1 files changed, 63 insertions, 0 deletions
diff --git a/src/cmd/gofix/httpfs.go b/src/cmd/gofix/httpfs.go
new file mode 100644
index 000000000..7f2765680
--- /dev/null
+++ b/src/cmd/gofix/httpfs.go
@@ -0,0 +1,63 @@
+// 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 main
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+var httpFileSystemFix = fix{
+	"httpfs",
+	httpfs,
+	`Adapt http FileServer to take a FileSystem.
+
+http://codereview.appspot.com/4629047  http FileSystem interface
+`,
+}
+
+func init() {
+	register(httpFileSystemFix)
+}
+
+func httpfs(f *ast.File) bool {
+	if !imports(f, "http") {
+		return false
+	}
+
+	fixed := false
+	walk(f, func(n interface{}) {
+		call, ok := n.(*ast.CallExpr)
+		if !ok || !isPkgDot(call.Fun, "http", "FileServer") {
+			return
+		}
+		if len(call.Args) != 2 {
+			return
+		}
+		dir, prefix := call.Args[0], call.Args[1]
+		call.Args = []ast.Expr{&ast.CallExpr{
+			Fun:  &ast.SelectorExpr{ast.NewIdent("http"), ast.NewIdent("Dir")},
+			Args: []ast.Expr{dir},
+		}}
+		wrapInStripHandler := true
+		if prefixLit, ok := prefix.(*ast.BasicLit); ok {
+			if prefixLit.Kind == token.STRING && (prefixLit.Value == `"/"` || prefixLit.Value == `""`) {
+				wrapInStripHandler = false
+			}
+		}
+		if wrapInStripHandler {
+			call.Fun.(*ast.SelectorExpr).Sel = ast.NewIdent("StripPrefix")
+			call.Args = []ast.Expr{
+				prefix,
+				&ast.CallExpr{
+					Fun:  &ast.SelectorExpr{ast.NewIdent("http"), ast.NewIdent("FileServer")},
+					Args: call.Args,
+				},
+			}
+		}
+		fixed = true
+	})
+	return fixed
+}