Connect to multiple databases in test suite

This commit is the first step towards adding support for multiple
databases. It uses transient_record 2.0, which adds support for
multiple databases, and converts the test suite to it.

Multi-database support is going to be added to detectors in subsequent
commits.

active_record_doctor.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "pg", "~> 1.1.4"
   s.add_development_dependency "railties", ACTIVE_RECORD_SPEC
   s.add_development_dependency "rake", "~> 12.3.3"
-  s.add_development_dependency "transient_record", "= 1.0.0.rc1"
+  s.add_development_dependency "transient_record", "= 2.0.0.rc2"
 
   # We don't install rubocop in CI because we test against older Rubies that
   # are incompatible with Rubocop.

lib/active_record_doctor/utils.rb

@@ -13,8 +13,8 @@ def mysql?(connection = ActiveRecord::Base.connection)
 
       def expression_indexes_unsupported?(connection = ActiveRecord::Base.connection)
         (ActiveRecord::VERSION::STRING < "5.0") ||
-          # Active Record < 6 is unable to correctly parse expression indexes for MySQL.
-          (mysql?(connection) && ActiveRecord::VERSION::STRING < "6.0")
+          # Active Record is unable to correctly parse expression indexes for MySQL.
+          (mysql?(connection) && ActiveRecord::VERSION::STRING < "7.1")
       end
     end
   end

test/active_record_doctor/detectors/disable_test.rb

@@ -4,7 +4,7 @@ class ActiveRecordDoctor::Detectors::DisableTest < Minitest::Test
   # Disabling detectors is implemented in the base class. It's enought to test
   # it on a single detector to be reasonably certain it works on all of them.
   def test_disabling
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :name, null: true
     end.define_model do
       validates :name, presence: true

test/active_record_doctor/detectors/extraneous_indexes_test.rb

@@ -2,7 +2,7 @@
 
 class ActiveRecordDoctor::Detectors::ExtraneousIndexesTest < Minitest::Test
   def test_index_on_primary_key_is_duplicate
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
     end
 
@@ -14,7 +14,7 @@ def test_index_on_primary_key_is_duplicate
   def test_partial_index_on_primary_key
     skip("MySQL doesn't support partial indexes") if mysql?
 
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :admin
       t.index :id, where: "admin"
     end
@@ -23,7 +23,7 @@ def test_partial_index_on_primary_key
   end
 
   def test_index_on_non_standard_primary_key
-    create_table(:profiles, primary_key: :user_id) do |t|
+    Context.create_table(:profiles, primary_key: :user_id) do |t|
       t.index :user_id
     end
 
@@ -33,7 +33,7 @@ def test_index_on_non_standard_primary_key
   end
 
   def test_non_unique_version_of_index_is_duplicate
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :email
       t.index :email, unique: true, name: "unique_index_on_users_email"
     end
@@ -47,7 +47,7 @@ def test_non_unique_version_of_index_is_duplicate
   end
 
   def test_single_column_covered_by_unique_and_non_unique_multi_column_is_duplicate
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :last_name
       t.string :email
@@ -64,7 +64,7 @@ def test_single_column_covered_by_unique_and_non_unique_multi_column_is_duplicat
   end
 
   def test_multi_column_covered_by_unique_and_non_unique_multi_column_is_duplicate
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :last_name
       t.string :email
@@ -83,7 +83,7 @@ def test_multi_column_covered_by_unique_and_non_unique_multi_column_is_duplicate
   end
 
   def test_unique_index_with_fewer_columns
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :last_name
       t.index :first_name, unique: true
@@ -98,7 +98,7 @@ def test_unique_index_with_fewer_columns
   def test_expression_index_not_covered_by_multicolumn_index
     skip("Expression indexes are not supported") if ActiveRecordDoctor::Utils.expression_indexes_unsupported?
 
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :email
       t.index "(lower(email))"
@@ -111,7 +111,7 @@ def test_expression_index_not_covered_by_multicolumn_index
   def test_unique_expression_index_not_covered_by_unique_multicolumn_index
     skip("Expression indexes are not supported") if ActiveRecordDoctor::Utils.expression_indexes_unsupported?
 
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :email
       t.index "(lower(email))", unique: true
@@ -122,7 +122,7 @@ def test_unique_expression_index_not_covered_by_unique_multicolumn_index
   end
 
   def test_not_covered_by_different_index_type
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :last_name
       t.index [:last_name, :first_name], using: :btree
@@ -140,7 +140,7 @@ def test_not_covered_by_different_index_type
   def test_not_covered_by_partial_index
     skip("MySQL doesn't support partial indexes") if mysql?
 
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :last_name
       t.boolean :active
@@ -155,7 +155,7 @@ def test_not_covered_with_different_opclasses
     skip("ActiveRecord < 5.2 doesn't support operator classes") if ActiveRecord::VERSION::STRING < "5.2"
     skip("MySQL doesn't support operator classes") if mysql?
 
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :first_name
       t.string :last_name
       t.index [:last_name, :first_name], opclass: :varchar_pattern_ops
@@ -169,7 +169,7 @@ def test_single_column_covered_by_multi_column_on_materialized_view_is_duplicate
     skip("Only PostgreSQL supports materialized views") unless postgresql?
 
     begin
-      create_table(:users) do |t|
+      Context.create_table(:users) do |t|
         t.string :first_name
         t.string :last_name
         t.integer :age
@@ -197,7 +197,7 @@ def test_config_ignore_tables
     # ignore_tables into account. We trigger those errors by indexing the
     # primary key (the first extraneous index) and then indexing email twice
     # (index2... is the other extraneous index).
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
       t.string :email
 
@@ -216,7 +216,7 @@ def test_config_ignore_tables
   end
 
   def test_config_ignore_tables_regexp
-    create_table(:users_tmp) do |t|
+    Context.create_table(:users_tmp) do |t|
       t.index :id
     end
 
@@ -231,7 +231,7 @@ def test_config_ignore_tables_regexp
   end
 
   def test_config_ignore_tables_string_ignores_exact_match
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
     end
 
@@ -248,7 +248,7 @@ def test_config_ignore_tables_string_ignores_exact_match
   end
 
   def test_config_global_ignore_tables
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
       t.string :email
 
@@ -266,7 +266,7 @@ def test_config_global_ignore_tables
   end
 
   def test_config_global_ignore_indexes
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
       t.string :email
 
@@ -288,7 +288,7 @@ def test_config_global_ignore_indexes
   end
 
   def test_config_detector_ignore_indexes
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
       t.string :email
       t.string :api_key
@@ -308,7 +308,7 @@ def test_config_detector_ignore_indexes
   end
 
   def test_config_detector_ignore_indexes_regexp
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.index :id
       t.string :email
       t.string :api_key

test/active_record_doctor/detectors/incorrect_boolean_presence_validation_test.rb

@@ -2,7 +2,7 @@
 
 class ActiveRecordDoctor::Detectors::IncorrectBooleanPresenceValidationTest < Minitest::Test
   def test_presence_true_is_reported_on_boolean_only
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.string :email, null: false
       t.boolean :active, null: false
     end.define_model do
@@ -12,13 +12,20 @@ def test_presence_true_is_reported_on_boolean_only
       validates :email, :active, presence: true
     end
 
+    SecondaryContext.create_table(:subscriptions) do |t|
+      t.boolean :active, null: false
+    end.define_model do
+      validates :active, presence: true
+    end
+
     assert_problems(<<~OUTPUT)
-      replace the `presence` validator on TransientRecord::Models::User.active with `inclusion` - `presence` can't be used on booleans
+      replace the `presence` validator on Context::User.active with `inclusion` - `presence` can't be used on booleans
+      replace the `presence` validator on SecondaryContext::Subscription.active with `inclusion` - `presence` can't be used on booleans
     OUTPUT
   end
 
   def test_inclusion_is_not_reported
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :active, null: false
     end.define_model do
       validates :active, inclusion: { in: [true, false] }
@@ -28,13 +35,31 @@ def test_inclusion_is_not_reported
   end
 
   def test_models_with_non_existent_tables_are_skipped
-    define_model(:User)
+    Context.define_model(:User)
+
+    refute_problems
+  end
+
+  def test_config_ignore_databases
+    SecondaryContext.create_table(:users) do |t|
+      t.string :email, null: false
+      t.boolean :active, null: false
+    end.define_model do
+      validates :email, :active, presence: true
+    end
+
+    config_file(<<-CONFIG)
+      ActiveRecordDoctor.configure do |config|
+        config.detector :incorrect_boolean_presence_validation,
+          ignore_databases: [:secondary]
+      end
+    CONFIG
 
     refute_problems
   end
 
   def test_config_ignore_models
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :active, null: false
     end.define_model do
       validates :active, presence: true
@@ -43,15 +68,15 @@ def test_config_ignore_models
     config_file(<<-CONFIG)
       ActiveRecordDoctor.configure do |config|
         config.detector :incorrect_boolean_presence_validation,
-          ignore_models: ["TransientRecord::Models::User"]
+          ignore_models: ["Context::User"]
       end
     CONFIG
 
     refute_problems
   end
 
   def test_config_ignore_models_regexp
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :active, null: false
     end.define_model do
       validates :active, presence: true
@@ -68,23 +93,23 @@ def test_config_ignore_models_regexp
   end
 
   def test_global_ignore_models
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :active, null: false
     end.define_model do
       validates :active, presence: true
     end
 
     config_file(<<-CONFIG)
       ActiveRecordDoctor.configure do |config|
-        config.global :ignore_models, ["TransientRecord::Models::User"]
+        config.global :ignore_models, ["Context::User"]
       end
     CONFIG
 
     refute_problems
   end
 
   def test_config_ignore_attributes
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :active, null: false
     end.define_model do
       validates :active, presence: true
@@ -93,15 +118,15 @@ def test_config_ignore_attributes
     config_file(<<-CONFIG)
       ActiveRecordDoctor.configure do |config|
         config.detector :incorrect_boolean_presence_validation,
-          ignore_attributes: ["TransientRecord::Models::User.active"]
+          ignore_attributes: ["Context::User.active"]
       end
     CONFIG
 
     refute_problems
   end
 
   def test_config_ignore_attributes_regexp
-    create_table(:users) do |t|
+    Context.create_table(:users) do |t|
       t.boolean :active_old, null: false
     end.define_model do
       validates :active_old, presence: true