Checks :algorithm argument for valid values

4 files changed, 18 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 35f1112798..d5ae4058ed 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -757,7 +757,13 @@ module ActiveRecord
             index_type = options[:unique] ? "UNIQUE" : ""
             index_name = options[:name].to_s if options.key?(:name)
             max_index_length = options.fetch(:internal, false) ? index_name_length : allowed_index_name_length
-            algorithm = index_algorithms[options[:algorithm]]
+
+            if index_algorithms.key?(options[:algorithm])
+              algorithm = index_algorithms[options[:algorithm]]
+            elsif options[:algorithm].present?
+              raise ArgumentError.new("Algorithm must be one of the following: #{index_algorithms.keys.map(&:inspect).join(', ')}")
+            end
+
             using = "USING #{options[:using]}" if options[:using].present?
 
             if supports_partial_index?
diff --git a/activerecord/test/cases/adapters/mysql/active_schema_test.rb b/activerecord/test/cases/adapters/mysql/active_schema_test.rb
index ca6478f6ac..9050ae3fe3 100644
--- a/activerecord/test/cases/adapters/mysql/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql/active_schema_test.rb
@@ -47,6 +47,10 @@ class ActiveSchemaTest < ActiveRecord::TestCase
     expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10)) ALGORITHM = COPY"
     assert_equal expected, add_index(:people, :last_name, :length => 10, using: :btree, algorithm: :copy)
 
+    assert_raise ArgumentError do
+      add_index(:people, :last_name, algorithm: :coyp)
+    end
+
     expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` USING btree ON `people` (`last_name`(15), `first_name`(15)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => 15, :using => :btree)
 
diff --git a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
index 9b10d23465..48d63aeef5 100644
--- a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
@@ -47,6 +47,10 @@ class ActiveSchemaTest < ActiveRecord::TestCase
     expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10)) ALGORITHM = COPY"
     assert_equal expected, add_index(:people, :last_name, :length => 10, using: :btree, algorithm: :copy)
 
+    assert_raise ArgumentError do
+      add_index(:people, :last_name, algorithm: :coyp)
+    end
+
     expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` USING btree ON `people` (`last_name`(15), `first_name`(15)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => 15, :using => :btree)
 
diff --git a/activerecord/test/cases/adapters/postgresql/active_schema_test.rb b/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
index 41e9bb912e..16329689c0 100644
--- a/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
@@ -43,6 +43,9 @@ class PostgresqlActiveSchemaTest < ActiveRecord::TestCase
       assert_equal expected, add_index(:people, :last_name, using: type, algorithm: :concurrently)
     end
 
+    assert_raise ArgumentError do
+      add_index(:people, :last_name, algorithm: :copy)
+    end
     expected = %(CREATE UNIQUE INDEX  "index_people_on_last_name" ON "people" USING gist ("last_name"))
     assert_equal expected, add_index(:people, :last_name, :unique => true, :using => :gist)