tpl: Add debug.Dump

Fixes #3957

tpl/debug/debug.go

@@ -0,0 +1,40 @@
+// Copyright 2020 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package debug provides template functions to help debugging templates.
+package debug
+
+import (
+	"github.com/sanity-io/litter"
+
+	"github.com/gohugoio/hugo/deps"
+)
+
+// New returns a new instance of the debug-namespaced template functions.
+func New(d *deps.Deps) *Namespace {
+	return &Namespace{}
+}
+
+// Namespace provides template functions for the "debug" namespace.
+type Namespace struct {
+}
+
+// Dump returns a object dump of val as a string.
+// Note that not every value passed to Dump will print so nicely, but
+// we'll improve on that. We recommend using the "go" Chroma lexer to format the output
+// nicely.
+// Also note that the output from Dump may change from Hugo version to the next,
+// so don't depend on a specific output.
+func (ns *Namespace) Dump(val interface{}) string {
+	return litter.Sdump(val)
+}