3 Commits (stacks-variable-validations)

Author	SHA1	Message	Date
Radek Simko	0fe906fa8c	make copyrightfix	3 months ago
Martin Atkins	8a99c3c0e5	stacks+rpcapi: Add some missing copyright comments	3 years ago
Martin Atkins	13edd30479	stackeval: Test-only globals ... Because many stacks language features are dependent on others to do useful work, it's tempting to focus only on integration testing of combinations of features used together. However, we known from our experience with the modules runtime (the "terraform" package) that over time this becomes a huge maintenance burden, because any non-trivial change tends to invalidate hundreds or thousands of integration tests, and because of their broad scope its often hard in retrospect to figure out what exactly a particular test was aiming to test vs. what it was just relying on as a side-effect. To try to minimize these cross-dependencies and thus enable something closer to unit testing, here we introduce a special kind of symbol to the stacks language which is available only to unit tests in this package. "Test-only globals" -- an intentionally-clunky name to avoid squatting on useful names -- can be set as part of the Main object and, when defined, are available for use in all situations where we perform expression evaluation against a stack. The "globals" in the name represents that, unlike just about everything else, they are defined once but available in all stacks in the configuration tree. This design is a tradeoff: it introduces a bunch of extra code that is here entirely to support testing, but hopefully this code is segregated enough from everything else that it's unlikely to change significantly under future maintenance, thereby hopefully minimizing the need for future cross-cutting test maintenance too.	3 years ago