change PrefixEachLine to add newline at the end

internal/testutil/reindent.go

@@ -43,12 +43,9 @@ func Reindent(in string) []byte {
 func PrefixEachLine(text string, prefix string) string {
 	var result strings.Builder
 	lines := strings.Split(text, "\n")
-	for i, line := range lines {
-		newLine := prefix + line
-		if i < len(lines)-1 {
-			newLine += "\n"
-		}
-		_, err := result.WriteString(newLine)
+	for _, line := range lines {
+		prefixed := prefix + line + "\n"
+		_, err := result.WriteString(prefixed)
 		if err != nil {
 			panic(err)
 		}

internal/testutil/reindent_test.go

@@ -3,8 +3,9 @@ package testutil_test
 import (
 	"strings"
 
-	"github.com/canonical/chisel/internal/testutil"
 	. "gopkg.in/check.v1"
+
+	"github.com/canonical/chisel/internal/testutil"
 )
 
 type reindentTest struct {
@@ -78,26 +79,26 @@ type prefixEachLineTest struct {
 var prefixEachLineTests = []prefixEachLineTest{{
 	raw:    "a\n\tb\n  \t\tc\td\n\t ",
 	prefix: "foo",
-	result: "fooa\nfoo\tb\nfoo  \t\tc\td\nfoo\t ",
+	result: "fooa\nfoo\tb\nfoo  \t\tc\td\nfoo\t \n",
 }, {
 	raw:    "foo",
 	prefix: "pref",
-	result: "preffoo",
+	result: "preffoo\n",
 }, {
 	raw:    "",
 	prefix: "",
-	result: "",
+	result: "\n",
 }, {
 	raw:    "\n",
 	prefix: "\t",
-	result: "\t\n\t",
+	result: "\t\n\t\n",
 }}
 
 func (s *S) TestPrefixEachLine(c *C) {
 	for _, test := range prefixEachLineTests {
 		c.Logf("Test: %#v", test)
 
-		indented := testutil.PrefixEachLine(test.raw, test.prefix)
-		c.Assert(string(indented), Equals, test.result)
+		prefixed := testutil.PrefixEachLine(test.raw, test.prefix)
+		c.Assert(prefixed, Equals, test.result)
 	}
 }