Allow Complex JSON as Template input

Previously nested and array JSON was converted to flat dictionary.

Author: Sefriol

src/IotTelemetrySimulator/RunnerConfiguration.cs

@@ -9,6 +9,7 @@
     using Microsoft.Extensions.Configuration;
     using Microsoft.Extensions.Logging;
     using Newtonsoft.Json;
+    using Newtonsoft.Json.Linq;
 
     public class RunnerConfiguration
     {
@@ -450,26 +451,37 @@ private static string GetTemplateFromSection(IConfigurationSection subSection, s
                 return valueString;
             }
 
-            var dictionaryVals = new Dictionary<string, string>();
-            ConvertToDictionary(templateConfigSection, dictionaryVals, templateConfigSection);
-
-            return JsonConvert.SerializeObject(dictionaryVals);
+            return JsonConvert.SerializeObject(ConvertToJToken(templateConfigSection));
         }
 
-        static void ConvertToDictionary(IConfigurationSection configuration, Dictionary<string, string> data, IConfigurationSection top = null)
+        // Implemention from https://stackoverflow.com/a/62533775
+        private static JToken ConvertToJToken(IConfiguration config)
         {
-            var children = configuration.GetChildren();
-            foreach (var child in children)
+            JObject obj = new JObject();
+
+            foreach (var child in config.GetChildren())
             {
-                if (child.Value == null)
+                if (child.Path.EndsWith(":0"))
                 {
-                    ConvertToDictionary(configuration.GetSection(child.Key), data, configuration);
-                    continue;
+                    var arr = new JArray();
+
+                    foreach (var arrayChild in config.GetChildren())
+                    {
+                        arr.Add(ConvertToJToken(arrayChild));
+                    }
+
+                    return arr;
                 }
 
-                var key = top != null ? child.Path.Substring(top.Path.Length + 1) : child.Path;
-                data[key] = child.Value;
+                obj.Add(child.Key, ConvertToJToken(child));
             }
+
+            if (!obj.HasValues && config is IConfigurationSection section)
+            {
+                return new JValue(section.Value);
+            }
+
+            return obj;
         }
     }
 }

test/IotTelemetrySimulator.Test/IotTelemetrySimulator.Test.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
@@ -32,6 +32,9 @@
     <AdditionalFiles Include="../../stylecop.json" Link="stylecop.json" />
   </ItemGroup>
   <ItemGroup>
+    <None Update="test_files\test9-config-array-template.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="test_files\test5-config-payloads-as-json.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>

test/IotTelemetrySimulator.Test/RunnerConfigurationTest.cs

@@ -296,5 +296,21 @@ public void When_DeviceSpecific_Interval_Is_Not_Positive_Number_Should_Throw(str
 
             Assert.Throws<ConfigurationErrorsException>(() => RunnerConfiguration.Load(configuration, NullLogger.Instance));
         }
+
+        [Fact]
+        public void When_Payload_Array_Template_Loads_Correctly()
+        {
+            var configuration = new ConfigurationBuilder()
+                .AddJsonFile("./test_files/test9-config-array-template.json", false, false)
+                .Build();
+
+            var target = RunnerConfiguration.Load(configuration, NullLogger.Instance);
+            var templatedPayload = Assert.IsType<TemplatedPayload>(target.PayloadGenerator.Payloads[0]);
+            Assert.Equal(1, templatedPayload.Variables.Variables.Count);
+            Assert.True(templatedPayload.Variables.Variables[0].Sequence);
+            Assert.Equal("device0001", templatedPayload.DeviceId);
+            Assert.Equal(new[] { "Counter" }, templatedPayload.Variables.Variables[0].GetReferenceVariableNames());
+            Assert.Equal("[{\"value1\":{\"value2\":\"$.Value\"}}]", templatedPayload.Template.ToString());
+        }
     }
 }

test/IotTelemetrySimulator.Test/test_files/test9-config-array-template.json

@@ -0,0 +1,16 @@
+{
+  "Variables": [
+    {
+      "name": "Value",
+      "sequence": true,
+      "values": [ "$.Counter", "true" ]
+    }
+  ],
+  "Payloads": [
+    {
+      "type": "template",
+      "deviceId": "device0001",
+      "template": [{"value1": {"value2": "$.Value" } }]
+    }
+  ]
+}