Module: TheSchemaIs::Cops::Parser

Defined in:
lib/the_schema_is/cops/parser.rb

Defined Under Namespace

Classes: Column, Model

Constant Summary collapse

STANDARD_COLUMN_TYPES =

See github.com/rails/rails/blob/f33d52c95217212cbacc8d5e44b5a8e3cdc6f5b3/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb#L217 TODO: numeric is just an alias for decimal TODO: different adapters can add another types edgeguides.rubyonrails.org/active_record_postgresql.html

%i[bigint binary boolean date datetime decimal numeric
float integer json string text time timestamp virtual].freeze
POSTGRES_COLUMN_TYPES = 
%i[jsonb inet cidr macaddr hstore uuid].freeze
COLUMN_DEFS = 
(STANDARD_COLUMN_TYPES + POSTGRES_COLUMN_TYPES + %i[enum column]).freeze

Class Method Summary collapse

Class Method Details

.base_classes_query(classes) ⇒ Object 



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# File 'lib/the_schema_is/cops/parser.rb', line 81

def self.base_classes_query(classes)
  classes
    .map { |cls| cls.split('::').inject('nil?') { |res, str| "(const #{res} :#{str})" } }
    .join(' ')
    .then { |str| "{#{str}}" }
end

.columns(ast) ⇒ Object 



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# File 'lib/the_schema_is/cops/parser.rb', line 88

def self.columns(ast)
  ast.arraify.map { |node|
    # FIXME: Of course it should be easier to say "optional additional params"
    if (type, name, defs =
          node.ast_match('(send {(send nil? :t) (lvar :t)} $_ (str $_) $_)'))
      Column.new(name: name, type: type, definition: defs, source: node) \
        if COLUMN_DEFS.include?(type)
    elsif (type, name = node.ast_match('(send {(send nil? :t) (lvar :t)} $_ (str $_))'))
      Column.new(name: name, type: type, source: node) if COLUMN_DEFS.include?(type)
    end
  }.compact
end

.model(ast, base_classes: %w[ActiveRecord::Base ApplicationRecord],, table_prefix: nil) ⇒ Object 



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# File 'lib/the_schema_is/cops/parser.rb', line 44

def self.model(ast, base_classes: %w[ActiveRecord::Base ApplicationRecord], table_prefix: nil)
  base = base_classes_query(base_classes)
  ast.ast_search("$(class $_ #{base} _)")
     .map { |node, name| node2model(name, node, table_prefix.to_s) }
     .compact
     .first
end

.node2model(name_node, definition_node, table_prefix) ⇒ Object

rubocop:disable Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity



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# File 'lib/the_schema_is/cops/parser.rb', line 52

def self.node2model(name_node, definition_node, table_prefix) # rubocop:disable Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity
  return if definition_node.ast_search('(send self :abstract_class= true)')&.any?

  # If all children are classes/modules -- model is here only as a namespace, shouldn't be
  # parsed/have the_schema_is
  if definition_node.children&.dig(2)&.arraify&.all? { |n| %i[class module].include?(n.type) }
    return
  end

  class_name = name_node.loc.expression.source

  schema_node, name_node =
    definition_node.ast_search('$(block (send nil? :the_schema_is $_?) _ ...)')&.last

  # TODO: https://api.rubyonrails.org/classes/ActiveRecord/ModelSchema/ClassMethods.html#method-i-table_name
  # * consider table_prefix/table_suffix settings
  # * also, consider engines!
  table_name = definition_node.ast_search('(send self :table_name= (str $_))')&.last

  Model.new(
    class_name: class_name,
    table_name: table_name ||
      table_prefix.+(ActiveSupport::Inflector.tableize(class_name)),
    source: definition_node,
    schema: schema_node,
    table_name_node: name_node&.first
  )
end

.parse(code) ⇒ Object 



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# File 'lib/the_schema_is/cops/parser.rb', line 31

def self.parse(code)
  # TODO: Some kind of "current version" (ask Rubocop!)
  RuboCop::AST::ProcessedSource.new(code, 2.7).ast
end

.remove_attributes(ast, attrs_to_remove) ⇒ Object

Removes unnecessary column definitions from further comparison, using schema source tree editing



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# File 'lib/the_schema_is/cops/parser.rb', line 102

def self.remove_attributes(ast, attrs_to_remove)
  buf = ast.loc.expression.source_buffer
  src = buf.source
  rewriter = ::Parser::Source::TreeRewriter.new(buf)

  # FIXME: Two nested cycles can be simplifid to just look for column definition, probably
  ast.ast_search('(block (send nil? :create_table (str _) _) _ $_)').each do |table_def|
    table_def.children.each do |col|
      dfn = col.children[3] or next
      dfn.children
         .select { |c| attrs_to_remove.include?(c.children[0].children[0]) }
         .each do |c|
        prev_comma = c.source_range.begin_pos.step(by: -1).find { |pos| src[pos] == ',' }
        range = ::Parser::Source::Range.new(buf, prev_comma, c.source_range.end_pos)
        rewriter.remove(range)
      end
    end
  end

  RuboCop::AST::ProcessedSource.new(rewriter.process, 2.7).ast
end

.schema(path, remove_definition_attrs: []) ⇒ Object 



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# File 'lib/the_schema_is/cops/parser.rb', line 36

def self.schema(path, remove_definition_attrs: [])
  ast = parse(File.read(path))

  ast = remove_attributes(ast, remove_definition_attrs) unless remove_definition_attrs.empty?

  ast.ast_search('(block (send nil? :create_table (str $_) _) _ $_)').to_h
end