From ca5b4c0016926bbadef467e81c9642610d8ee59d Mon Sep 17 00:00:00 2001
From: Marcel Ludwig <marcel.ludwig@avenga.com>
Date: Fri, 23 Oct 2020 15:04:07 +0200
Subject: [PATCH] Fix a panic for unknown cty types, return cty.NullVal of type
 cty.String as fallback #44

Add test for json 'null' values
---
 eval/context_test.go       |  6 +++++-
 internal/seetie/convert.go | 14 +++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/eval/context_test.go b/eval/context_test.go
index 385ed7d26..47713492c 100644
--- a/eval/context_test.go
+++ b/eval/context_test.go
@@ -78,6 +78,10 @@ func TestNewHTTPContext(t *testing.T) {
 			method = req.method
 			title = req.json_body.slice.foo
 		`, http.Header{"method": {http.MethodGet}}},
+		{"Variables / GET /w json body & null value", http.MethodGet, http.Header{"Content-Type": {"application/json"}}, bytes.NewBufferString(`{"json": null}`), "", baseCtx, `
+			method = req.method
+			title = req.json_body.json
+		`, http.Header{"method": {http.MethodGet}, "title": {""}}},
 	}
 
 	log, _ := test.NewNullLogger()
@@ -134,7 +138,7 @@ func TestNewHTTPContext(t *testing.T) {
 
 				result := seetie.ValueToStringSlice(cv)
 				if !reflect.DeepEqual(v, result) {
-					t.Errorf("Expected %q, got: %v", v, cv)
+					t.Errorf("Expected %q, got: %#v", v, cv)
 				}
 			}
 		})
diff --git a/internal/seetie/convert.go b/internal/seetie/convert.go
index 05051a809..1184b0601 100644
--- a/internal/seetie/convert.go
+++ b/internal/seetie/convert.go
@@ -5,7 +5,6 @@ import (
 	"math/big"
 	"net/http"
 	"net/url"
-	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
@@ -81,7 +80,7 @@ func GoToValue(v interface{}) cty.Value {
 	case map[string]interface{}:
 		return MapToValue(v.(map[string]interface{}))
 	}
-	return cty.NilVal
+	return cty.NullVal(cty.String)
 }
 
 func MapToValue(m map[string]interface{}) cty.Value {
@@ -96,8 +95,6 @@ func MapToValue(m map[string]interface{}) cty.Value {
 			continue
 		}
 		switch v.(type) {
-		case bool, float64, string:
-			ctyMap[k] = GoToValue(v)
 		case []string:
 			var list []interface{}
 			for _, s := range v.([]string) {
@@ -109,7 +106,7 @@ func MapToValue(m map[string]interface{}) cty.Value {
 		case map[string]interface{}:
 			ctyMap[k] = MapToValue(v.(map[string]interface{}))
 		default:
-			panic(reflect.TypeOf(v).String() + " not implemented")
+			ctyMap[k] = GoToValue(v)
 		}
 	}
 
@@ -168,6 +165,10 @@ var whitespaceRegex = regexp.MustCompile(`^\s*$`)
 // ValueToString explicitly drops all other (unknown) types and
 // converts non whitespace strings or numbers to its string representation.
 func ValueToString(v cty.Value) string {
+	if v.IsNull() {
+		return ""
+	}
+
 	switch v.Type() {
 	case cty.String:
 		str := v.AsString()
@@ -221,6 +222,9 @@ func ToString(s interface{}) string {
 
 // isTuple checks by type name since tuple is not comparable by type.
 func isTuple(v cty.Value) bool {
+	if v.IsNull() {
+		return false
+	}
 	return v.Type().FriendlyNameForConstraint() == "tuple"
 }