releasetools: Add a BuildInfo class.

Prior to this CL, we have similar codes in different paths
(WriteFullOTAPackage / WriteBlockIncrementalOTAPackage /
WriteABOTAPackageWithBrilloScript). This CL factors out the common codes
that deal with OEM-specific properties into BuildInfo class, and adds
tests for the new class.

Test: python -m unittest test_ota_from_target_files
Test: Create an incremental package that uses and doesn't use OEM
      properties respectively.
Test: Create a full package that uses and doesn't use OEM properties
      respectively.
Change-Id: Ida914cace12803d55396fa503bafcac2db2a520e
diff --git a/tools/releasetools/test_ota_from_target_files.py b/tools/releasetools/test_ota_from_target_files.py
new file mode 100644
index 0000000..0948c61
--- /dev/null
+++ b/tools/releasetools/test_ota_from_target_files.py
@@ -0,0 +1,302 @@
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import copy
+import unittest
+
+import common
+from ota_from_target_files import (
+    _LoadOemDicts, BuildInfo, WriteFingerprintAssertion)
+
+
+class MockScriptWriter(object):
+  """A class that mocks edify_generator.EdifyGenerator.
+
+  It simply pushes the incoming arguments onto script stack, which is to assert
+  the calls to EdifyGenerator functions.
+  """
+
+  def __init__(self):
+    self.script = []
+
+  def Mount(self, *args):
+    self.script.append(('Mount',) + args)
+
+  def AssertDevice(self, *args):
+    self.script.append(('AssertDevice',) + args)
+
+  def AssertOemProperty(self, *args):
+    self.script.append(('AssertOemProperty',) + args)
+
+  def AssertFingerprintOrThumbprint(self, *args):
+    self.script.append(('AssertFingerprintOrThumbprint',) + args)
+
+  def AssertSomeFingerprint(self, *args):
+    self.script.append(('AssertSomeFingerprint',) + args)
+
+  def AssertSomeThumbprint(self, *args):
+    self.script.append(('AssertSomeThumbprint',) + args)
+
+
+class BuildInfoTest(unittest.TestCase):
+
+  TEST_INFO_DICT = {
+      'build.prop' : {
+          'ro.product.device' : 'product-device',
+          'ro.product.name' : 'product-name',
+          'ro.build.fingerprint' : 'build-fingerprint',
+          'ro.build.foo' : 'build-foo',
+      },
+      'vendor.build.prop' : {
+          'ro.vendor.build.fingerprint' : 'vendor-build-fingerprint',
+      },
+      'property1' : 'value1',
+      'property2' : 4096,
+  }
+
+  TEST_INFO_DICT_USES_OEM_PROPS = {
+      'build.prop' : {
+          'ro.product.name' : 'product-name',
+          'ro.build.thumbprint' : 'build-thumbprint',
+          'ro.build.bar' : 'build-bar',
+      },
+      'vendor.build.prop' : {
+          'ro.vendor.build.fingerprint' : 'vendor-build-fingerprint',
+      },
+      'property1' : 'value1',
+      'property2' : 4096,
+      'oem_fingerprint_properties' : 'ro.product.device ro.product.brand',
+  }
+
+  TEST_OEM_DICTS = [
+      {
+          'ro.product.brand' : 'brand1',
+          'ro.product.device' : 'device1',
+      },
+      {
+          'ro.product.brand' : 'brand2',
+          'ro.product.device' : 'device2',
+      },
+      {
+          'ro.product.brand' : 'brand3',
+          'ro.product.device' : 'device3',
+      },
+  ]
+
+  def test_init(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    self.assertEqual('product-device', target_info.device)
+    self.assertEqual('build-fingerprint', target_info.fingerprint)
+    self.assertFalse(target_info.is_ab)
+    self.assertIsNone(target_info.oem_props)
+
+  def test_init_with_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    self.assertEqual('device1', target_info.device)
+    self.assertEqual('brand1/product-name/device1:build-thumbprint',
+                     target_info.fingerprint)
+
+    # Swap the order in oem_dicts, which would lead to different BuildInfo.
+    oem_dicts = copy.copy(self.TEST_OEM_DICTS)
+    oem_dicts[0], oem_dicts[2] = oem_dicts[2], oem_dicts[0]
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS, oem_dicts)
+    self.assertEqual('device3', target_info.device)
+    self.assertEqual('brand3/product-name/device3:build-thumbprint',
+                     target_info.fingerprint)
+
+    # Missing oem_dict should be rejected.
+    self.assertRaises(AssertionError, BuildInfo,
+                      self.TEST_INFO_DICT_USES_OEM_PROPS, None)
+
+  def test___getitem__(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    self.assertEqual('value1', target_info['property1'])
+    self.assertEqual(4096, target_info['property2'])
+    self.assertEqual('build-foo', target_info['build.prop']['ro.build.foo'])
+
+  def test___getitem__with_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    self.assertEqual('value1', target_info['property1'])
+    self.assertEqual(4096, target_info['property2'])
+    self.assertRaises(KeyError,
+                      lambda: target_info['build.prop']['ro.build.foo'])
+
+  def test_get(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    self.assertEqual('value1', target_info.get('property1'))
+    self.assertEqual(4096, target_info.get('property2'))
+    self.assertEqual(4096, target_info.get('property2', 1024))
+    self.assertEqual(1024, target_info.get('property-nonexistent', 1024))
+    self.assertEqual('build-foo', target_info.get('build.prop')['ro.build.foo'])
+
+  def test_get_with_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    self.assertEqual('value1', target_info.get('property1'))
+    self.assertEqual(4096, target_info.get('property2'))
+    self.assertEqual(4096, target_info.get('property2', 1024))
+    self.assertEqual(1024, target_info.get('property-nonexistent', 1024))
+    self.assertIsNone(target_info.get('build.prop').get('ro.build.foo'))
+    self.assertRaises(KeyError,
+                      lambda: target_info.get('build.prop')['ro.build.foo'])
+
+  def test_GetBuildProp(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    self.assertEqual('build-foo', target_info.GetBuildProp('ro.build.foo'))
+    self.assertRaises(common.ExternalError, target_info.GetBuildProp,
+                      'ro.build.nonexistent')
+
+  def test_GetBuildProp_with_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    self.assertEqual('build-bar', target_info.GetBuildProp('ro.build.bar'))
+    self.assertRaises(common.ExternalError, target_info.GetBuildProp,
+                      'ro.build.nonexistent')
+
+  def test_GetVendorBuildProp(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    self.assertEqual('vendor-build-fingerprint',
+                     target_info.GetVendorBuildProp(
+                         'ro.vendor.build.fingerprint'))
+    self.assertRaises(common.ExternalError, target_info.GetVendorBuildProp,
+                      'ro.build.nonexistent')
+
+  def test_GetVendorBuildProp_with_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    self.assertEqual('vendor-build-fingerprint',
+                     target_info.GetVendorBuildProp(
+                         'ro.vendor.build.fingerprint'))
+    self.assertRaises(common.ExternalError, target_info.GetVendorBuildProp,
+                      'ro.build.nonexistent')
+
+  def test_WriteMountOemScript(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    script_writer = MockScriptWriter()
+    target_info.WriteMountOemScript(script_writer)
+    self.assertEqual([('Mount', '/oem', None)], script_writer.script)
+
+  def test_WriteDeviceAssertions(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    script_writer = MockScriptWriter()
+    target_info.WriteDeviceAssertions(script_writer, False)
+    self.assertEqual([('AssertDevice', 'product-device')], script_writer.script)
+
+  def test_WriteDeviceAssertions_with_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    script_writer = MockScriptWriter()
+    target_info.WriteDeviceAssertions(script_writer, False)
+    self.assertEqual(
+        [
+            ('AssertOemProperty', 'ro.product.device',
+             ['device1', 'device2', 'device3'], False),
+            ('AssertOemProperty', 'ro.product.brand',
+             ['brand1', 'brand2', 'brand3'], False),
+        ],
+        script_writer.script)
+
+  def test_WriteFingerprintAssertion_without_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    source_info_dict = copy.deepcopy(self.TEST_INFO_DICT)
+    source_info_dict['build.prop']['ro.build.fingerprint'] = (
+        'source-build-fingerprint')
+    source_info = BuildInfo(source_info_dict, None)
+
+    script_writer = MockScriptWriter()
+    WriteFingerprintAssertion(script_writer, target_info, source_info)
+    self.assertEqual(
+        [('AssertSomeFingerprint', 'source-build-fingerprint',
+          'build-fingerprint')],
+        script_writer.script)
+
+  def test_WriteFingerprintAssertion_with_source_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    source_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+
+    script_writer = MockScriptWriter()
+    WriteFingerprintAssertion(script_writer, target_info, source_info)
+    self.assertEqual(
+        [('AssertFingerprintOrThumbprint', 'build-fingerprint',
+          'build-thumbprint')],
+        script_writer.script)
+
+  def test_WriteFingerprintAssertion_with_target_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    source_info = BuildInfo(self.TEST_INFO_DICT, None)
+
+    script_writer = MockScriptWriter()
+    WriteFingerprintAssertion(script_writer, target_info, source_info)
+    self.assertEqual(
+        [('AssertFingerprintOrThumbprint', 'build-fingerprint',
+          'build-thumbprint')],
+        script_writer.script)
+
+  def test_WriteFingerprintAssertion_with_both_oem_props(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT_USES_OEM_PROPS,
+                            self.TEST_OEM_DICTS)
+    source_info_dict = copy.deepcopy(self.TEST_INFO_DICT_USES_OEM_PROPS)
+    source_info_dict['build.prop']['ro.build.thumbprint'] = (
+        'source-build-thumbprint')
+    source_info = BuildInfo(source_info_dict, self.TEST_OEM_DICTS)
+
+    script_writer = MockScriptWriter()
+    WriteFingerprintAssertion(script_writer, target_info, source_info)
+    self.assertEqual(
+        [('AssertSomeThumbprint', 'build-thumbprint',
+          'source-build-thumbprint')],
+        script_writer.script)
+
+
+class LoadOemDictsTest(unittest.TestCase):
+
+  def tearDown(self):
+    common.Cleanup()
+
+  def test_NoneDict(self):
+    self.assertIsNone(_LoadOemDicts(None))
+
+  def test_SingleDict(self):
+    dict_file = common.MakeTempFile()
+    with open(dict_file, 'w') as dict_fp:
+      dict_fp.write('abc=1\ndef=2\nxyz=foo\na.b.c=bar\n')
+
+    oem_dicts = _LoadOemDicts([dict_file])
+    self.assertEqual(1, len(oem_dicts))
+    self.assertEqual('foo', oem_dicts[0]['xyz'])
+    self.assertEqual('bar', oem_dicts[0]['a.b.c'])
+
+  def test_MultipleDicts(self):
+    oem_source = []
+    for i in range(3):
+      dict_file = common.MakeTempFile()
+      with open(dict_file, 'w') as dict_fp:
+        dict_fp.write(
+            'ro.build.index={}\ndef=2\nxyz=foo\na.b.c=bar\n'.format(i))
+      oem_source.append(dict_file)
+
+    oem_dicts = _LoadOemDicts(oem_source)
+    self.assertEqual(3, len(oem_dicts))
+    for i, oem_dict in enumerate(oem_dicts):
+      self.assertEqual('2', oem_dict['def'])
+      self.assertEqual('foo', oem_dict['xyz'])
+      self.assertEqual('bar', oem_dict['a.b.c'])
+      self.assertEqual('{}'.format(i), oem_dict['ro.build.index'])