def test_breaker_will_raise(testbreakbox):
"""
Using the circuit_breaker context should raise CircuitBroken if
called on a CircuitBreaker that has already tripped.
"""
breaker = testbreakbox["basic"]
raisefault("basic", testbreakbox)
assert breaker.tripped is True
with pytest.raises(CircuitBroken):
with circuit_breaker("basic", breakerbox=testbreakbox):
1/0
def test_breaker_blocks(testbreakbox):
"""
A circuit_breaker context with the blocks=True flag should not raise, but
instead wait.
"""
breaker = testbreakbox["short"]
raisefault("short", testbreakbox)
assert breaker.tripped is True
with pytest.raises(gevent.Timeout), gevent.Timeout(0.001):
with circuit_breaker("short", block=True, breakerbox=testbreakbox):
raise Exception("Should not get here.")
def test_breaker_clears_on_success(testbreakbox):
"""
Once a circuit_breaker context has passed, it should completely clear the
breaker so that future uses will succeed as normal.
"""
breaker = testbreakbox["multi"]
raisefault("multi", testbreakbox)
assert breaker.fails == 1
with circuit_breaker("multi", breakerbox=testbreakbox):
pass # Should cause 'clear' to be run.
assert breaker.fails == 0
def raisefault(brk_name, breakerbox):
"""
Deliberately raise a fault in the named breaker.
Helper function to avoid needing to type out a full try/except block
in every test.
"""
try:
with circuit_breaker(brk_name, breakerbox=breakerbox):
1/0
except Exception:
pass # Swallow, we know.
def test_breaker_reset_fails_not_fully_reset(testbreakbox):
"""
A circuit_breaker's reset timer task should set its failure state to
one below the threshold, rather than completely clear it.
"""
breaker = testbreakbox["shortmulti"]
for x in range(3):
raisefault("shortmulti", testbreakbox)
assert breaker.tripped is True
gevent.sleep(0.02)
# Reset should run and set us to threshold-1 for a try.
assert breaker.tripped is False
assert breaker.fails == 2
# One more should be back at threshold.
raisefault("shortmulti", testbreakbox)
assert breaker.tripped is True
# And clear it fully.
with circuit_breaker("shortmulti", breakerbox=testbreakbox, block=True):
pass
assert breaker.tripped is False
assert breaker.fails == 0
def slow_worker():
with circuit_breaker("basic", breakerbox=testbreakbox):
gevent.sleep(0.01)
def waiting_task():
with circuit_breaker("short", block=True):
gevent.sleep(0.001)
result["done"] = True