Support jsonc format

Cargo.toml

@@ -126,8 +126,9 @@ json = ["serde_json"]
 yaml = ["yaml-rust2"]
 ini = ["rust-ini"]
 json5 = ["json5_rs", "dep:serde-untagged"]
+jsonc = ["dep:jsonc-parser"]
 convert-case = ["convert_case"]
-preserve_order = ["indexmap", "toml?/preserve_order", "serde_json?/preserve_order", "ron?/indexmap"]
+preserve_order = ["indexmap", "toml?/preserve_order", "serde_json?/preserve_order", "jsonc-parser?/preserve_order", "ron?/indexmap"]
 async = ["async-trait"]
 toml = ["dep:toml"]
 
@@ -141,6 +142,7 @@ yaml-rust2 = { version = "0.10", optional = true }
 rust-ini = { version = "0.21", optional = true }
 ron = { version = "0.8", optional = true }
 json5_rs = { version = "0.4", optional = true, package = "json5" }
+jsonc-parser = { version = "0.26.3", optional = true }
 indexmap = { version = "2.10.0", features = ["serde"], optional = true }
 convert_case = { version = "0.6", optional = true }
 pathdiff = "0.2"

README.md

@@ -11,7 +11,7 @@
 
  - Set defaults
  - Set explicit values (to programmatically override)
- - Read from [JSON], [TOML], [YAML], [INI], [RON], [JSON5] files
+ - Read from [JSON], [TOML], [YAML], [INI], [RON], [JSON5], [JSONC] files
  - Read from environment
  - Loosely typed — Configuration values may be read in any supported type, as long as there exists a reasonable conversion
  - Access nested fields using a formatted path — Uses a subset of JSONPath; currently supports the child ( `redis.port` ) and subscript operators ( `databases[0].name` )
@@ -22,6 +22,7 @@
 [INI]: https://github.com/zonyitoo/rust-ini
 [RON]: https://github.com/ron-rs/ron
 [JSON5]: https://github.com/callum-oakley/json5-rs
+[JSONC]: https://github.com/dprint/jsonc-parser
 
 Please note that this library can not be used to write changed configuration
 values back to the configuration file(s)!
@@ -36,6 +37,7 @@ values back to the configuration file(s)!
  - `toml` - Adds support for reading TOML files
  - `ron` - Adds support for reading RON files
  - `json5` - Adds support for reading JSON5 files
+ - `jsonc` - Adds support for reading JSONC files
 
 ### Support for custom formats
 

src/file/format/jsonc.rs

@@ -0,0 +1,49 @@
+use std::error::Error;
+
+use crate::format;
+use crate::map::Map;
+use crate::value::{Value, ValueKind};
+use jsonc_parser::JsonValue;
+
+pub(crate) fn parse(
+    uri: Option<&String>,
+    text: &str,
+) -> Result<Map<String, Value>, Box<dyn Error + Send + Sync>> {
+    let value = match jsonc_parser::parse_to_value(text, &Default::default())? {
+        Some(json_value) => from_jsonc_value(uri, json_value),
+        None => Value::new(uri, ValueKind::Nil),
+    };
+    format::extract_root_table(uri, value)
+}
+
+fn from_jsonc_value(uri: Option<&String>, value: JsonValue<'_>) -> Value {
+    let vk = match value {
+        JsonValue::Null => ValueKind::Nil,
+        JsonValue::String(v) => ValueKind::String(v.to_string()),
+        JsonValue::Number(number) => {
+            if let Ok(v) = number.parse::<i64>() {
+                ValueKind::I64(v)
+            } else if let Ok(v) = number.parse::<f64>() {
+                ValueKind::Float(v)
+            } else {
+                unreachable!();
+            }
+        }
+        JsonValue::Boolean(v) => ValueKind::Boolean(v),
+        JsonValue::Object(table) => {
+            let m = table
+                .into_iter()
+                .map(|(k, v)| (k, from_jsonc_value(uri, v)))
+                .collect();
+            ValueKind::Table(m)
+        }
+        JsonValue::Array(array) => {
+            let l = array
+                .into_iter()
+                .map(|v| from_jsonc_value(uri, v))
+                .collect();
+            ValueKind::Array(l)
+        }
+    };
+    Value::new(uri, vk)
+}

src/file/format/mod.rs

@@ -23,6 +23,9 @@ mod ron;
 #[cfg(feature = "json5")]
 mod json5;
 
+#[cfg(feature = "jsonc")]
+mod jsonc;
+
 /// File formats provided by the library.
 ///
 /// Although it is possible to define custom formats using [`Format`] trait it is recommended to use `FileFormat` if possible.
@@ -52,6 +55,10 @@ pub enum FileFormat {
     /// JSON5 (parsed with json5)
     #[cfg(feature = "json5")]
     Json5,
+
+    /// JSONC (parsed with jsonc)
+    #[cfg(feature = "jsonc")]
+    Jsonc,
 }
 
 pub(crate) fn all_extensions() -> &'static HashMap<FileFormat, Vec<&'static str>> {
@@ -79,6 +86,9 @@ pub(crate) fn all_extensions() -> &'static HashMap<FileFormat, Vec<&'static str>
         #[cfg(feature = "json5")]
         formats.insert(FileFormat::Json5, vec!["json5"]);
 
+        #[cfg(feature = "jsonc")]
+        formats.insert(FileFormat::Jsonc, vec!["jsonc"]);
+
         formats
     })
 }
@@ -115,13 +125,17 @@ impl FileFormat {
             #[cfg(feature = "json5")]
             FileFormat::Json5 => json5::parse(uri, text),
 
+            #[cfg(feature = "jsonc")]
+            FileFormat::Jsonc => jsonc::parse(uri, text),
+
             #[cfg(all(
                 not(feature = "toml"),
                 not(feature = "json"),
                 not(feature = "yaml"),
                 not(feature = "ini"),
                 not(feature = "ron"),
                 not(feature = "json5"),
+                not(feature = "jsonc"),
             ))]
             _ => unreachable!("No features are enabled, this library won't work without features"),
         }

tests/testsuite/file_jsonc.enum.jsonc

@@ -0,0 +1,4 @@
+{
+    // foo
+    "bar": "bar is a lowercase param",
+}

tests/testsuite/file_jsonc.error.jsonc

@@ -0,0 +1,4 @@
+{
+  "ok": true,
+  "error"
+}

tests/testsuite/file_jsonc.jsonc

@@ -0,0 +1,23 @@
+{
+  // c
+  /* c */
+  "debug": true,
+  "debug_json": true,
+  "production": false,
+  "arr": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
+  "place": {
+    "name": "Torre di Pisa",
+    "longitude": 43.7224985,
+    "latitude": 10.3970522,
+    "favorite": false,
+    "reviews": 3866,
+    "rating": 4.5,
+    "creator": {
+      "name": "John Smith",
+      "username": "jsmith",
+      "email": "jsmith@localhost"
+    },
+  },
+  "FOO": "FOO should be overridden",
+  "bar": "I am bar",
+}