1 files changed, 83 insertions, 4 deletions
diff --git a/utils/ipc/mojo/public/tools/mojom/check_stable_mojom_compatibility_unittest.py b/utils/ipc/mojo/public/tools/mojom/check_stable_mojom_compatibility_unittest.py
index 9f51ea77..06769c95 100755
--- a/utils/ipc/mojo/public/tools/mojom/check_stable_mojom_compatibility_unittest.py
+++ b/utils/ipc/mojo/public/tools/mojom/check_stable_mojom_compatibility_unittest.py
@@ -1,5 +1,5 @@
-#!/usr/bin/env python
-# Copyright 2020 The Chromium Authors. All rights reserved.
+#!/usr/bin/env python3
+# Copyright 2020 The Chromium Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -15,7 +15,7 @@ import check_stable_mojom_compatibility
 from mojom.generate import module
 
 
-class Change(object):
+class Change:
   """Helper to clearly define a mojom file delta to be analyzed."""
 
   def __init__(self, filename, old=None, new=None):
@@ -28,7 +28,7 @@ class Change(object):
 
 class UnchangedFile(Change):
   def __init__(self, filename, contents):
-    super(UnchangedFile, self).__init__(filename, old=contents, new=contents)
+    super().__init__(filename, old=contents, new=contents)
 
 
 class CheckStableMojomCompatibilityTest(unittest.TestCase):
@@ -258,3 +258,82 @@ class CheckStableMojomCompatibilityTest(unittest.TestCase):
                [Stable] struct T { foo.S s; int32 x; };
                """)
     ])
+
+  def testWithPartialImport(self):
+    """The compatibility checking tool correctly parses imports with partial
+    paths."""
+    self.assertBackwardCompatible([
+        UnchangedFile('foo/foo.mojom', 'module foo; [Stable] struct S {};'),
+        Change('foo/bar.mojom',
+               old="""\
+               module bar;
+               import "foo/foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """,
+               new="""\
+               module bar;
+               import "foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """)
+    ])
+
+    self.assertBackwardCompatible([
+        UnchangedFile('foo/foo.mojom', 'module foo; [Stable] struct S {};'),
+        Change('foo/bar.mojom',
+               old="""\
+               module bar;
+               import "foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """,
+               new="""\
+               module bar;
+               import "foo/foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """)
+    ])
+
+    self.assertNotBackwardCompatible([
+        UnchangedFile('foo/foo.mojom', 'module foo; [Stable] struct S {};'),
+        Change('bar/bar.mojom',
+               old="""\
+               module bar;
+               import "foo/foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """,
+               new="""\
+               module bar;
+               import "foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """)
+    ])
+
+    self.assertNotBackwardCompatible([
+        UnchangedFile('foo/foo.mojom', 'module foo; [Stable] struct S {};'),
+        Change('bar/bar.mojom',
+               old="""\
+               module bar;
+               import "foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """,
+               new="""\
+               module bar;
+               import "foo/foo.mojom";
+               [Stable] struct T { foo.S s; };
+               """)
+    ])
+
+  def testNewEnumDefault(self):
+    # Should be backwards compatible since it does not affect the wire format.
+    # This specific case also checks that the backwards compatibility checker
+    # does not throw an error due to the older version of the enum not
+    # specifying [Default].
+    self.assertBackwardCompatible([
+        Change('foo/foo.mojom',
+               old='[Extensible] enum E { One };',
+               new='[Extensible] enum E { [Default] One };')
+    ])
+    self.assertBackwardCompatible([
+        Change('foo/foo.mojom',
+               old='[Extensible] enum E { [Default] One, Two, };',
+               new='[Extensible] enum E { One, [Default] Two, };')
+    ])