Ensure test after() callback is always executed

[Benjamin-Dobell]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?
N/A - The fix is for the test suite itself.

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

Description

Took me a little while to track down what was going on here. Basically, if the emit-uint8array-no-buffer test fails, then all subsequent tests will fail to execute. This is because the emit-uint8array-no-buffer test has a before function which deletes global.Buffer, and and an after function which is supposed to restore it.

However, prior to this PR, the after callback is not guaranteed to be called so global.Buffer remains undefined. The lack of global.Buffer causes issues with, magic-string, but likely elsewhere too.

rollup/test/form/samples/emit-uint8array-no-buffer/_config.js

Lines 6 to 11 in 889fa52

	before() {
	delete global.Buffer;
	},
	after() {
	global.Buffer = Buffer;
	},

[codecov]

Codecov Report

Merging #3936 (3cf9cbc) into master (889fa52) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3936   +/-   ##
=======================================
  Coverage   97.18%   97.18%           
=======================================
  Files         188      188           
  Lines        6681     6681           
  Branches     1944     1944           
=======================================
  Hits         6493     6493           
  Misses         99       99           
  Partials       89       89           

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[lukastaegert]

Good catch!