Fixture injection

[la10736]

Define a fixture procedural macro that define a fixture.

Input fixture can be simple functions or should be fixture functions. Fixture function will return Fixture wrapper that can be nested and control value life cycle.

We'll associate to fixture two static methods:

• get(args) that return exactly what the original function returns
• default() that return get()'s result by resolve all arguments as fixtures

Fixture will execute tear down at the end of the test and not when fixture value will be dropped.

We leave teardown implementation for next release and a new ticket. Maybe get and default will return a tuple instead a wrapper and Fixture will be a trait implemented on that tuples.

Note: We not use a wrapper for fixture return type to not go deep in the impl resolution hell. By now struct cannot wrap any function return type.

[la10736]

TODO

• Test new() with some argumets
• Fixture should maintains the original visibility
• Fixture that take and return impl types
• Fixture that take and return dyn types
• Fixture that take and return generic object

[la10736]

Fixture should not create a struct that wrap function return value to not fight with impl, dyn and generics. Should just give some static method to get

• the fixture by given all inputs (just a tuple and a TearDownGuard?)
• the default fixture that resolve all arguments by call sub fixture

[la10736]

Done