Changing imports removes comment at the top of a file

[breml]

Given a Go source file with a comment at the top of the file (not a package comment):

// Copyright 2022 ...

package main

import (
	"cmd/internal/edit"
)

func main() {
	_ = edit.Buffer
}

and a patch to modify the imports:

@@
var randomIdentifier identifier
@@
-import "cmd/internal/edit"
+import "github.com/foo/bar/internal/edit"

edit.randomIdentifier

the comment at the top is removed by gopatch, resulting with the following file:

package main

import "github.com/foo/bar/internal/edit"

func main() {
	_ = edit.Buffer
}

[breml]

The respective testdata file:

-- in.patch --
@@
var randomIdentifier identifier
@@
-import "cmd/internal/edit"
+import "github.com/foo/bar/internal/edit"

edit.randomIdentifier

-- comment.in.go --
// Copyright 2022 ...

package main

import (
	"cmd/internal/edit"
)

func main() {
	_ = edit.Buffer
}

-- comment.out.go --
// Copyright 2022 ...

package main

import "github.com/foo/bar/internal/edit"

func main() {
	_ = edit.Buffer
}

This returns:

$ go test .
--- FAIL: TestIntegration (0.04s)
    --- FAIL: TestIntegration/replace_import_with_top_level_comment (0.00s)
        --- FAIL: TestIntegration/replace_import_with_top_level_comment/comment (0.00s)
            e2e_test.go:127: 
                        Error Trace:    e2e_test.go:127
                        Error:          Not equal: 
                                        expected: "// Copyright 2022 ...\n\npackage main\n\nimport \"github.com/foo/bar/internal/edit\"\n\nfunc main() {\n\t_ = edit.Buffer\n}\n"
                                        actual  : "package main\n\nimport \"github.com/foo/bar/internal/edit\"\n\nfunc main() {\n\t_ = edit.Buffer\n}\n"
                                    
                                        Diff:
                                        --- Expected
                                        +++ Actual
                                        @@ -1,3 +1 @@
                                        -// Copyright 2022 ...
                                        -
                                         package main
                        Test:           TestIntegration/replace_import_with_top_level_comment/comment
FAIL
FAIL    github.com/uber-go/gopatch      0.047s
FAIL