Template handler to get json objects by path

Author: hareekum

README.md

@@ -279,10 +279,12 @@ OpenMock leverages [https://golang.org/pkg/text/template/](https://golang.org/pk
   ```bash
   # Supported functions defined in ./template_helper.go
 
-    - jsonPath # doc: https://github.com/antchfx/xpath
-    - xmlPath  # doc: https://github.com/antchfx/xpath
-    - uuidv5   # uuid v5 sha1 hash
-    - redisDo  # run redis commands. For example {{redisDo "RPUSH" "arr" "hi"}}
+    - 
+    - jsonPath    # doc: https://github.com/antchfx/xpath
+    - gJsonPath   # doc: https://github.com/tidwall/gjson
+    - xmlPath     # doc: https://github.com/antchfx/xpath
+    - uuidv5      # uuid v5 sha1 hash
+    - redisDo     # run redis commands. For example {{redisDo "RPUSH" "arr" "hi"}}
     - ...
 
   # Supported functions inherited from
@@ -296,6 +298,7 @@ OpenMock leverages [https://golang.org/pkg/text/template/](https://golang.org/pk
   # Examples
   {{.HTTPHeader.Get "X-Token" | eq "t1234"}}
   {{.HTTPBody | jsonPath "user/first_name" | replace "A" "a" | uuidv5 }}
+  {{.HTTPBody | gJsonPath "users.0.first_name" }}
   {{.HTTPBody | xmlPath "node1/node2/node3"}}
   ```
 
@@ -602,7 +605,7 @@ with the `proto.MessageV2` method.
 
 Please note that OpenMock expects the `payload` or `payload_from_file` for a reply_grpc action to be in the json
 form of your `Response` protobuf message.  The request should be in the `Request` protobuf message format
-as it is parsed into json to support JSONPath operations.
+as it is parsed into json to support `jsonPath` and `gJsonPath` operations.
 
 Example configuration by directly importing the `github.com/checkr/openmock` package into a wrapper project.
 ```

demo_templates/http.yaml

@@ -194,6 +194,18 @@
         status_code: 200
         body: '{{ .HTTPBody | jsonPath "foo" }}'
 
+- key: json-payload-from-http-body
+  kind: Behavior
+  expect:
+    condition: '{{ .HTTPBody | gJsonPath "context.type" | toString | eq "foo" }}'
+    http:
+      method: POST
+      path: /json_from_body
+  actions:
+    - reply_http:
+        status_code: 200
+        body: '{{ .HTTPBody | gJsonPath "context.payload" }}'
+
 - key: base64-basicauth-with-env
   kind: Behavior
   expect:

go.mod

@@ -56,6 +56,8 @@ require (
 	github.com/streadway/amqp v0.0.0-20180806233856-70e15c650864
 	github.com/stretchr/testify v1.5.1
 	github.com/teamwork/reload v1.3.0
+	github.com/tidwall/gjson v1.6.0
+	github.com/tidwall/pretty v1.0.1 // indirect
 	github.com/yuin/gopher-lua v0.0.0-20180827083657-b942cacc89fe // indirect
 	golang.org/x/net v0.0.0-20200226121028-0de0cce0169b
 	google.golang.org/genproto v0.0.0-20200224152610-e50cd9704f63 // indirect

go.sum

@@ -270,8 +270,14 @@ github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/teamwork/reload v1.3.0 h1:ElBaBhtRwVRxsPRGK1wYugr2knciOXFMZT5ltPpEwAI=
 github.com/teamwork/reload v1.3.0/go.mod h1:kHdVPdfdmA+ygkBbigWUeerpy6EK4Kcukx1TNyePXHA=
+github.com/tidwall/gjson v1.6.0 h1:9VEQWz6LLMUsUl6PueE49ir4Ka6CzLymOAZDxpFsTDc=
+github.com/tidwall/gjson v1.6.0/go.mod h1:P256ACg0Mn+j1RXIDXoss50DeIABTYK1PULOJHhxOls=
+github.com/tidwall/match v1.0.1 h1:PnKP62LPNxHKTwvHHZZzdOAOCtsJTjo6dZLCwpKm5xc=
+github.com/tidwall/match v1.0.1/go.mod h1:LujAq0jyVjBy028G1WhWfIzbpQfMO8bBZ6Tyb0+pL9E=
 github.com/tidwall/pretty v1.0.0 h1:HsD+QiTn7sK6flMKIvNmpqz1qrpP3Ps6jOKIKMooyg4=
 github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=
+github.com/tidwall/pretty v1.0.1 h1:WE4RBSZ1x6McVVC8S/Md+Qse8YUv6HRObAx6ke00NY8=
+github.com/tidwall/pretty v1.0.1/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=

template_helper.go

@@ -4,6 +4,7 @@ import (
 	"crypto/hmac"
 	"crypto/sha256"
 	"encoding/hex"
+	"errors"
 	"reflect"
 	"regexp"
 	"strings"
@@ -13,13 +14,15 @@ import (
 	"github.com/antchfx/xmlquery"
 	"github.com/google/uuid"
 	"github.com/sirupsen/logrus"
+	"github.com/tidwall/gjson"
 )
 
 func genLocalFuncMap(om *OpenMock) template.FuncMap {
 	return template.FuncMap{
 		"htmlEscapeString":       template.HTMLEscapeString,
 		"isLastIndex":            isLastIndex,
 		"jsonPath":               jsonPath,
+		"gJsonPath":              gJsonPath,
 		"redisDo":                redisDo(om),
 		"regexFindAllSubmatch":   regexFindAllSubmatch,
 		"regexFindFirstSubmatch": regexFindFirstSubmatch,
@@ -56,6 +59,36 @@ func jsonPath(expr string, tmpl string) (ret string, err error) {
 	return "", nil
 }
 
+func gJsonPath(expr string, tmpl string) (ret string, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = r.(error)
+		}
+		logrus.WithFields(logrus.Fields{
+			"err":  err,
+			"tmpl": tmpl,
+			"expr": expr,
+		}).Debug("running gJsonPath")
+	}()
+
+	if tmpl == "" {
+		return "", nil
+	}
+
+	if !gjson.Valid(tmpl) {
+		return "", errors.New("Invalid json")
+	}
+
+	node := gjson.Parse(tmpl).Get(expr)
+	if node.Exists() {
+		if node.Type.String() == "String" {
+			return node.String(), nil
+		}
+		return node.Raw, nil
+	}
+	return "", nil
+}
+
 func xmlPath(expr string, tmpl string) (ret string, err error) {
 	defer func() {
 		if r := recover(); r != nil {

template_helper_test.go

@@ -47,6 +47,62 @@ func TestJSONPath(t *testing.T) {
 	assert.Equal(t, "112879785776", ret)
 }
 
+func TestGJsonPath(t *testing.T) {
+	var tmpl string
+	var ret string
+	var err error
+
+	tmpl = `{"payload": {"user": {"username": "johnny", "first_name": "John", "valid": true, "id": 7, "profile": null}}}`
+
+	ret, err = gJsonPath("payload.user", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "{\"username\": \"johnny\", \"first_name\": \"John\", \"valid\": true, \"id\": 7, \"profile\": null}", ret)
+
+	ret, err = gJsonPath("payload.user.first_name", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "John", ret)
+
+	ret, err = gJsonPath("payload.user.valid", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "true", ret)
+
+	ret, err = gJsonPath("payload.user.id", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "7", ret)
+
+	ret, err = gJsonPath("payload.user.profile", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "null", ret)
+
+	tmpl = `{"payload": {"rivers": ["klamath", "merced", "american", "mississippi"]}}`
+
+	ret, err = gJsonPath("payload.rivers.#", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "4", ret)
+
+	ret, err = gJsonPath("payload.rivers.1", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "merced", ret)
+
+	ret, err = gJsonPath("payload.riv*.2", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "american", ret)
+
+	ret, err = gJsonPath("payload.r?vers.0", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "klamath", ret)
+
+	tmpl = `{"payload": {"rivers": [{"name": "klamath", "length": 257}, {"name": "merced", "length": 145}]}}`
+	ret, err = gJsonPath("payload.rivers.#.length", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "[257,145]", ret)
+
+	tmpl = `{"payload": {"rivers": [{"name": "klamath", "length": 257}, {"name": "merced", "length": 145}]}}`
+	ret, err = gJsonPath("payload.rivers.1.name", tmpl)
+	assert.NoError(t, err)
+	assert.Equal(t, "merced", ret)
+}
+
 func TestHelpers(t *testing.T) {
 	t.Run("uuid4 helpers", func(t *testing.T) {
 		raw := `{{ uuidv4 }}`

template_test.go

@@ -35,7 +35,8 @@ func TestTemplateRender(t *testing.T) {
 		raw := `{
 				"transaction_id": "{{.KafkaPayload | jsonPath "transaction_id"}}",
 				"first_name": "{{.AMQPPayload | xmlPath "user/first_name"}}",
-				"middle_name": "{{.HTTPBody | jsonPath "user/middle_name"}}"
+				"middle_name": "{{.HTTPBody | jsonPath "user/middle_name"}}",
+				"user": {{.HTTPBody | gJsonPath "user"}}
 				}`
 		c := Context{
 			HTTPBody:     `{"user": {"middle_name": "H"}}`,
@@ -49,7 +50,8 @@ func TestTemplateRender(t *testing.T) {
 			{
 				"transaction_id": "t1234",
 				"first_name": "John",
-				"middle_name": "H"
+				"middle_name": "H",
+				"user": {"middle_name": "H"}
 			}
 		`)
 	})