The issue occurs only when deleting an import that has a blank line immediately preceding,
and other imports before that.
Currently, DeleteImport assumes there's a blank line-sized hole left behind
where the import was, and always deletes it. That blank line-sized hole is there in all cases
except the above edge case.
This fix checks for that edge case, and does not remove the blank line-sized hole.
The CL also adds a previously failing test case that catches this scenario. After the change to
DeleteImport, the new test passes (along with all other tests).
Fixesgolang/go#7679.
Note that there is no attempt to ensure the result *ast.File and *token.FileSet are perfectly
matching to what you would get if you printed the AST and parsed it back. This is how the
rest of the package and the current tests work (i.e., they only check that printing the AST gives
the correct output).
Changing that is very hard, if not impossible, at least not
without resorting to manipulating AST via printing, text manipulation and parsing.
This is okay for most usages, but it does create potential problems. For example,
astutil.Imports() currently only works correctly on freshly parsed AST. If that AST
is manipulated via astutil funcs, then Imports() may not always generate correct
output. However, thas is a separate issue and should be treated as such.
LGTM=bradfitz
R=golang-codereviews, gobot, adonovan, bradfitz
CC=golang-codereviews
https://golang.org/cl/92250045
This fixes a case where adding an import when there are is no
existing import declaration can corrupt the position of
comments attached to types. This was the last known
goimports/astutil corruption case.
See golang.org/issue/6884 for more details.
Unfortunately this requires changing the API to add a
*token.FileSet, which we should've had before. I will update
goimports (the only user of this API?) immediately after
submitting this.
This CL also contains a hack (used only in this case of no
imports): rather than fix the comment positions by hand
(something that only Robert might know how to do), it instead
just prints the AST, manipulates the source, and re-parses
the AST. We can fix up later.
Fixesgolang/go#6884
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/38270043
Lifts the import management utilities from gofix into
a package, so they can be used by goimports.
R=bradfitz
CC=golang-dev
https://golang.org/cl/22430043
