catch2/docs/logging.md
2013-06-14 08:32:48 +01:00

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Logging macros

Additional messages can be logged during a test case.

Streaming macros

All these macros allow heterogenous sequences of values to be streaming using the insertion operator (<<) in the same way that std::ostream, std::cout, etc support it.

E.g.:

INFO( "The number is " << i );

(Note that there is no initial << - instead the insertion sequence is placed in parentheses.) These macros come in three forms:

INFO( message expression )

The message is logged to a buffer, but only reported if a subsequent failure occurs within the same test case. This allows you to log contextual information in case of failures which is not shown during a successful test run. The buffer is cleared on the next successful assertion.

SCOPED_INFO( message expression )

As INFO, but is only in effect during the current scope. If a failure occurs beyond the end of the scope the message is not logged. In a looped block the message is reset on each iteration.

WARN( message expression )

The message is always reported.

FAIL( message expression )

The message is reported and the test case fails.

Quickly capture a variable value

CAPTURE( expression )

Sometimes you just want to log the name and value of a variable. While you can easily do this with the INFO macro, above, as a convenience the CAPTURE macro handles the stringising of the variable name for you (actually it works with any expression, not just variables).

E.g.

CAPTURE( theAnswer );

This would log something like:

"theAnswer := 42"

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