annotate.js - Asserts your function invariants
annotate.js
allows you to attach certain metadata to your functions. For
instance you could document invariants of your function this way. In
addition you can attach an optional description you can access later on.
This metadata can be used by tools such as suite.js in order to generate tests. In addition you can access the metadata via REPL.
The usage is quite simple as the following example illustrates:
// let's define some function to annotate { return a + b;} // type checkers from is-js (https://npmjs.org/package/is-js)var addNumbers = ;var addStrings = ; // you can assert invariants toovar addPositive = ; // postcondition // it is possible to chain guardsvar fib = ; // invariants may depend on each othervar clamp = ; // furthermore it is possible to pass a variable amount of argsvar min = ; { return a >= 0;}
The annotate
function will create a new function that contains the metadata as
properties _name
, _doc
and _invariants
. In case an invariant does not
pass during execution, it won't execute and gives a warning instead.
Related Projects
- suite.js - Constructs tests based on invariant data (fuzzing)
- funkit - Collection of utilities tested using
annotate.js
andsuite.js
Acknowledgements
- Kris Jordan's multimethod.js - Provided inspiration for the API
License
annotate.js
is available under MIT. See LICENSE for more details.