fix(templating)!: return json, not go structs

docs/fields.md

@@ -127,6 +127,8 @@ Workflow is the definition of a workflow resource
 
 - [`exit-handlers.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handlers.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -565,6 +567,8 @@ WorkflowSpec is the specification of a Workflow.
 
 - [`exit-handlers.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handlers.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -1004,6 +1008,8 @@ CronWorkflowSpec is the specification of a CronWorkflow
 
 - [`exit-handlers.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handlers.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -1333,6 +1339,8 @@ Arguments to a template
 
 - [`exit-handler-with-param.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handler-with-param.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -2131,6 +2139,8 @@ Parameter indicate a passed string parameter to a service template with an optio
 
 - [`exit-handler-with-param.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handler-with-param.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -2677,6 +2687,8 @@ Inputs are the mechanism for passing parameters, artifacts, volumes from one tem
 
 - [`exit-handler-with-param.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handler-with-param.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -2878,6 +2890,8 @@ ScriptTemplate is a template subtype to enable scripting through code steps
 
 - [`exit-handler-with-param.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handler-with-param.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -3909,6 +3923,8 @@ DataSource sources external data into a data template
 
 - [`exit-handler-with-param.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handler-with-param.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -4659,6 +4675,8 @@ ObjectMeta is metadata that all persisted resources must have, which includes al
 
 - [`exit-handlers.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handlers.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -5572,6 +5590,8 @@ EnvVar represents an environment variable present in a Container.
 
 - [`colored-logs.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/colored-logs.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)
@@ -5990,6 +6010,8 @@ PersistentVolumeClaimSpec describes the common attributes of storage devices and
 
 - [`exit-handlers.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/exit-handlers.yaml)
 
+- [`expression-destructure-json-complex.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json-complex.yaml)
+
 - [`expression-destructure-json.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-destructure-json.yaml)
 
 - [`expression-reusing-verbose-snippets.yaml`](https://github.com/argoproj/argo-workflows/blob/main/examples/expression-reusing-verbose-snippets.yaml)

examples/expression-destructure-json-complex.yaml

@@ -0,0 +1,36 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  generateName: expression-destructure-json-complex-
+spec:
+  arguments:
+    parameters:
+      - name: config
+        value: '{"employees": [{"name": "Baris", "age":43},{"name": "Mo", "age": 42}, {"name": "Jai", "age" :44}]}'
+  entrypoint: main
+  templates:
+    - name: main
+      inputs:
+        parameters:
+          - name: a
+            value: "{{=jsonpath(workflow.parameters.config, '$.employees[?(@.name==\"Baris\")].age')}}"
+          - name: b
+            value: "{{=jsonpath(workflow.parameters.config, '$.employees[?(@.age>42 && @.age<44)].age')}}"
+          - name: c
+            value: "{{=jsonpath(workflow.parameters.config, '$.employees[0:1]')}}"
+          - name: d
+            value: "{{=jsonpath(workflow.parameters.config, '$.employees[*].name')}}"
+      script:
+        env:
+          - name: A
+            value: "{{inputs.parameters.a}}"
+          - name: B
+            value: "{{inputs.parameters.b}}"
+          - name: C
+            value: "{{inputs.parameters.c}}"
+          - name: D
+            value: "{{inputs.parameters.d}}"
+        image: debian:9.4
+        command: [bash]
+        source: |
+          echo "$A$B$C$D"

util/template/expression_template.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 	"strings"
 
 	"github.com/doublerebel/bellows"
@@ -69,7 +70,7 @@ func expressionReplace(w io.Writer, expression string, env map[string]interface{
 	if result == nil {
 		return 0, fmt.Errorf("failed to evaluate expression %q", expression)
 	}
-	resultMarshaled, err := json.Marshal(fmt.Sprintf("%v", result))
+	resultMarshaled, err := json.Marshal(result)
 	if (err != nil || resultMarshaled == nil) && allowUnresolved {
 		log.WithError(err).Debug("resultMarshaled is nil and unresolved is allowed ")
 		return w.Write([]byte(fmt.Sprintf("{{%s%s}}", kindExpression, expression)))
@@ -80,9 +81,20 @@ func expressionReplace(w io.Writer, expression string, env map[string]interface{
 	if resultMarshaled == nil {
 		return 0, fmt.Errorf("failed to marshal evaluated marshaled expression %q", expression)
 	}
-	// Trim leading and trailing quotes. The value is being inserted into something that's already a string.
 	marshaledLength := len(resultMarshaled)
-	return w.Write(resultMarshaled[1 : marshaledLength-1])
+
+	// Trim leading and trailing quotes. The value is being inserted into something that's already a string.
+	if len(resultMarshaled) > 1 && resultMarshaled[0] == '"' && resultMarshaled[marshaledLength-1] == '"' {
+		return w.Write(resultMarshaled[1 : marshaledLength-1])
+	}
+
+	// Check if the value contains any quotes by adding double quotes at the beginning and end of the value.
+	// If so then escape quotes.
+	if !json.Valid([]byte(`"` + string(resultMarshaled) + `"`)) {
+		resultQuoted := []byte(strconv.Quote(string(resultMarshaled)))
+		return w.Write(resultQuoted[1 : len(resultQuoted)-1])
+	}
+	return w.Write(resultMarshaled)
 }
 
 func EnvMap(replaceMap map[string]string) map[string]interface{} {

util/template/template_test.go

@@ -65,4 +65,25 @@ func Test_Template_Replace(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("ExpressionWithJsonPath", func(t *testing.T) {
+		testCases := map[string]struct {
+			input, want string
+		}{
+			"ExprNumArrayOutput":      {input: `{{=jsonpath('{"employees": [{"name": "Baris", "age":43, "friends": ["Mo", "Jai"]}, {"name": "Mo", "age": 42, "friends": ["Baris", "Jai"]}, {"name": "Jai", "age" :44, "friends": ["Baris", "Mo"]}]}', '$.employees[*].name')}}`, want: "[\"Baris\",\"Mo\",\"Jai\"]"},
+			"ExprStringArrayOutput":   {input: `{{=jsonpath('{"employees": [{"name": "Baris", "age":43, "friends": ["Mo", "Jai"]}, {"name": "Mo", "age": 42, "friends": ["Baris", "Jai"]}, {"name": "Jai", "age" :44, "friends": ["Baris", "Mo"]}]}', '$.employees[0].friends')}}`, want: "[\"Mo\",\"Jai\"]"},
+			"ExprSimpleObjectOutput":  {input: `{{=jsonpath('{"employees": [{"name": "Baris", "age":43},{"name": "Mo", "age": 42}, {"name": "Jai", "age" :44}]}', '$.employees[0]')}}`, want: "{\"age\":43,\"name\":\"Baris\"}"},
+			"ExprObjectArrayOutput":   {input: `{{=jsonpath('{"employees": [{"name": "Baris", "age":43},{"name": "Mo", "age": 42}, {"name": "Jai", "age" :44}]}', '$')}}`, want: "{\"employees\":[{\"age\":43,\"name\":\"Baris\"},{\"age\":42,\"name\":\"Mo\"},{\"age\":44,\"name\":\"Jai\"}]}"},
+			"ExprArrayInObjectOutput": {input: `{{=jsonpath('{"employees": [{"name": "Baris", "age":43, "friends": ["Mo", "Jai"]}, {"name": "Mo", "age": 42, "friends": ["Baris", "Jai"]}, {"name": "Jai", "age" :44, "friends": ["Baris", "Mo"]}]}', '$.employees[0]')}}`, want: "{\"age\":43,\"friends\":[\"Mo\",\"Jai\"],\"name\":\"Baris\"}"},
+		}
+
+		for name, tc := range testCases {
+			t.Run(name, func(t *testing.T) {
+				tmpl := SimpleValue{Value: tc.input}
+				newTmpl := processTemplate(t, tmpl, map[string]string{})
+				assert.Equal(t, tc.want, newTmpl.Value)
+			})
+		}
+	})
+
 }