1 files changed, 97 insertions, 0 deletions
diff --git a/src/go/ast/print_test.go b/src/go/ast/print_test.go
new file mode 100644
index 000000000..210f16430
--- /dev/null
+++ b/src/go/ast/print_test.go
@@ -0,0 +1,97 @@
+// Copyright 2011 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 ast
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+var tests = []struct {
+	x interface{} // x is printed as s
+	s string
+}{
+	// basic types
+	{nil, "0  nil"},
+	{true, "0  true"},
+	{42, "0  42"},
+	{3.14, "0  3.14"},
+	{1 + 2.718i, "0  (1+2.718i)"},
+	{"foobar", "0  \"foobar\""},
+
+	// maps
+	{map[Expr]string{}, `0  map[ast.Expr]string (len = 0) {}`},
+	{map[string]int{"a": 1},
+		`0  map[string]int (len = 1) {
+		1  .  "a": 1
+		2  }`},
+
+	// pointers
+	{new(int), "0  *0"},
+
+	// arrays
+	{[0]int{}, `0  [0]int {}`},
+	{[3]int{1, 2, 3},
+		`0  [3]int {
+		1  .  0: 1
+		2  .  1: 2
+		3  .  2: 3
+		4  }`},
+	{[...]int{42},
+		`0  [1]int {
+		1  .  0: 42
+		2  }`},
+
+	// slices
+	{[]int{}, `0  []int (len = 0) {}`},
+	{[]int{1, 2, 3},
+		`0  []int (len = 3) {
+		1  .  0: 1
+		2  .  1: 2
+		3  .  2: 3
+		4  }`},
+
+	// structs
+	{struct{}{}, `0  struct {} {}`},
+	{struct{ x int }{007}, `0  struct { x int } {}`},
+	{struct{ X, y int }{42, 991},
+		`0  struct { X int; y int } {
+		1  .  X: 42
+		2  }`},
+	{struct{ X, Y int }{42, 991},
+		`0  struct { X int; Y int } {
+		1  .  X: 42
+		2  .  Y: 991
+		3  }`},
+}
+
+// Split s into lines, trim whitespace from all lines, and return
+// the concatenated non-empty lines.
+func trim(s string) string {
+	lines := strings.Split(s, "\n")
+	i := 0
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if line != "" {
+			lines[i] = line
+			i++
+		}
+	}
+	return strings.Join(lines[0:i], "\n")
+}
+
+func TestPrint(t *testing.T) {
+	var buf bytes.Buffer
+	for _, test := range tests {
+		buf.Reset()
+		if err := Fprint(&buf, nil, test.x, nil); err != nil {
+			t.Errorf("Fprint failed: %s", err)
+		}
+		if s, ts := trim(buf.String()), trim(test.s); s != ts {
+			t.Errorf("got:\n%s\nexpected:\n%s\n", s, ts)
+		}
+	}
+}