fix(#1363): package-comments ignores //nolint directives

[chavacava]

Closes #1363

Root cause of the bug: when checking package comments, the rule doesn't skip directive-comments at the right place.

[ccoVeille]

That's a lot of changes 😱

[chavacava]

That's a lot of changes 😱

Yes... I think I hit a bug in dots.Resolve when it runs on Windows. I don´t have a windows machine so... I tried to catch the bug by relying on the GH CI...

[ccoVeille]

I would say OK, but I cannot swear I reviewed everything

[chavacava]

I would say OK, but I cannot swear I reviewed everything

Thanks! The PR seems "complicated" but it does very few things:

1. Fix package-comments ignores //nolint directives #1363 by checking if the block comment attached to package declaration is not "empty" (after removing empty lines and directives)
2. Add a test case: the very same of package-comments ignores //nolint directives #1363
3. Add a new helper method in test utils to test a rule against a list of files (vs the usual against a single file): this is where it seems to be a lot of changes but it's just the original helper functions with some extra for-range to iterate over the list of files. (easier to read with a side-by-side diff or by directly reading the final file)

[ccoVeille]

Thanks for the details, I assumed it was something like that, yes

If you plan to squash your commits into one, what you wrote could be used as a good commit message

[alexandear]

Can be one-liner:

Suggested change

	return commentGroup.Text() == ""
	return commentGroup == nil || commentGroup.Text() == ""

[alexandear]

1. Tests for package-comments is inside the testdata/golint directory.
2. I assume we can add simply testdata/golint/package_doc7.go instead of modifying test suite:

//nolint:dupl
package foo

Before the fix:

$ go test ./...
?       github.com/mgechev/revive       [no test files]
ok      github.com/mgechev/revive/cli   0.504s
ok      github.com/mgechev/revive/config        1.181s
ok      github.com/mgechev/revive/formatter     0.855s
?       github.com/mgechev/revive/internal/astutils     [no test files]
?       github.com/mgechev/revive/internal/ifelse       [no test files]
?       github.com/mgechev/revive/internal/typeparams   [no test files]
ok      github.com/mgechev/revive/lint  0.674s
ok      github.com/mgechev/revive/logging       0.315s
ok      github.com/mgechev/revive/revivelib     1.050s
ok      github.com/mgechev/revive/rule  1.498s
--- FAIL: TestAll (0.90s)
    --- FAIL: TestAll/package_doc7.go (0.00s)
        golint_test.go:71: Unexpected problem at package_doc7.go:1: package comment should be of the form "Package foo ..."
FAIL
FAIL    github.com/mgechev/revive/test  2.314s
FAIL

After applying the fix:

$ go test ./...
?       github.com/mgechev/revive       [no test files]
ok      github.com/mgechev/revive/cli   (cached)
ok      github.com/mgechev/revive/config        (cached)
ok      github.com/mgechev/revive/formatter     (cached)
?       github.com/mgechev/revive/internal/astutils     [no test files]
?       github.com/mgechev/revive/internal/ifelse       [no test files]
?       github.com/mgechev/revive/internal/typeparams   [no test files]
ok      github.com/mgechev/revive/lint  (cached)
ok      github.com/mgechev/revive/logging       (cached)
ok      github.com/mgechev/revive/revivelib     0.326s
ok      github.com/mgechev/revive/rule  (cached)
ok      github.com/mgechev/revive/test  1.407s

See my example in #1371