code review 12420044: text/template/parse, html/template: copy Tree.Text duri...

src/pkg/text/template/parse/parse_test.go

 // 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 parse
 
 import (
         "flag"
         "fmt"
         "strings"
@@ skipping 314 matching lines @@
                 if err != nil {
                         t.Errorf("%q: unexpected error: %v", test.name, err)
                         continue
                 }
                 if empty := IsEmptyTree(tree.Root); empty != test.empty {
                         t.Errorf("%q: expected %t got %t", test.name, test.empty, empty)
                 }
         }
 }
 
+func TestErrorContextWithShallowTreeCopy(t *testing.T) {
+        tree, err := New("root").Parse("{{if true}}{{end}}", "", "", make(map[string]*Tree), nil)
+        if err != nil {
+                t.Fatalf("unexpected tree parse failure: %v", err)
+        }
+        // copy all available (exported) fields
+        treeCopy := &Tree{
+                Name:      tree.Name,
+                Root:      tree.Root.CopyList(),
+                ParseName: tree.ParseName,
+                Text:      tree.Text,
+        }
+        wantLocation, wantContext := tree.ErrorContext(tree.Root.Nodes[0])
+        gotLocation, gotContext := treeCopy.ErrorContext(treeCopy.Root.Nodes[0])
+        if wantLocation != gotLocation {
+                t.Errorf("wrong error location want %q got %q", wantLocation, gotLocation)
+        }
+        if wantContext != gotContext {
+                t.Errorf("wrong error location want %q got %q", wantContext, gotContext)
+        }
+}
+
 // All failures, and the result is a string that must appear in the error message.
 var errorTests = []parseTest{
         // Check line numbers are accurate.
         {"unclosed1",
                 "line1\n{{",
                 hasError, `unclosed1:2: unexpected unclosed action in command`},
         {"unclosed2",
                 "line1\n{{define `x`}}line2\n{{",
                 hasError, `unclosed2:3: unexpected unclosed action in command`},
         // Specific errors.
@@ skipping 50 matching lines @@
                 _, err := New(test.name).Parse(test.input, "", "", make(map[string]*Tree))
                 if err == nil {
                         t.Errorf("%q: expected error", test.name)
                         continue
                 }
                 if !strings.Contains(err.Error(), test.result) {
                         t.Errorf("%q: error %q does not contain %q", test.name, err, test.result)
                 }
         }
 }