Fix issue #1964

[mgabeler-lee-6rs]

Purpose

Fix #1964 by adding a helper method to walk the stub parent links to find the wrappedMethod value for the callsThrough behavior.

Background

If you try to use the callsThrough behavior on a withArgs stub, calling the stub with the matching args will fail, because the behavior fails to locate the original wrapped method to call through to.

This is effectively a followup to #1442 / #1549.

Solution - optional

A simple helper method walks up stub.parent links until it finds a stub that has a wrappedMethod member.

How to verify - mandatory

1. Check out this branch
2. npm install
3. npm test, or just npm run test-node, or just npm run test-node --grep 1964 to run the issue-specific test case

Checklist for author

• npm run lint passes
• References to standard library functions are cached.
  • N/A -- no standard library functions used

[coveralls]

Pull Request Test Coverage Report for Build 2859

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.02%) to 94.186%

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Files with Coverage Reduction	New Missed Lines	%
sinon/behavior.js	5	95.92%

Totals
Change from base Build 2857:	-0.02%
Covered Lines:	1660
Relevant Lines:	1729

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💛 - Coveralls

[fatso83]

Very nice and readable test. Thank you! I just have one comment that I think should be addressed, with regards to the Fail Fast principle.

[fatso83]

Thanks!