support patches with comments

[ccoVeille]

I'm trying to use patch to perform something like this

@@
var f identifier
@@
-func f(t *testing.T) {
+func f(t *testing.T) {
+   t.Helper() // my comment
+
+   t.Helper()
    ...
}

This code is part of a bigger patch and code reorganization. So this is a code to replicate the issue/question I want to talk about.

My issues right now are that:

• the code adds the t.Helper() but not the comment
• the new line is not added

I would like to know if I'm not missing something obvious

[ccoVeille]

Please note that

@@
var f identifier
@@
-func f(t *testing.T) {
+func f(t *testing.T) {
+   t.Helper()
+
+   t.Helper()
    ...
}

will rewrite this

func myTestHelper(t *testing) {
   require.Fail(t)
}

to

func myTestHelper(t *testing) {
   t.Helper()
   t.Helper()
   require.Fail(t)
}

So no line feed

Once again, please note it's pseudo code

[abhinav]

Hey @ccoVeille. gopatch is limited in that aspect: it only transforms significant AST nodes.
It could probably do something smarter about them, but the original design left out comments and newlines with more focus on just transforming code.

[ccoVeille]

I was thinking about using the tool to add //nolint somelinter // reason on some pattern I have in my code base.

I would love if comment could be supported.

I would prefer if it was possible, but I can leave without new lines.

Comment is a bit more painful