When recording the parent of an event or span, the MockCollector
treats an explicit parent of None (i.e. an event or span that is an
explicit root) in the same way as if there is no explicit root. This
leads to it picking up the contextual parent or treating the event or
span as a contextual root.
Solution
This change refactors the recording of the parent to use is_contextual
to distinguish whether or not an explicit parent has been specified. The
actual parent is also written into an Ancestry enum so that the
expected and actual values can be compared in a more explicit way.
Additionally, the Ancestry struct has been moved into its own module and
the check behavior has been fixed. The error message has also been
unified across all cases.
Another problem with the previous API is that the two methods
with_contextual_parent and with_explicit_parent are actually
mutually exclusive, a span or event cannot be both of them. It is also a
(small) mental leap for the user to go from with_*_parent(None) to
understanding that this means that a span or event is a root (either
contextual or explicit).
As such, the API has been reworked into a single method with_ancestry,
which takes an enum with the following four variants:
HasExplicitParent(String) (parent span name)
IsExplicitRoot
HasContextualParent(String) (parent span name)
IsContextualRoot
To make the interface as useable as possible, helper functions have been
defined in the expect module which can be used to create the enum
variants. Specifically, these take Into<String> parameter for the span
name.
Given the number of different cases involved in checking ancestry,
separate integration tests have been added to tracing-mock
specifically for testing all the positive and negative cases when
asserting on the ancestry of events and spans.
There were two tests in tracing-attributes which specified both an
explicit and a contextual parent. This behavior was never intended to
work as all events and spans are either contextual or not. The tests
have been corrected to only expect one of the two.
Fixes: #2440
PR details
This PR attempts to address the comments made on #2812.
To address this comment https://github.com/tokio-rs/tracing/pull/2812#discussion_r1399607052
the logic to pick the ancestry of an actual span or event has been centralised. This
required factoring out the logic to get the current span and to look up a span by ID,
since these are different between the Running (MockCollector) and the MockSubscriber
structs.
Motivation
When recording the parent of an event or span, the
MockCollectortreats an explicit parent ofNone(i.e. an event or span that is an explicit root) in the same way as if there is no explicit root. This leads to it picking up the contextual parent or treating the event or span as a contextual root.Solution
This change refactors the recording of the parent to use
is_contextualto distinguish whether or not an explicit parent has been specified. The actual parent is also written into anAncestryenum so that the expected and actual values can be compared in a more explicit way.Additionally, the
Ancestrystruct has been moved into its own module and the check behavior has been fixed. The error message has also been unified across all cases.Another problem with the previous API is that the two methods
with_contextual_parentandwith_explicit_parentare actually mutually exclusive, a span or event cannot be both of them. It is also a (small) mental leap for the user to go fromwith_*_parent(None)to understanding that this means that a span or event is a root (either contextual or explicit).As such, the API has been reworked into a single method
with_ancestry, which takes an enum with the following four variants:HasExplicitParent(String)(parent span name)IsExplicitRootHasContextualParent(String)(parent span name)IsContextualRootTo make the interface as useable as possible, helper functions have been defined in the
expectmodule which can be used to create the enum variants. Specifically, these takeInto<String>parameter for the span name.Given the number of different cases involved in checking ancestry, separate integration tests have been added to
tracing-mockspecifically for testing all the positive and negative cases when asserting on the ancestry of events and spans.There were two tests in
tracing-attributeswhich specified both an explicit and a contextual parent. This behavior was never intended to work as all events and spans are either contextual or not. The tests have been corrected to only expect one of the two.Fixes: #2440
PR details
This PR attempts to address the comments made on #2812.
Specifically to address this comment https://github.com/tokio-rs/tracing/pull/2812#discussion_r1399605164 by replacing
.with_explicit_parent()and.with_contextual_parent()methods with a single.with_ancestry()method.To address this comment https://github.com/tokio-rs/tracing/pull/2812#discussion_r1399607052 the logic to pick the ancestry of an actual span or event has been centralised. This required factoring out the logic to get the current span and to look up a span by ID, since these are different between the
Running(MockCollector) and theMockSubscriberstructs.