Dart: do not derive from classes annotated as 'visibleForTesting' #1642
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This change introduces a new LIME file to smoke tests, which causes generation of the code for base and derived classes, which have static methods. The classes are generated only for Dart and the intention is to show how 'visibleForTesting' annotation is used. Sadly, the base type annotated as visible for testing is used as a base class of the derived impl type. It causes linter warnings. Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
This change introduces a new LIME file to functional tests, which causes generation of the code for base and derived classes, which have static methods. This will be used as a reference to confirm that the code builds and runs after the fix is implemented. Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
In order to allow users to mock static functions in classes the 'prototype' approach was implemented in the past. It uses prototype class to redirect static function calls. A class with '$Impl' suffix is created as a prototype. It is annotated as 'visibleForTesting' and exported from the library. The user may provide its own implementation in tests and this way redirect the calls to the mock (after setting it as prototype). Sadly, when a class is derived from the class, which has static methods, then its '$Impl' derives from the '$Impl' of base class. This leads to linter warnings: 'invalid_use_of_visible_for_testing_member'. This change introduces a new type called '$HiddenImpl', which is defined only when the class is open and has static functions. The '$HiddenImpl' is not exported and therefore, the user cannot use it directly. Still, the user may use the old approach to redirect the calls to mock. The '$HiddenImpl' is derived from an ordinary '$Impl' and its usage does not generate linter warnings when the '$Impl' of derived class uses it. The '$HiddenImpl' is used only to provide implementation of methods from the base class. Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
This commit adjusts the expected output of smoke tests for generated classes, which reflects the change in mustache templates. '$HiddenImpl' classes are generated when needed. In places where the class was derived from 'visibleForTesting' type now '$HiddenImpl' is used. Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
This commit implements a new test case, which verifies that mocking of static methods still can be achieved in the same way that it was in the past to ensure, that the users, who use mocks do not experience any problems. Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
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A note for reviewers:
The initial design of mock-ability of static functions in Dart can be found here: |
Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
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After the offline discussion with @Hsilgos I am closing this PR. The fix looks like a hack. It will be replaced via |
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Just for a reference -- the PR was closed, because the problem is fixed via: #1644 |
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----- Motivation -----
In order to allow users to mock static functions in classes
the 'prototype' approach was implemented in the past. It uses
prototype class to redirect static function calls.
A class with '$Impl' suffix is created as a prototype. It is
annotated as 'visibleForTesting' and exported from the library.
The user may provide its own implementation in tests and this
way redirect the calls to the mock (after setting it as prototype).
Sadly, when a class is derived from the class, which has static
methods, then its '$Impl' derives from the '$Impl' of base class.
This leads to linter warnings: 'invalid_use_of_visible_for_testing_member'.
----- Implemented solution -----
This change introduces a new type called '$HiddenImpl', which is
defined only when the class is open and has static functions.
The '$HiddenImpl' is not exported and therefore, the user cannot use it
directly. Still, the user may use the old approach to redirect the calls
to mock.
The '$HiddenImpl' is derived from an ordinary '$Impl' and its usage does
not generate linter warnings when the '$Impl' of derived class uses it,
because '$HiddenImpl' is not annotated as 'visibleForTesting'.
The '$HiddenImpl' is used only to provide implementation of methods from
the base class.