Merge pull request #12016 from roderickvd/uuid_fixes

Auto-generate stable fixture UUIDs on PostgreSQL

Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/fixtures.rb
	activerecord/test/cases/adapters/postgresql/uuid_test.rb
	activesupport/CHANGELOG.md

3 files changed, 80 insertions, 0 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index f65d9ea120..8f1eecf9fa 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Add `SecureRandom::uuid_v3` and `SecureRandom::uuid_v5` to support stable
+    UUID fixtures on PostgreSQL.
+
+    *Roderick van Domburg*
+
 *   `ActiveSupport::SafeBuffer#prepend` acts like `String#prepend` and modifies
     instance in-place, returning self. `ActiveSupport::SafeBuffer#prepend!` is
     deprecated.
diff --git a/activesupport/lib/active_support/core_ext/securerandom.rb b/activesupport/lib/active_support/core_ext/securerandom.rb
new file mode 100644
index 0000000000..fec8f7c0ec
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/securerandom.rb
@@ -0,0 +1,47 @@
+module SecureRandom
+  UUID_DNS_NAMESPACE  = "k\xA7\xB8\x10\x9D\xAD\x11\xD1\x80\xB4\x00\xC0O\xD40\xC8" #:nodoc:
+  UUID_URL_NAMESPACE  = "k\xA7\xB8\x11\x9D\xAD\x11\xD1\x80\xB4\x00\xC0O\xD40\xC8" #:nodoc:
+  UUID_OID_NAMESPACE  = "k\xA7\xB8\x12\x9D\xAD\x11\xD1\x80\xB4\x00\xC0O\xD40\xC8" #:nodoc:
+  UUID_X500_NAMESPACE = "k\xA7\xB8\x14\x9D\xAD\x11\xD1\x80\xB4\x00\xC0O\xD40\xC8" #:nodoc:
+  
+  # Generates a v5 non-random UUID (Universally Unique IDentifier).
+  #
+  # Using Digest::MD5 generates version 3 UUIDs; Digest::SHA1 generates version 5 UUIDs.
+  # ::uuid_from_hash always generates the same UUID for a given name and namespace combination.
+  #
+  # See RFC 4122 for details of UUID at: http://www.ietf.org/rfc/rfc4122.txt
+  def self.uuid_from_hash(hash_class, uuid_namespace, name)
+    if hash_class == Digest::MD5
+      version = 3
+    elsif hash_class == Digest::SHA1
+      version = 5
+    else
+      raise ArgumentError, "Expected Digest::SHA1 or Digest::MD5, got #{hash_class.name}."
+    end
+
+    hash = hash_class.new
+    hash.update(uuid_namespace)
+    hash.update(name)
+
+    ary = hash.digest.unpack('NnnnnN')
+    ary[2] = (ary[2] & 0x0FFF) | (version << 12)
+    ary[3] = (ary[3] & 0x3FFF) | 0x8000
+
+    "%08x-%04x-%04x-%04x-%04x%08x" % ary
+  end
+
+  # Convenience method for ::uuid_from_hash using Digest::MD5.
+  def self.uuid_v3(uuid_namespace, name)
+    self.uuid_from_hash(Digest::MD5, uuid_namespace, name)
+  end
+
+  # Convenience method for ::uuid_from_hash using Digest::SHA1.
+  def self.uuid_v5(uuid_namespace, name)
+    self.uuid_from_hash(Digest::SHA1, uuid_namespace, name)
+  end
+
+  class << self
+    # Alias for ::uuid.
+    alias_method :uuid_v4, :uuid
+  end
+end
diff --git a/activesupport/test/core_ext/securerandom_test.rb b/activesupport/test/core_ext/securerandom_test.rb
new file mode 100644
index 0000000000..71980f6910
--- /dev/null
+++ b/activesupport/test/core_ext/securerandom_test.rb
@@ -0,0 +1,28 @@
+require 'abstract_unit'
+require 'active_support/core_ext/securerandom'
+
+class SecureRandomExt < ActiveSupport::TestCase
+  def test_v3_uuids
+    assert_equal "3d813cbb-47fb-32ba-91df-831e1593ac29", SecureRandom.uuid_v3(SecureRandom::UUID_DNS_NAMESPACE, "www.widgets.com")
+    assert_equal "86df55fb-428e-3843-8583-ba3c05f290bc", SecureRandom.uuid_v3(SecureRandom::UUID_URL_NAMESPACE, "http://www.widgets.com")
+    assert_equal "8c29ab0e-a2dc-3482-b5eb-20cb2e2387a1", SecureRandom.uuid_v3(SecureRandom::UUID_OID_NAMESPACE, "1.2.3")
+    assert_equal "ee49149d-53a4-304a-890b-468229f6afc3", SecureRandom.uuid_v3(SecureRandom::UUID_X500_NAMESPACE, "cn=John Doe, ou=People, o=Acme, Inc., c=US")
+  end
+
+  def test_v5_uuids
+    assert_equal "21f7f8de-8051-5b89-8680-0195ef798b6a", SecureRandom.uuid_v5(SecureRandom::UUID_DNS_NAMESPACE, "www.widgets.com")
+    assert_equal "4e570fd8-186d-5a74-90f0-4d28e34673a1", SecureRandom.uuid_v5(SecureRandom::UUID_URL_NAMESPACE, "http://www.widgets.com")
+    assert_equal "42d5e23b-3a02-5135-85c6-52d1102f1f00", SecureRandom.uuid_v5(SecureRandom::UUID_OID_NAMESPACE, "1.2.3")
+    assert_equal "fd5b2ddf-bcfe-58b6-90d6-db50f74db527", SecureRandom.uuid_v5(SecureRandom::UUID_X500_NAMESPACE, "cn=John Doe, ou=People, o=Acme, Inc., c=US")
+  end
+
+  def test_uuid_v4_alias
+    assert_equal SecureRandom.method(:uuid_v4), SecureRandom.method(:uuid)
+  end
+
+  def test_invalid_hash_class
+    assert_raise ArgumentError do
+      SecureRandom.uuid_from_hash(Digest::SHA2, SecureRandom::UUID_OID_NAMESPACE, '1.2.3')
+    end
+  end
+end