Merge pull request #137 from hairyhenderson/tojsonpretty-func

Adding new toJSONPretty function

README.md

@@ -57,6 +57,7 @@ Gomplate is an alternative that will let you process templates which also includ
 		- [`yaml`](#yaml)
 		- [`yamlArray`](#yamlarray)
 		- [`toJSON`](#tojson)
+		- [`toJSONPretty`](#tojsonpretty)
 		- [`toYAML`](#toyaml)
 		- [`datasource`](#datasource)
 		- [`datasourceExists`](#datasourceexists)
@@ -544,6 +545,26 @@ $ gomplate < input.tmpl
 {"hello":"world"}
 ```
 
+#### `toJSONPretty`
+
+Converts an object to a pretty-printed (or _indented_) JSON document. Input objects may be the result of `json`, `yaml`, `jsonArray`, or `yamlArray` functions, or they could be provided by a `datasource`.
+
+The indent string must be provided as an argument.
+
+##### Example
+
+_`input.tmpl`:_
+```
+{{ `{"hello":"world"}` | json | toJSONPretty "  " }}
+```
+
+```console
+$ gomplate < input.tmpl
+{
+  "hello": "world"
+}
+```
+
 #### `toYAML`
 
 Converts an object to a YAML document. Input objects may be the result of `json`, `yaml`, `jsonArray`, or `yamlArray` functions, or they could be provided by a `datasource`.

gomplate.go

@@ -55,6 +55,7 @@ func NewGomplate(data *Data, leftDelim, rightDelim string) *Gomplate {
 			"slice":            typeconv.Slice,
 			"join":             typeconv.Join,
 			"toJSON":           typeconv.ToJSON,
+			"toJSONPretty":     typeconv.toJSONPretty,
 			"toYAML":           typeconv.ToYAML,
 			"ec2meta":          ec2meta.Meta,
 			"ec2dynamic":       ec2meta.Dynamic,

test/integration/typeconv_funcs.bats

@@ -17,3 +17,15 @@ function teardown () {
   [ "$status" -eq 0 ]
   [[ "${output}" == "true" ]]
 }
+
+@test "toJSONPretty" {
+  gomplate -i '{{ `{"hello": "world"}` | json | toJSONPretty "   " }}
+{{ toJSONPretty "" (`{"hello": "world"}` | json) }}'
+  [ "$status" -eq 0 ]
+  [[ "${output}" == "{
+   \"hello\": \"world\"
+}
+{
+\"hello\": \"world\"
+}" ]]
+}

typeconv.go

@@ -79,6 +79,16 @@ func (t *TypeConv) ToJSON(in interface{}) string {
 	return marshalObj(in, json.Marshal)
 }
 
+// ToJSONPretty - Stringify a struct as JSON (indented)
+func (t *TypeConv) toJSONPretty(indent string, in interface{}) string {
+	b, err := json.MarshalIndent(in, "", indent)
+	if err != nil {
+		log.Fatalf("Unable to marshal object %s: %v", in, err)
+	}
+
+	return string(b)
+}
+
 // ToYAML - Stringify a struct as YAML
 func (t *TypeConv) ToYAML(in interface{}) string {
 	return marshalObj(in, yaml.Marshal)

typeconv_test.go

@@ -79,6 +79,35 @@ func TestToJSON(t *testing.T) {
 	assert.Equal(t, expected, ty.ToJSON(in))
 }
 
+func TestToJSONPretty(t *testing.T) {
+	ty := new(TypeConv)
+	expected := `{
+  "down": {
+    "the": {
+      "rabbit": {
+        "hole": true
+      }
+    }
+  },
+  "foo": "bar",
+  "one": 1,
+  "true": true
+}`
+	in := map[string]interface{}{
+		"foo":  "bar",
+		"one":  1,
+		"true": true,
+		"down": map[string]interface{}{
+			"the": map[string]interface{}{
+				"rabbit": map[string]interface{}{
+					"hole": true,
+				},
+			},
+		},
+	}
+	assert.Equal(t, expected, ty.toJSONPretty("  ", in))
+}
+
 func TestToYAML(t *testing.T) {
 	ty := new(TypeConv)
 	expected := `d: 2006-01-02T15:04:05.999999999-07:00