpm to generate schemas: npm install -g pnpm"
  end

  # Check tsx is available (will be installed by pnpm if needed)
  stdout, stderr, status = Open3.capture3('pnpm', 'exec', 'tsx', '--version')
  unless status.success?
    raise GenerationError, "tsx not found. Run: pnpm install tsx --save-dev"
  end

  # Check esbuild is available when tsx import mode is enabled
  if Rhales.configuration.schema_use_tsx_import
    stdout, stderr, status = Open3.capture3('pnpm', 'exec', 'esbuild', '--version')
    unless status.success?
      raise GenerationError, "esbuild not found (required for external schema bundling). Run: pnpm install esbuild --save-dev"
    end
  end
end