feat: spies

[crookse]

Closes #151

TODO

• Write tests for VerificationError
• Write tests for spies on classes
• Write tests for spies on object methods
• Write tests for spies on function expressions
• Write tests for spies on fakes
• Write tests for spies in tests/cjs and tests/esm
• Write tests for FunctionExpressionVerifier
• Write tests for MethodVerifier
• Write documentation in drashland/webiste-v2 repo (feat(rhum/v2.x): spies website-v2#158)

Summary

• feat: Adds spies
  • Users can create a spy out of a class via const spyClass = Spy(SomeClass)
  • Users can spy on an object's method via const spyMethod = Spy(obj, "nameOfMethod", optionalReturnValue)
  • Users can spy on a function expression via const spyMethod = Spy(func, optionalReturnValue)
  • Limitations:
    • When using CommonJS, there is no way for Rhum to differentiate between classes and function expressions. This means spying on function expressions in a CommonJS codebase is not supported.
• feat: Add FunctionExpressionVerifier for Spy stub call verification
• refactor: Add CallableVerifier that MethodVerifier can extend
  • This was done to allow shared verification logic between the new FunctionExpressionVerifier for Spy stubs and the MethodVerifier used between the Mock and the Spy test doubles
• refactor: Alphabetize methods, properties, error classes, interfaces, and types
• refactor: Improved VerificationError class (formerly MethodVerificationError)
  • Changed the name because it's a generic verification error class, not just a method verification. It's also used for function expression verifications.
  • Adds more lines to the ignoredLines array so that we don't accidentally show a random file.
  • Fixes issue with the stack trace sometimes showing the problematic file twice. If it's shown twice, then we just slice off the duplicate.
• refactor: clean up a lot of the code
  • DRY code more
  • There are three verifiers (one for mocks, one for spy methods, and one for spy function expressions). These duplicated a lot of code. They now extend a parent class (CallableVerifier) to reduce the amount of duplicated code.
  • Remove dead code (e.g., MethodArguments type)
  • Change semantics of variables and method names to better reflect what they are doing and what they are used for. For example, MethodCalls is now MockMethodCalls because it only pertains to mocks.
• docs: Add all necessary doc blocks to internal code and interfaces
  • Improves type-hinting for the user (you can see how it's working by looking using the tests in visual studio code)
  • Improves documentation in general (for our development efforts)
  • Adds hella lines of code to this pull request
  • Consolidates doc block descriptions to reference interfaces. Not sure why I was like, "Let's document this here, then document it again here." So, I just referenced the interface like "See IMock.calls".
• build: Update build process for CJS and ESM
  • Adds spy-related files
  • Adds verifiers
  • Fixes issue with stacked import/export statements. For example, the following wasn't working and now it does:

    import {
     something,
     something,
    something
    } from "some/path/file.ts"
    
    export {
     something,
     something,
    something
    } from "some/path/file.ts"

[ebebbington]

one comment, but no biggie, overral LGTM :D Some really nice code here, of course didnt check jest generated, and im happy if you think you've hit enough during the tesst

[ebebbington]

missed todo? not sure if this is crucial or could be done later down the line

[crookse]

i didn't want to bloat the PR more with hella changes so i added these two issues:

#166
#167

[ebebbington]