1 files changed, 92 insertions, 0 deletions
diff --git a/utils/ipc/mojo/public/tools/mojom/enum_unittest.py b/utils/ipc/mojo/public/tools/mojom/enum_unittest.py
new file mode 100644
index 00000000..d9005078
--- /dev/null
+++ b/utils/ipc/mojo/public/tools/mojom/enum_unittest.py
@@ -0,0 +1,92 @@
+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+from mojom_parser_test_case import MojomParserTestCase
+
+
+class EnumTest(MojomParserTestCase):
+  """Tests enum parsing behavior."""
+
+  def testExplicitValues(self):
+    """Verifies basic parsing of assigned integral values."""
+    types = self.ExtractTypes('enum E { kFoo=0, kBar=2, kBaz };')
+    self.assertEqual('kFoo', types['E'].fields[0].mojom_name)
+    self.assertEqual(0, types['E'].fields[0].numeric_value)
+    self.assertEqual('kBar', types['E'].fields[1].mojom_name)
+    self.assertEqual(2, types['E'].fields[1].numeric_value)
+    self.assertEqual('kBaz', types['E'].fields[2].mojom_name)
+    self.assertEqual(3, types['E'].fields[2].numeric_value)
+
+  def testImplicitValues(self):
+    """Verifies basic automatic assignment of integral values at parse time."""
+    types = self.ExtractTypes('enum E { kFoo, kBar, kBaz };')
+    self.assertEqual('kFoo', types['E'].fields[0].mojom_name)
+    self.assertEqual(0, types['E'].fields[0].numeric_value)
+    self.assertEqual('kBar', types['E'].fields[1].mojom_name)
+    self.assertEqual(1, types['E'].fields[1].numeric_value)
+    self.assertEqual('kBaz', types['E'].fields[2].mojom_name)
+    self.assertEqual(2, types['E'].fields[2].numeric_value)
+
+  def testSameEnumReference(self):
+    """Verifies that an enum value can be assigned from the value of another
+    field within the same enum."""
+    types = self.ExtractTypes('enum E { kA, kB, kFirst=kA };')
+    self.assertEqual('kA', types['E'].fields[0].mojom_name)
+    self.assertEqual(0, types['E'].fields[0].numeric_value)
+    self.assertEqual('kB', types['E'].fields[1].mojom_name)
+    self.assertEqual(1, types['E'].fields[1].numeric_value)
+    self.assertEqual('kFirst', types['E'].fields[2].mojom_name)
+    self.assertEqual(0, types['E'].fields[2].numeric_value)
+
+  def testSameModuleOtherEnumReference(self):
+    """Verifies that an enum value can be assigned from the value of a field
+    in another enum within the same module."""
+    types = self.ExtractTypes('enum E { kA, kB }; enum F { kA = E.kB };')
+    self.assertEqual(1, types['F'].fields[0].numeric_value)
+
+  def testImportedEnumReference(self):
+    """Verifies that an enum value can be assigned from the value of a field
+    in another enum within a different module."""
+    a_mojom = 'a.mojom'
+    self.WriteFile(a_mojom, 'module a; enum E { kFoo=42, kBar };')
+    b_mojom = 'b.mojom'
+    self.WriteFile(b_mojom,
+                   'module b; import "a.mojom"; enum F { kFoo = a.E.kBar };')
+    self.ParseMojoms([a_mojom, b_mojom])
+    b = self.LoadModule(b_mojom)
+
+    self.assertEqual('F', b.enums[0].mojom_name)
+    self.assertEqual('kFoo', b.enums[0].fields[0].mojom_name)
+    self.assertEqual(43, b.enums[0].fields[0].numeric_value)
+
+  def testConstantReference(self):
+    """Verifies that an enum value can be assigned from the value of an
+    integral constant within the same module."""
+    types = self.ExtractTypes('const int32 kFoo = 42; enum E { kA = kFoo };')
+    self.assertEqual(42, types['E'].fields[0].numeric_value)
+
+  def testInvalidConstantReference(self):
+    """Verifies that enum values cannot be assigned from the value of
+    non-integral constants."""
+    with self.assertRaisesRegexp(ValueError, 'not an integer'):
+      self.ExtractTypes('const float kFoo = 1.0; enum E { kA = kFoo };')
+    with self.assertRaisesRegexp(ValueError, 'not an integer'):
+      self.ExtractTypes('const double kFoo = 1.0; enum E { kA = kFoo };')
+    with self.assertRaisesRegexp(ValueError, 'not an integer'):
+      self.ExtractTypes('const string kFoo = "lol"; enum E { kA = kFoo };')
+
+  def testImportedConstantReference(self):
+    """Verifies that an enum value can be assigned from the value of an integral
+    constant within an imported module."""
+    a_mojom = 'a.mojom'
+    self.WriteFile(a_mojom, 'module a; const int32 kFoo = 37;')
+    b_mojom = 'b.mojom'
+    self.WriteFile(b_mojom,
+                   'module b; import "a.mojom"; enum F { kFoo = a.kFoo };')
+    self.ParseMojoms([a_mojom, b_mojom])
+    b = self.LoadModule(b_mojom)
+
+    self.assertEqual('F', b.enums[0].mojom_name)
+    self.assertEqual('kFoo', b.enums[0].fields[0].mojom_name)
+    self.assertEqual(37, b.enums[0].fields[0].numeric_value)