internal/lsp: avoid panic caused by assuming file ends with newline
importPrefix in format.go computes the end of the package statement
including a trailing newline. This causes a panic if the user has
not typed the newline. The code now checks for that case.
Fixes golang/go#40208
Change-Id: I4c5118a5de78027e6c5e6ed91dfddca81e38f7e9
Reviewed-on: https://go-review.googlesource.com/c/tools/+/242638
Reviewed-by: Heschi Kreinick <heschi@google.com>
diff --git a/internal/lsp/source/format.go b/internal/lsp/source/format.go
index d7629ea..2f3dab7 100644
--- a/internal/lsp/source/format.go
+++ b/internal/lsp/source/format.go
@@ -214,6 +214,9 @@
}
if importEnd == 0 {
importEnd = pkgEnd
+ if importEnd > len(src) {
+ importEnd-- // pkgEnd is off by 1 because Pos is 1-based
+ }
}
for _, c := range f.Comments {
if int(c.End()) > importEnd {
diff --git a/internal/lsp/source/format_test.go b/internal/lsp/source/format_test.go
index 845c87c..f929812 100644
--- a/internal/lsp/source/format_test.go
+++ b/internal/lsp/source/format_test.go
@@ -10,6 +10,7 @@
func TestImportPrefix(t *testing.T) {
var tdata = []data{
+ {"package foo", "package foo"},
{"package foo\n", "package foo\n"},
{"package foo\n\nfunc f(){}\n", "package foo\n"},
{"package foo\n\nimport \"fmt\"\n", "package foo\n\nimport \"fmt\""},
@@ -24,7 +25,7 @@
for i, x := range tdata {
got := importPrefix([]byte(x.input))
if got != x.want {
- t.Errorf("%d: got\n%q, wanted\n%q", i, got, x.want)
+ t.Errorf("%d: got\n%q, wanted\n%q for %q", i, got, x.want, x.input)
}
}
}
