feat: include support for json5 encoding

JSON5 is a superset of JSON, which includes support for trailing commas,
extra whitespaces, comments, and an expanded set of numbers. This commit
adds mainly decoding support for json5, in `@lune/serde`. Encoding
"support" is also included, but isn't a practical use-case.

* Expanded `EncodeDecodeFormat` to have a `Json5` variant
* Handled JSON5 decoding using `serde_json5` crate
* Matched JSON5 encoding alongside JSON

Cargo.lock

@@ -1134,6 +1134,7 @@ dependencies = [
  "rustyline",
  "serde",
  "serde_json",
+ "serde_json5",
  "serde_yaml",
  "thiserror",
  "tokio",
@@ -1394,6 +1395,51 @@ version = "2.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
+[[package]]
+name = "pest"
+version = "2.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "219c0dcc30b6a27553f9cc242972b67f75b60eb0db71f0b5462f38b058c41546"
+dependencies = [
+ "memchr",
+ "thiserror",
+ "ucd-trie",
+]
+
+[[package]]
+name = "pest_derive"
+version = "2.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22e1288dbd7786462961e69bfd4df7848c1e37e8b74303dbdab82c3a9cdd2809"
+dependencies = [
+ "pest",
+ "pest_generator",
+]
+
+[[package]]
+name = "pest_generator"
+version = "2.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1381c29a877c6d34b8c176e734f35d7f7f5b3adaefe940cb4d1bb7af94678e2e"
+dependencies = [
+ "pest",
+ "pest_meta",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
+[[package]]
+name = "pest_meta"
+version = "2.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0934d6907f148c22a3acbda520c7eed243ad7487a30f51f6ce52b58b7077a8a"
+dependencies = [
+ "once_cell",
+ "pest",
+ "sha2",
+]
+
 [[package]]
 name = "pin-project"
 version = "1.1.3"
@@ -1992,6 +2038,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_json5"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a6b754515e1a7bd79fc2edeaecee526fc80cb3a918607e5ca149225a3a9586"
+dependencies = [
+ "pest",
+ "pest_derive",
+ "serde",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "0.6.5"
@@ -2052,6 +2109,17 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
 
+[[package]]
+name = "sha2"
+version = "0.10.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "793db75ad2bcafc3ffa7c68b215fee268f537982cd901d132f89c6343f3a3dc8"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
 [[package]]
 name = "sharded-slab"
 version = "0.1.7"
@@ -2568,6 +2636,12 @@ version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
+[[package]]
+name = "ucd-trie"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed646292ffc8188ef8ea4d1e0e0150fb15a5c2e12ad9b8fc191ae7a8a7f3c4b9"
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.14"

Cargo.toml

@@ -96,6 +96,7 @@ async-compression = { version = "0.4", features = [
 ] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = { version = "1.0", features = ["preserve_order"] }
+serde_json5 = { version = "0.1.0" }
 serde_yaml = "0.9"
 toml = { version = "0.8", features = ["preserve_order"] }
 

src/lune/builtins/serde/encode_decode.rs

@@ -17,6 +17,7 @@ const LUA_DESERIALIZE_OPTIONS: LuaDeserializeOptions = LuaDeserializeOptions::ne
 #[derive(Debug, Clone, Copy)]
 pub enum EncodeDecodeFormat {
     Json,
+    Json5,
     Yaml,
     Toml,
 }
@@ -26,13 +27,14 @@ impl<'lua> FromLua<'lua> for EncodeDecodeFormat {
         if let LuaValue::String(s) = &value {
             match s.to_string_lossy().to_ascii_lowercase().trim() {
                 "json" => Ok(Self::Json),
+                "json5" => Ok(Self::Json5),
                 "yaml" => Ok(Self::Yaml),
                 "toml" => Ok(Self::Toml),
                 kind => Err(LuaError::FromLuaConversionError {
                     from: value.type_name(),
                     to: "EncodeDecodeFormat",
                     message: Some(format!(
-                        "Invalid format '{kind}', valid formats are:  json, yaml, toml"
+                        "Invalid format '{kind}', valid formats are:  json, json5, yaml, toml"
                     )),
                 }),
             }
@@ -59,7 +61,10 @@ impl EncodeDecodeConfig {
         value: LuaValue<'lua>,
     ) -> LuaResult<LuaString<'lua>> {
         let bytes = match self.format {
-            EncodeDecodeFormat::Json => {
+            // Encoding to Json5 is impractical, since it only includes support for
+            // things like trailing commas, comments, etc. which provide convenience
+            // for humans
+            EncodeDecodeFormat::Json | EncodeDecodeFormat::Json5 => {
                 let serialized: JsonValue = lua.from_value_with(value, LUA_DESERIALIZE_OPTIONS)?;
                 if self.pretty {
                     serde_json::to_vec_pretty(&serialized).into_lua_err()?
@@ -97,6 +102,10 @@ impl EncodeDecodeConfig {
                 let value: JsonValue = serde_json::from_slice(bytes).into_lua_err()?;
                 lua.to_value_with(&value, LUA_SERIALIZE_OPTIONS)
             }
+            EncodeDecodeFormat::Json5 => {
+                let value: JsonValue = serde_json5::from_slice(bytes).into_lua_err()?;
+                lua.to_value_with(&value, LUA_SERIALIZE_OPTIONS)
+            }
             EncodeDecodeFormat::Yaml => {
                 let value: YamlValue = serde_yaml::from_slice(bytes).into_lua_err()?;
                 lua.to_value_with(&value, LUA_SERIALIZE_OPTIONS)