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 



81
82
83
84
85
86
 
# 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 



88
89
90
91
92
93
94
95
96
97
98
99
 
# 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 



44
45
46
47
48
49
50
 
# 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



52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# 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 



31
32
33
34
 
# 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



102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
 
# 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 



36
37
38
39
40
41
42
 
# 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