testing lambda functions: block beta testing 08/17

[hugobowne]

can we test the definition and use of lambda function?

E.g.

# Define echo_word as a lambda function: echo_word
echo_word = (lambda word1, echo: word1 * echo)

and

# Create a list of strings: spells
spells = ['protego', 'accio', 'expecto patronum', 'legilimens']

# Use map() to apply a lambda function over spells: shout_spells
shout_spells = map(lambda item: item + '!!!', spells)

[vvnkr]

Testing the definition is not possible ATM but I think you can test the functionality of a lambda function using test_expression_result().

E.g.

test_expression_result(expr_code="echo_word('ECHO!!', 5)")

This will compare the result of expr_code in the student and solution environment (and since these environments contain the defined lambda expression, it tests whether they return the same).

[filipsch]

@vincentvankrunkelsven thanks for sharing this.
@hugobowne The workaround that Vincent mentions indeed allows you to indirectly test a lambda functions, but it's not ideal.

I'll try to look into a decent way of providing support for lambda functions by start of week next week (August 8).

[filipsch]

@hugobowne a function test_lambda_function() that looks very much like test_function_definition() has been added; it'll be on staging soon.
Wiki article will be added here

[filipsch]

Will go live tomorrow