Add JsonNode support & enhance JsonElement

README.md

@@ -103,6 +103,42 @@ var result = template(data); // "6"
 
 This is a C#-specific capability, since JavaScript/Handlebars.js has no equivalent to true multi-dimensional arrays.
 
+### System.Text.Json
+
+`System.Text.Json` values can be passed to a template directly, with no conversion to POCOs or dictionaries.
+
+**`JsonElement`**: deserializing JSON as `object` with `JsonSerializer.Deserialize<object>(json)` gives you a `JsonElement`. You can pass that in, or any other `JsonElement` such as `JsonDocument.RootElement`.
+
+**`JsonNode`**: `JsonObject`, `JsonArray` and `JsonValue` work too, whether they come from `JsonNode.Parse` or are built in code. A node tree is read when the template renders, so changes made to it between renders show up in the output.
+
+```c#
+var template = Handlebars.Compile("{{title}}: {{#each tags}}{{@index}}={{this}} {{/each}}{{#if draft}}(draft){{/if}}");
+
+var json = @"{ ""title"": ""My post"", ""tags"": [""a"", ""b""], ""draft"": false }";
+
+template(JsonSerializer.Deserialize<object>(json)); // "My post: 0=a 1=b "
+template(JsonNode.Parse(json));                     // "My post: 0=a 1=b "
+
+var data = new JsonObject
+{
+    ["title"] = "My post",
+    ["tags"] = new JsonArray("a", "b"),
+    ["draft"] = true
+};
+
+template(data); // "My post: 0=a 1=b (draft)"
+```
+
+For both types:
+- Properties are matched by exact name first, then by the lowercase name, so `{{Title}}` finds a `"title"` property.
+- Arrays support index access (`{{tags.[0]}}`), `{{tags.Count}}`, and `#each` with `@index`, `@first` and `@last`. Objects support `#each` with `@key`.
+- As with other collections, `{{tags.length}}` works once `handlebars.Configuration.UseCollectionMemberAliasProvider()` is enabled.
+- `#if`, `#unless` and `#each` treat `false`, `null`, `0`, `""`, `[]` and `{}` as falsy. Pass `includeZero=true` to `#if` to treat `0` as truthy.
+
+When interpolated directly, booleans render as `True`/`False` for `JsonElement` and `true`/`false` for `JsonNode`.
+
+Compatibility: `JsonNode` values `false`, `0`, and `""` now follow falsy semantics; `JsonObject` lookups now include the lowercase fallback described above; custom member alias providers are now consulted for unresolved `JsonElement` and `JsonObject` members.
+
 ### Registering Partials
 
 ```c#

source/Handlebars.Test/DynamicTests.cs

@@ -5,7 +5,6 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
-using System.Text.Json;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
@@ -301,116 +300,6 @@ public void WithParentIndexJsonNet(IHandlebars handlebars)
             Assert.Equal( makeFlat( expected ), makeFlat( result ) );
         }
 
-        // System.Text.Json's JsonElement (the result of System.Text.Json.JsonSerializer.Deserialize<object>) has no
-        // built-in support for member access/iteration in .NET, unlike Newtonsoft's JObject/JToken
-        // above. These tests mirror the JObject coverage to ensure feature parity between the two.
-        [Fact]
-        public void JsonElementResolvesNestedProperty()
-        {
-            var json = "{\"A\": {\"B\": \"b\"}}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{A.B}}");
-
-            Assert.Equal("b", template(data));
-        }
-
-        [Fact]
-        public void JsonElementRendersScalarPropertyValues()
-        {
-            var json = "{\"str\": \"hello\", \"num\": 42, \"nothing\": null}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{str}}|{{num}}|{{nothing}}");
-
-            Assert.Equal("hello|42|", template(data));
-        }
-
-        [Fact]
-        public void JsonElementIteratesArray()
-        {
-            var json = "{\"items\": [1, 2, 3]}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{#each items}}{{this}},{{/each}}");
-
-            Assert.Equal("1,2,3,", template(data));
-        }
-
-        [Fact]
-        public void JsonElementIteratesArrayOfObjects()
-        {
-            var json = "{\"items\": [{\"Name\": \"a\"}, {\"Name\": \"b\"}]}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{#each items}}{{Name}},{{/each}}");
-
-            Assert.Equal("a,b,", template(data));
-        }
-
-        [Fact]
-        public void JsonElementIteratesObjectProperties()
-        {
-            var json = "{\"A\": \"1\", \"B\": \"2\"}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{#each this}}{{@key}}={{this}} {{/each}}");
-
-            Assert.Equal("A=1 B=2 ", template(data));
-        }
-
-        [Theory]
-        [InlineData("{\"flag\": true}", "yes")]
-        [InlineData("{\"flag\": false}", "no")]
-        public void JsonElementBooleanRespectsTruthiness(string json, string expected)
-        {
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{#if flag}}yes{{else}}no{{/if}}");
-
-            Assert.Equal(expected, template(data));
-        }
-
-        [Fact]
-        public void JsonElementTreatsEmptyStringNullAndZeroAsFalsy()
-        {
-            var json = "{\"empty\": \"\", \"nothing\": null, \"zero\": 0}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile(
-                "{{#if empty}}T{{else}}F{{/if}}" +
-                "{{#if nothing}}T{{else}}F{{/if}}" +
-                "{{#if zero}}T{{else}}F{{/if}}"
-            );
-
-            Assert.Equal("FFF", template(data));
-        }
-
-        [Fact]
-        public void JsonElementTreatsEmptyArrayAndObjectAsFalsy()
-        {
-            var json = "{\"emptyArr\": [], \"emptyObj\": {}}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile(
-                "{{#if emptyArr}}T{{else}}F{{/if}}" +
-                "{{#if emptyObj}}T{{else}}F{{/if}}"
-            );
-
-            Assert.Equal("FF", template(data));
-        }
-
-        [Fact]
-        public void JsonElementReturnsEmptyForMissingProperty()
-        {
-            var json = "{\"A\": \"a\"}";
-            object data = System.Text.Json.JsonSerializer.Deserialize<object>(json)!;
-
-            var template = Handlebars.Create().Compile("{{Missing.Nested}}");
-
-            Assert.Equal("", template(data));
-        }
-
 #if NET452 || NET46 || NET461 || NET472
 
         [Fact]
@@ -449,4 +338,3 @@ public override bool TryGetMember(GetMemberBinder binder, out object result)
         }
     }
 }
-