Coverage
Description:
Measures the t-wise coverage of a configuration suite: the fraction of all satisfiable combinations of t feature selections that are covered by at least one of the given configurations (1.0 = full coverage).
Application: Assesses how well a test suite of configurations exercises the feature interactions of a product line (e.g. before running expensive tests on each product).
Example: A suite of 10 random configurations may reach 0.89 pairwise coverage, i.e. it covers 89% of the valid pairs of feature selections.
Code Examples
Python easy to use facade usage
from flamapy.interfaces.python.flamapy_feature_model import FLAMAFeatureModel
# Load the feature model
fm = FLAMAFeatureModel("path/to/feature/model")
# Measure the pairwise (t=2) coverage of a configuration suite
sample = fm.sampling(size=10)
result = fm.coverage(sample, t=2)
print(result)
Python flamapy framework ADVANCED usage
from flamapy.core.discover import DiscoverMetamodels
# Initialize the discover metamodel
dm = DiscoverMetamodels()
# Get the fm metamodel representation using the transformation
# required to get to the fm metamodel
feature_model = dm.use_transformation_t2m("path/to/feature/model", 'fm')
# Manually call a M2M transformation to PySAT
sat_model = dm.use_transformation_m2m(feature_model, "pysat")
# Build the configuration suite to analyse, e.g. with a random sample
sampling = dm.get_operation(sat_model, 'PySATSampling')
sampling.set_sample_size(10)
sample = sampling.execute(sat_model).get_result()
# Get the operation
operation = dm.get_operation(sat_model, 'PySATCoverage')
# Set the configurations to measure and the interaction strength
operation.set_configurations(sample)
operation.set_t(2)
# Execute the operation
operation.execute(sat_model)
# Get and print the result
result = operation.get_result()
print(result)
Facade signature: coverage(self, configurations: Any, t: int = 2)
Inputs:
| name | type | required | default |
|---|---|---|---|
configurations |
Any | yes | — |
t |
int | no | 2 |
Default backend: sat
Implemented by:
| plugin | exact | scale limit |
|---|---|---|
| pysat_metamodel | yes | — |