imports: fix mangled comments after package clause insertion
Fixes golang/go#12097
Change-Id: Ie6a6aa997e89700e49d703b7fd00f515b03ad6f8
Reviewed-on: https://go-review.googlesource.com/93235
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/imports/fix_test.go b/imports/fix_test.go
index bc18772..83ceb02 100644
--- a/imports/fix_test.go
+++ b/imports/fix_test.go
@@ -866,6 +866,29 @@
}
`,
},
+
+ {
+ name: "issue #12097",
+ in: `// a
+// b
+// c
+
+func main() {
+ _ = fmt.Println
+}`,
+ out: `package main
+
+import "fmt"
+
+// a
+// b
+// c
+
+func main() {
+ _ = fmt.Println
+}
+`,
+ },
}
func TestFixImports(t *testing.T) {
diff --git a/imports/imports.go b/imports/imports.go
index bd67f91..0623248 100644
--- a/imports/imports.go
+++ b/imports/imports.go
@@ -63,7 +63,6 @@
sortImports(fileSet, file)
imps := astutil.Imports(fileSet, file)
-
var spacesBefore []string // import paths we need spaces before
for _, impSection := range imps {
// Within each block of contiguous imports, see if any
@@ -136,11 +135,18 @@
// If this is a declaration list, make it a source file
// by inserting a package clause.
- // Insert using a ;, not a newline, so that the line numbers
- // in psrc match the ones in src.
- psrc := append([]byte("package main;"), src...)
+ // Insert using a ;, not a newline, so that parse errors are on
+ // the correct line.
+ const prefix = "package main;"
+ psrc := append([]byte(prefix), src...)
file, err = parser.ParseFile(fset, filename, psrc, parserMode)
if err == nil {
+ // Gofmt will turn the ; into a \n.
+ // Do that ourselves now and update the file contents,
+ // so that positions and line numbers are correct going forward.
+ psrc[len(prefix)-1] = '\n'
+ fset.File(file.Package).SetLinesForContent(psrc)
+
// If a main function exists, we will assume this is a main
// package and leave the file.
if containsMainFunc(file) {
@@ -149,8 +155,7 @@
adjust := func(orig, src []byte) []byte {
// Remove the package clause.
- // Gofmt has turned the ; into a \n.
- src = src[len("package main\n"):]
+ src = src[len(prefix):]
return matchSpace(orig, src)
}
return file, adjust, nil
