1 files changed, 75 insertions, 0 deletions
diff --git a/gopls/internal/lsp/source/format_test.go b/gopls/internal/lsp/source/format_test.go
new file mode 100644
index 000000000..fac80c311
--- /dev/null
+++ b/gopls/internal/lsp/source/format_test.go
@@ -0,0 +1,75 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package source
+
+import (
+	"strings"
+	"testing"
+
+	"golang.org/x/tools/gopls/internal/lsp/tests/compare"
+)
+
+func TestImportPrefix(t *testing.T) {
+	for i, tt := range []struct {
+		input, want string
+	}{
+		{"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\""},
+		{"package foo\nimport (\n\"fmt\"\n)\n", "package foo\nimport (\n\"fmt\"\n)"},
+		{"\n\n\npackage foo\n", "\n\n\npackage foo\n"},
+		{"// hi \n\npackage foo //xx\nfunc _(){}\n", "// hi \n\npackage foo //xx\n"},
+		{"package foo //hi\n", "package foo //hi\n"},
+		{"//hi\npackage foo\n//a\n\n//b\n", "//hi\npackage foo\n//a\n\n//b\n"},
+		{
+			"package a\n\nimport (\n  \"fmt\"\n)\n//hi\n",
+			"package a\n\nimport (\n  \"fmt\"\n)\n//hi\n",
+		},
+		{`package a /*hi*/`, `package a /*hi*/`},
+		{"package main\r\n\r\nimport \"go/types\"\r\n\r\n/*\r\n\r\n */\r\n", "package main\r\n\r\nimport \"go/types\"\r\n\r\n/*\r\n\r\n */\r\n"},
+		{"package x; import \"os\"; func f() {}\n\n", "package x; import \"os\""},
+		{"package x; func f() {fmt.Println()}\n\n", "package x"},
+	} {
+		got, err := importPrefix([]byte(tt.input))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if d := compare.Text(tt.want, got); d != "" {
+			t.Errorf("%d: failed for %q:\n%s", i, tt.input, d)
+		}
+	}
+}
+
+func TestCRLFFile(t *testing.T) {
+	for i, tt := range []struct {
+		input, want string
+	}{
+		{
+			input: `package main
+
+/*
+Hi description
+*/
+func Hi() {
+}
+`,
+			want: `package main
+
+/*
+Hi description
+*/`,
+		},
+	} {
+		got, err := importPrefix([]byte(strings.ReplaceAll(tt.input, "\n", "\r\n")))
+		if err != nil {
+			t.Fatal(err)
+		}
+		want := strings.ReplaceAll(tt.want, "\n", "\r\n")
+		if d := compare.Text(want, got); d != "" {
+			t.Errorf("%d: failed for %q:\n%s", i, tt.input, d)
+		}
+	}
+}