internal/lsp: test adding imports for package statements with comments

Test that having a comment at the start of a file allows imports
to be added correctly.

Updates golang/go#33721

Change-Id: Id1673c2509537413710b73261ad2a59afe06b93f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/190800
Run-TryBot: Suzy Mueller <suzmue@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/internal/lsp/source/imports_test.go b/internal/lsp/source/imports_test.go
index 0a62f6f..2d054db 100644
--- a/internal/lsp/source/imports_test.go
+++ b/internal/lsp/source/imports_test.go
@@ -84,10 +84,36 @@
 		},
 	},
 	{
-		name: "package statement comments",
+		// Issue 33721: add import statement after package declaration preceded by comments.
+		name: "issue 33721 package statement comments before",
 		pkg:  "os",
-		in: `// This is a comment
-package main // This too`,
+		in: `// Here is a comment before
+package main
+`,
+		want: []importInfo{
+			importInfo{
+				name: "",
+				path: "os",
+			},
+		},
+	},
+	{
+		name: "package statement comments same line",
+		pkg:  "os",
+		in: `package main // Here is a comment after
+`,
+		want: []importInfo{
+			importInfo{
+				name: "",
+				path: "os",
+			},
+		},
+	},
+	{
+		name: "package statement comments before and after",
+		pkg:  "os",
+		in: `// Here is a comment before
+package main // Here is a comment after`,
 		want: []importInfo{
 			importInfo{
 				name: "",