mojo/public/tools/mojom/version_compatibility_unittest.py
def testNewValueInExistingVersion(self):
    """Adding a value to an existing version is not allowed, even if the old
    enum was marked [Extensible]. Note that it is irrelevant whether or not the
    new enum is marked [Extensible]."""
    self.assertNotBackwardCompatible('[Extensible] enum E { kFoo, kBar };',
                                     'enum E { kFoo, kBar, kBaz };')
    self.assertNotBackwardCompatible(
        '[Extensible] enum E { kFoo, kBar };',
        '[Extensible] enum E { kFoo, kBar, kBaz };')
    self.assertNotBackwardCompatible(
        '[Extensible] enum E { kFoo, [MinVersion=1] kBar };',
        'enum E { kFoo, [MinVersion=1] kBar, [MinVersion=1] kBaz };')
Adding a value to an existing version is not allowed, even if the old
    enum was marked [Extensible]. Note that it is irrelevant whether or not the
    new enum is marked [Extensible].
Adding a value to an existing version is not allowed, even if the old
enum was marked [Extensible]. Note that it is irrelevant whether or not the
new enum is marked [Extensible].
Adding a value to an existing version is not allowed even if the old enum was marked [ Extensible ] . Note that it is irrelevant whether or not the new enum is marked [ Extensible ] .
def testNewValueInExistingVersion(self):
    self.assertNotBackwardCompatible('[Extensible] enum E { kFoo, kBar };',
                                     'enum E { kFoo, kBar, kBaz };')
    self.assertNotBackwardCompatible(
        '[Extensible] enum E { kFoo, kBar };',
        '[Extensible] enum E { kFoo, kBar, kBaz };')
    self.assertNotBackwardCompatible(
        '[Extensible] enum E { kFoo, [MinVersion=1] kBar };',
        'enum E { kFoo, [MinVersion=1] kBar, [MinVersion=1] kBaz };')
def testNewValueInExistingVersion ( self ) : self . assertNotBackwardCompatible ( '[Extensible] enum E { kFoo, kBar };' , 'enum E { kFoo, kBar, kBaz };' ) self . assertNotBackwardCompatible ( '[Extensible] enum E { kFoo, kBar };' , '[Extensible] enum E { kFoo, kBar, kBaz };' ) self . assertNotBackwardCompatible ( '[Extensible] enum E { kFoo, [MinVersion=1] kBar };' , 'enum E { kFoo, [MinVersion=1] kBar, [MinVersion=1] kBaz };' )
Adding a value to an existing version is not allowed, even if the old
enum was marked [Extensible].
Adding a value to an existing version is not allowed even if the old enum was marked [ Extensible ] .
"""Adding a value to an existing version is not allowed, even if the old
    enum was marked [Extensible]. Note that it is irrelevant whether or not the
    new enum is marked [Extensible]."""
self