Merge pull request #34076 from gmcgibbon/fixtures_refactor

Fixtures refactor

4 files changed, 376 insertions, 243 deletions

diff --git a/activerecord/lib/active_record/fixture_set/model_metadata.rb b/activerecord/lib/active_record/fixture_set/model_metadata.rb
new file mode 100644
index 0000000000..edc03939c8
--- /dev/null
+++ b/activerecord/lib/active_record/fixture_set/model_metadata.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  class FixtureSet
+    class ModelMetadata # :nodoc:
+      def initialize(model_class, table_name)
+        @model_class = model_class
+        @table_name  = table_name
+      end
+
+      def primary_key_name
+        @primary_key_name ||= @model_class && @model_class.primary_key
+      end
+
+      def primary_key_type
+        @primary_key_type ||= @model_class && @model_class.type_for_attribute(@model_class.primary_key).type
+      end
+
+      def has_primary_key_column?
+        @has_primary_key_column ||= primary_key_name &&
+          @model_class.columns.any? { |col| col.name == primary_key_name }
+      end
+
+      def timestamp_column_names
+        @timestamp_column_names ||=
+          %w(created_at created_on updated_at updated_on) & column_names
+      end
+
+      def inheritance_column_name
+        @inheritance_column_name ||= @model_class && @model_class.inheritance_column
+      end
+
+      private
+
+        def column_names
+          @column_names ||= @model_class.connection.columns(@table_name).collect(&:name)
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/fixture_set/table_row.rb b/activerecord/lib/active_record/fixture_set/table_row.rb
new file mode 100644
index 0000000000..5f72c1df38
--- /dev/null
+++ b/activerecord/lib/active_record/fixture_set/table_row.rb
@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  class FixtureSet
+    class TableRow # :nodoc:
+      def initialize(fixture, table_rows:, label:, now:)
+        @table_rows = table_rows
+        @label = label
+        @now = now
+        @row = fixture.to_hash
+        fill_row_model_attributes
+      end
+
+      def to_hash
+        @row
+      end
+
+      private
+
+        def model_metadata
+          @table_rows.model_metadata
+        end
+
+        def model_class
+          @table_rows.model_class
+        end
+
+        def fill_row_model_attributes
+          return unless model_class
+          fill_timestamps
+          interpolate_label
+          generate_primary_key
+          resolve_enums
+          @table_rows.resolve_sti_reflections(@row)
+        end
+
+        def reflection_class
+          @reflection_class ||= if @row.include?(model_metadata.inheritance_column_name)
+            @row[model_metadata.inheritance_column_name].constantize rescue model_class
+          else
+            model_class
+          end
+        end
+
+        def fill_timestamps
+          # fill in timestamp columns if they aren't specified and the model is set to record_timestamps
+          if model_class.record_timestamps
+            model_metadata.timestamp_column_names.each do |c_name|
+              @row[c_name] = @now unless @row.key?(c_name)
+            end
+          end
+        end
+
+        def interpolate_label
+          # interpolate the fixture label
+          @row.each do |key, value|
+            @row[key] = value.gsub("$LABEL", @label.to_s) if value.is_a?(String)
+          end
+        end
+
+        def generate_primary_key
+          # generate a primary key if necessary
+          if model_metadata.has_primary_key_column? && !@row.include?(model_metadata.primary_key_name)
+            @row[model_metadata.primary_key_name] = ActiveRecord::FixtureSet.identify(
+              @label, model_metadata.primary_key_type
+            )
+          end
+        end
+
+        def resolve_enums
+          model_class.defined_enums.each do |name, values|
+            if @row.include?(name)
+              @row[name] = values.fetch(@row[name], @row[name])
+            end
+          end
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/fixture_set/table_rows.rb b/activerecord/lib/active_record/fixture_set/table_rows.rb
new file mode 100644
index 0000000000..e8335a2e10
--- /dev/null
+++ b/activerecord/lib/active_record/fixture_set/table_rows.rb
@@ -0,0 +1,129 @@
+# frozen_string_literal: true
+
+require "active_record/fixture_set/table_row"
+require "active_record/fixture_set/model_metadata"
+
+module ActiveRecord
+  class FixtureSet
+    class TableRows # :nodoc:
+      class ReflectionProxy # :nodoc:
+        def initialize(association)
+          @association = association
+        end
+
+        def join_table
+          @association.join_table
+        end
+
+        def name
+          @association.name
+        end
+
+        def primary_key_type
+          @association.klass.type_for_attribute(@association.klass.primary_key).type
+        end
+      end
+
+      class HasManyThroughProxy < ReflectionProxy # :nodoc:
+        def rhs_key
+          @association.foreign_key
+        end
+
+        def lhs_key
+          @association.through_reflection.foreign_key
+        end
+
+        def join_table
+          @association.through_reflection.table_name
+        end
+      end
+
+      def initialize(table_name, model_class:, fixtures:, config:)
+        @table_name  = table_name
+        @model_class = model_class
+
+        # track any join tables we need to insert later
+        @tables = Hash.new { |h, table| h[table] = [] }
+
+        build_table_rows_from(fixtures, config)
+      end
+
+      attr_reader :table_name, :model_class
+
+      def to_hash
+        @tables.transform_values { |rows| rows.map(&:to_hash) }
+      end
+
+      def model_metadata
+        @model_metadata ||= ModelMetadata.new(model_class, table_name)
+      end
+
+      def resolve_sti_reflections(row)
+        # If STI is used, find the correct subclass for association reflection
+        reflection_class = reflection_class_for(row)
+
+        reflection_class._reflections.each_value do |association|
+          case association.macro
+          when :belongs_to
+            # Do not replace association name with association foreign key if they are named the same
+            fk_name = (association.options[:foreign_key] || "#{association.name}_id").to_s
+
+            if association.name.to_s != fk_name && value = row.delete(association.name.to_s)
+              if association.polymorphic? && value.sub!(/\s*\(([^\)]*)\)\s*$/, "")
+                # support polymorphic belongs_to as "label (Type)"
+                row[association.foreign_type] = $1
+              end
+
+              fk_type = reflection_class.type_for_attribute(fk_name).type
+              row[fk_name] = ActiveRecord::FixtureSet.identify(value, fk_type)
+            end
+          when :has_many
+            if association.options[:through]
+              add_join_records(row, HasManyThroughProxy.new(association))
+            end
+          end
+        end
+      end
+
+      private
+
+        def build_table_rows_from(fixtures, config)
+          now = config.default_timezone == :utc ? Time.now.utc : Time.now
+
+          @tables[table_name] = fixtures.map do |label, fixture|
+            TableRow.new(
+              fixture,
+              table_rows: self,
+              label: label,
+              now: now,
+            )
+          end
+        end
+
+        def reflection_class_for(row)
+          if row.include?(model_metadata.inheritance_column_name)
+            row[model_metadata.inheritance_column_name].constantize rescue model_class
+          else
+            model_class
+          end
+        end
+
+        def add_join_records(row, association)
+          # This is the case when the join table has no fixtures file
+          if (targets = row.delete(association.name.to_s))
+            table_name  = association.join_table
+            column_type = association.primary_key_type
+            lhs_key     = association.lhs_key
+            rhs_key     = association.rhs_key
+
+            targets = targets.is_a?(Array) ? targets : targets.split(/\s*,\s*/)
+            joins   = targets.map do |target|
+              { lhs_key => row[model_metadata.primary_key_name],
+                rhs_key => ActiveRecord::FixtureSet.identify(target, column_type) }
+            end
+            @tables[table_name].concat(joins)
+          end
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index e697c30bb6..b090c76a38 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -8,6 +8,7 @@ require "active_support/dependencies"
 require "active_support/core_ext/digest/uuid"
 require "active_record/fixture_set/file"
 require "active_record/fixture_set/render_context"
+require "active_record/fixture_set/table_rows"
 require "active_record/test_fixtures"
 require "active_record/errors"
 
@@ -442,60 +443,6 @@ module ActiveRecord
 
     @@all_cached_fixtures = Hash.new { |h, k| h[k] = {} }
 
-    def self.default_fixture_model_name(fixture_set_name, config = ActiveRecord::Base) # :nodoc:
-      config.pluralize_table_names ?
-        fixture_set_name.singularize.camelize :
-        fixture_set_name.camelize
-    end
-
-    def self.default_fixture_table_name(fixture_set_name, config = ActiveRecord::Base) # :nodoc:
-      "#{ config.table_name_prefix }"\
-      "#{ fixture_set_name.tr('/', '_') }"\
-      "#{ config.table_name_suffix }".to_sym
-    end
-
-    def self.reset_cache
-      @@all_cached_fixtures.clear
-    end
-
-    def self.cache_for_connection(connection)
-      @@all_cached_fixtures[connection]
-    end
-
-    def self.fixture_is_cached?(connection, table_name)
-      cache_for_connection(connection)[table_name]
-    end
-
-    def self.cached_fixtures(connection, keys_to_fetch = nil)
-      if keys_to_fetch
-        cache_for_connection(connection).values_at(*keys_to_fetch)
-      else
-        cache_for_connection(connection).values
-      end
-    end
-
-    def self.cache_fixtures(connection, fixtures_map)
-      cache_for_connection(connection).update(fixtures_map)
-    end
-
-    def self.instantiate_fixtures(object, fixture_set, load_instances = true)
-      if load_instances
-        fixture_set.each do |fixture_name, fixture|
-          begin
-            object.instance_variable_set "@#{fixture_name}", fixture.find
-          rescue FixtureClassNotFound
-            nil
-          end
-        end
-      end
-    end
-
-    def self.instantiate_all_loaded_fixtures(object, load_instances = true)
-      all_loaded_fixtures.each_value do |fixture_set|
-        instantiate_fixtures(object, fixture_set, load_instances)
-      end
-    end
-
     cattr_accessor :all_loaded_fixtures, default: {}
 
     class ClassCache
@@ -504,14 +451,16 @@ module ActiveRecord
         @config      = config
 
         # Remove string values that aren't constants or subclasses of AR
-        @class_names.delete_if { |klass_name, klass| !insert_class(@class_names, klass_name, klass) }
+        @class_names.delete_if do |klass_name, klass|
+          !insert_class(@class_names, klass_name, klass)
+        end
       end
 
       def [](fs_name)
-        @class_names.fetch(fs_name) {
+        @class_names.fetch(fs_name) do
           klass = default_fixture_model(fs_name, @config).safe_constantize
           insert_class(@class_names, fs_name, klass)
-        }
+        end
       end
 
       private
@@ -530,38 +479,129 @@ module ActiveRecord
         end
     end
 
-    def self.create_fixtures(fixtures_directory, fixture_set_names, class_names = {}, config = ActiveRecord::Base)
-      fixture_set_names = Array(fixture_set_names).map(&:to_s)
-      class_names = ClassCache.new class_names, config
+    class << self
+      def default_fixture_model_name(fixture_set_name, config = ActiveRecord::Base) # :nodoc:
+        config.pluralize_table_names ?
+          fixture_set_name.singularize.camelize :
+          fixture_set_name.camelize
+      end
+
+      def default_fixture_table_name(fixture_set_name, config = ActiveRecord::Base) # :nodoc:
+        "#{ config.table_name_prefix }"\
+        "#{ fixture_set_name.tr('/', '_') }"\
+        "#{ config.table_name_suffix }".to_sym
+      end
+
+      def reset_cache
+        @@all_cached_fixtures.clear
+      end
 
-      # FIXME: Apparently JK uses this.
-      connection = block_given? ? yield : ActiveRecord::Base.connection
+      def cache_for_connection(connection)
+        @@all_cached_fixtures[connection]
+      end
 
-      files_to_read = fixture_set_names.reject { |fs_name|
-        fixture_is_cached?(connection, fs_name)
-      }
+      def fixture_is_cached?(connection, table_name)
+        cache_for_connection(connection)[table_name]
+      end
 
-      unless files_to_read.empty?
-        fixtures_map = {}
+      def cached_fixtures(connection, keys_to_fetch = nil)
+        if keys_to_fetch
+          cache_for_connection(connection).values_at(*keys_to_fetch)
+        else
+          cache_for_connection(connection).values
+        end
+      end
+
+      def cache_fixtures(connection, fixtures_map)
+        cache_for_connection(connection).update(fixtures_map)
+      end
+
+      def instantiate_fixtures(object, fixture_set, load_instances = true)
+        return unless load_instances
+        fixture_set.each do |fixture_name, fixture|
+          begin
+            object.instance_variable_set "@#{fixture_name}", fixture.find
+          rescue FixtureClassNotFound
+            nil
+          end
+        end
+      end
+
+      def instantiate_all_loaded_fixtures(object, load_instances = true)
+        all_loaded_fixtures.each_value do |fixture_set|
+          instantiate_fixtures(object, fixture_set, load_instances)
+        end
+      end
+
+      def create_fixtures(fixtures_directory, fixture_set_names, class_names = {}, config = ActiveRecord::Base)
+        fixture_set_names = Array(fixture_set_names).map(&:to_s)
+        class_names = ClassCache.new class_names, config
+
+        # FIXME: Apparently JK uses this.
+        connection = block_given? ? yield : ActiveRecord::Base.connection
+
+        fixture_files_to_read = fixture_set_names.reject do |fs_name|
+          fixture_is_cached?(connection, fs_name)
+        end
+
+        if fixture_files_to_read.any?
+          fixtures_map = read_and_insert(
+            fixtures_directory,
+            fixture_files_to_read,
+            class_names,
+            connection,
+          )
+          cache_fixtures(connection, fixtures_map)
+        end
+        cached_fixtures(connection, fixture_set_names)
+      end
+
+      # Returns a consistent, platform-independent identifier for +label+.
+      # Integer identifiers are values less than 2^30. UUIDs are RFC 4122 version 5 SHA-1 hashes.
+      def identify(label, column_type = :integer)
+        if column_type == :uuid
+          Digest::UUID.uuid_v5(Digest::UUID::OID_NAMESPACE, label.to_s)
+        else
+          Zlib.crc32(label.to_s) % MAX_ID
+        end
+      end
 
-        fixture_sets = files_to_read.map do |fs_name|
-          klass = class_names[fs_name]
-          conn = klass ? klass.connection : connection
-          fixtures_map[fs_name] = new( # ActiveRecord::FixtureSet.new
+      # Superclass for the evaluation contexts used by ERB fixtures.
+      def context_class
+        @context_class ||= Class.new
+      end
+
+      private
+
+      def read_and_insert(fixtures_directory, fixture_files, class_names, connection) # :nodoc:
+        fixtures_map = {}
+        fixture_sets = fixture_files.map do |fixture_set_name|
+          klass = class_names[fixture_set_name]
+          conn = klass&.connection || connection
+          fixtures_map[fixture_set_name] = new( # ActiveRecord::FixtureSet.new
             conn,
-            fs_name,
+            fixture_set_name,
             klass,
-            ::File.join(fixtures_directory, fs_name))
+            ::File.join(fixtures_directory, fixture_set_name)
+          )
         end
+        update_all_loaded_fixtures(fixtures_map)
 
-        update_all_loaded_fixtures fixtures_map
-        fixture_sets_by_connection = fixture_sets.group_by { |fs| fs.model_class ? fs.model_class.connection : connection }
+        insert(fixture_sets, connection)
+
+        fixtures_map
+      end
+
+      def insert(fixture_sets, connection) # :nodoc:
+        fixture_sets_by_connection = fixture_sets.group_by do |fixture_set|
+          fixture_set.model_class&.connection || connection
+        end
 
         fixture_sets_by_connection.each do |conn, set|
           table_rows_for_connection = Hash.new { |h, k| h[k] = [] }
 
-          set.each do |fs|
-            fs.table_rows.each do |table, rows|
+          set.each do |fixture_set|
+            fixture_set.table_rows.each do |table, rows|
               table_rows_for_connection[table].unshift(*rows)
             end
           end
@@ -572,31 +612,13 @@ module ActiveRecord
             set.each { |fs| conn.reset_pk_sequence!(fs.table_name) }
           end
         end
-
-        cache_fixtures(connection, fixtures_map)
       end
-      cached_fixtures(connection, fixture_set_names)
-    end
 
-    # Returns a consistent, platform-independent identifier for +label+.
-    # Integer identifiers are values less than 2^30. UUIDs are RFC 4122 version 5 SHA-1 hashes.
-    def self.identify(label, column_type = :integer)
-      if column_type == :uuid
-        Digest::UUID.uuid_v5(Digest::UUID::OID_NAMESPACE, label.to_s)
-      else
-        Zlib.crc32(label.to_s) % MAX_ID
+      def update_all_loaded_fixtures(fixtures_map) # :nodoc:
+        all_loaded_fixtures.update(fixtures_map)
       end
     end
 
-    # Superclass for the evaluation contexts used by ERB fixtures.
-    def self.context_class
-      @context_class ||= Class.new
-    end
-
-    def self.update_all_loaded_fixtures(fixtures_map) # :nodoc:
-      all_loaded_fixtures.update(fixtures_map)
-    end
-
     attr_reader :table_name, :name, :fixtures, :model_class, :config
 
     def initialize(connection, name, class_name, path, config = ActiveRecord::Base)
@@ -634,152 +656,18 @@ module ActiveRecord
     # Returns a hash of rows to be inserted. The key is the table, the value is
     # a list of rows to insert to that table.
     def table_rows
-      now = config.default_timezone == :utc ? Time.now.utc : Time.now
-
       # allow a standard key to be used for doing defaults in YAML
       fixtures.delete("DEFAULTS")
 
-      # track any join tables we need to insert later
-      rows = Hash.new { |h, table| h[table] = [] }
-
-      rows[table_name] = fixtures.map do |label, fixture|
-        row = fixture.to_hash
-
-        if model_class
-          # fill in timestamp columns if they aren't specified and the model is set to record_timestamps
-          if model_class.record_timestamps
-            timestamp_column_names.each do |c_name|
-              row[c_name] = now unless row.key?(c_name)
-            end
-          end
-
-          # interpolate the fixture label
-          row.each do |key, value|
-            row[key] = value.gsub("$LABEL", label.to_s) if value.is_a?(String)
-          end
-
-          # generate a primary key if necessary
-          if has_primary_key_column? && !row.include?(primary_key_name)
-            row[primary_key_name] = ActiveRecord::FixtureSet.identify(label, primary_key_type)
-          end
-
-          # Resolve enums
-          model_class.defined_enums.each do |name, values|
-            if row.include?(name)
-              row[name] = values.fetch(row[name], row[name])
-            end
-          end
-
-          # If STI is used, find the correct subclass for association reflection
-          reflection_class =
-            if row.include?(inheritance_column_name)
-              row[inheritance_column_name].constantize rescue model_class
-            else
-              model_class
-            end
-
-          reflection_class._reflections.each_value do |association|
-            case association.macro
-            when :belongs_to
-              # Do not replace association name with association foreign key if they are named the same
-              fk_name = (association.options[:foreign_key] || "#{association.name}_id").to_s
-
-              if association.name.to_s != fk_name && value = row.delete(association.name.to_s)
-                if association.polymorphic? && value.sub!(/\s*\(([^\)]*)\)\s*$/, "")
-                  # support polymorphic belongs_to as "label (Type)"
-                  row[association.foreign_type] = $1
-                end
-
-                fk_type = reflection_class.type_for_attribute(fk_name).type
-                row[fk_name] = ActiveRecord::FixtureSet.identify(value, fk_type)
-              end
-            when :has_many
-              if association.options[:through]
-                add_join_records(rows, row, HasManyThroughProxy.new(association))
-              end
-            end
-          end
-        end
-
-        row
-      end
-      rows
-    end
-
-    class ReflectionProxy # :nodoc:
-      def initialize(association)
-        @association = association
-      end
-
-      def join_table
-        @association.join_table
-      end
-
-      def name
-        @association.name
-      end
-
-      def primary_key_type
-        @association.klass.type_for_attribute(@association.klass.primary_key).type
-      end
-    end
-
-    class HasManyThroughProxy < ReflectionProxy # :nodoc:
-      def rhs_key
-        @association.foreign_key
-      end
-
-      def lhs_key
-        @association.through_reflection.foreign_key
-      end
-
-      def join_table
-        @association.through_reflection.table_name
-      end
+      TableRows.new(
+        table_name,
+        model_class: model_class,
+        fixtures: fixtures,
+        config: config,
+      ).to_hash
     end
 
     private
-      def primary_key_name
-        @primary_key_name ||= model_class && model_class.primary_key
-      end
-
-      def primary_key_type
-        @primary_key_type ||= model_class && model_class.type_for_attribute(model_class.primary_key).type
-      end
-
-      def add_join_records(rows, row, association)
-        # This is the case when the join table has no fixtures file
-        if (targets = row.delete(association.name.to_s))
-          table_name  = association.join_table
-          column_type = association.primary_key_type
-          lhs_key     = association.lhs_key
-          rhs_key     = association.rhs_key
-
-          targets = targets.is_a?(Array) ? targets : targets.split(/\s*,\s*/)
-          rows[table_name].concat targets.map { |target|
-            { lhs_key => row[primary_key_name],
-              rhs_key => ActiveRecord::FixtureSet.identify(target, column_type) }
-          }
-        end
-      end
-
-      def has_primary_key_column?
-        @has_primary_key_column ||= primary_key_name &&
-          model_class.columns.any? { |c| c.name == primary_key_name }
-      end
-
-      def timestamp_column_names
-        @timestamp_column_names ||=
-          %w(created_at created_on updated_at updated_on) & column_names
-      end
-
-      def inheritance_column_name
-        @inheritance_column_name ||= model_class && model_class.inheritance_column
-      end
-
-      def column_names
-        @column_names ||= @connection.columns(@table_name).collect(&:name)
-      end
 
       def model_class=(class_name)
         if class_name.is_a?(Class) # TODO: Should be an AR::Base type class, or any?
@@ -843,12 +731,9 @@ module ActiveRecord
     alias :to_hash :fixture
 
     def find
-      if model_class
-        model_class.unscoped do
-          model_class.find(fixture[model_class.primary_key])
-        end
-      else
-        raise FixtureClassNotFound, "No class attached to find."
+      raise FixtureClassNotFound, "No class attached to find." unless model_class
+      model_class.unscoped do
+        model_class.find(fixture[model_class.primary_key])
       end
     end
   end