Support format json5

4 files changed, 109 insertions, 3 deletions

diff --git a/src/error.rs b/src/error.rs
index 28142b5..9778649 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -94,6 +94,18 @@ impl ConfigError {
         }
     }
 
+    // Have a proper error fire if the root of a file is ever not a Table
+    // TODO: for now only json5 checked, need to finish others
+    #[doc(hidden)]
+    pub fn invalid_root(origin: Option<&String>, unexpected: Unexpected) -> Box<Self> {
+        Box::new(ConfigError::Type {
+            origin: origin.map(|s| s.to_owned()),
+            unexpected,
+            expected: "a map",
+            key: None,
+        })
+    }
+
     // FIXME: pub(crate)
     #[doc(hidden)]
     pub fn extend_with_key(self, key: &str) -> Self {
diff --git a/src/file/format/json5.rs b/src/file/format/json5.rs
new file mode 100644
index 0000000..320e574
--- /dev/null
+++ b/src/file/format/json5.rs
@@ -0,0 +1,78 @@
+use serde_derive::Deserialize;
+
+use std::collections::HashMap;
+use std::error::Error;
+
+use crate::error::{ConfigError, Unexpected};
+use crate::value::{Value, ValueKind};
+
+#[derive(Deserialize, Debug)]
+#[serde(untagged)]
+pub enum Val {
+    Null,
+    Boolean(bool),
+    Integer(i64),
+    Float(f64),
+    String(String),
+    Array(Vec<Val>),
+    Object(HashMap<String, Val>),
+}
+
+pub fn parse(
+    uri: Option<&String>,
+    text: &str,
+) -> Result<HashMap<String, Value>, Box<dyn Error + Send + Sync>> {
+    let root = json5_rs::from_str::<Val>(&text)?;
+    if let Some(err) = match root {
+        Val::String(ref value) => Some(Unexpected::Str(value.clone())),
+        Val::Integer(value) => Some(Unexpected::Integer(value)),
+        Val::Float(value) => Some(Unexpected::Float(value)),
+        Val::Boolean(value) => Some(Unexpected::Bool(value)),
+        Val::Object(_) => None,
+        Val::Array(_) => Some(Unexpected::Seq),
+        Val::Null => Some(Unexpected::Unit),
+    } {
+        return Err(ConfigError::invalid_root(uri, err));
+    }
+
+    let value = from_json5_value(uri, root);
+    match value.kind {
+        ValueKind::Table(map) => Ok(map),
+
+        _ => Ok(HashMap::new()),
+    }
+}
+
+fn from_json5_value(uri: Option<&String>, value: Val) -> Value {
+    match value {
+        Val::String(v) => Value::new(uri, ValueKind::String(v)),
+
+        Val::Integer(v) => Value::new(uri, ValueKind::Integer(v)),
+
+        Val::Float(v) => Value::new(uri, ValueKind::Float(v)),
+
+        Val::Boolean(v) => Value::new(uri, ValueKind::Boolean(v)),
+
+        Val::Object(table) => {
+            let mut m = HashMap::new();
+
+            for (key, value) in table {
+                m.insert(key, from_json5_value(uri, value));
+            }
+
+            Value::new(uri, ValueKind::Table(m))
+        }
+
+        Val::Array(array) => {
+            let mut l = Vec::new();
+
+            for value in array {
+                l.push(from_json5_value(uri, value));
+            }
+
+            Value::new(uri, ValueKind::Array(l))
+        }
+
+        Val::Null => Value::new(uri, ValueKind::Nil),
+    }
+}
diff --git a/src/file/format/mod.rs b/src/file/format/mod.rs
index bbd62a2..53bacf6 100644
--- a/src/file/format/mod.rs
+++ b/src/file/format/mod.rs
@@ -25,6 +25,9 @@ mod ini;
 #[cfg(feature = "ron")]
 mod ron;
 
+#[cfg(feature = "json5")]
+mod json5;
+
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub enum FileFormat {
     /// TOML (parsed with toml)
@@ -42,6 +45,7 @@ pub enum FileFormat {
     /// HJSON (parsed with serde_hjson)
     #[cfg(feature = "hjson")]
     Hjson,
+
     /// INI (parsed with rust_ini)
     #[cfg(feature = "ini")]
     Ini,
@@ -49,6 +53,10 @@ pub enum FileFormat {
     /// RON (parsed with ron)
     #[cfg(feature = "ron")]
     Ron,
+
+    /// JSON5 (parsed with json5)
+    #[cfg(feature = "json5")]
+    Json5,
 }
 
 lazy_static! {
@@ -75,6 +83,9 @@ lazy_static! {
         #[cfg(feature = "ron")]
         formats.insert(FileFormat::Ron, vec!["ron"]);
 
+        #[cfg(feature = "json5")]
+        formats.insert(FileFormat::Json5, vec!["json5"]);
+
         formats
     };
 }
@@ -115,6 +126,9 @@ impl FileFormat {
 
             #[cfg(feature = "ron")]
             FileFormat::Ron => ron::parse(uri, text),
+
+            #[cfg(feature = "json5")]
+            FileFormat::Json5 => json5::parse(uri, text),
         }
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index ae02c36..986f36a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,7 +6,7 @@
 //!  - Environment variables
 //!  - Another Config instance
 //!  - Remote configuration: etcd, Consul
-//!  - Files: TOML, JSON, YAML, HJSON, INI, RON
+//!  - Files: TOML, JSON, YAML, HJSON, INI, RON, JSON5
 //!  - Manual, programmatic override (via a `.set` method on the Config instance)
 //!
 //! Additionally, Config supports:
@@ -24,8 +24,7 @@
 #[macro_use]
 extern crate serde;
 
-#[cfg(test)]
-#[macro_use]
+#[cfg(any(test, feature = "json5"))]
 extern crate serde_derive;
 
 extern crate nom;
@@ -51,6 +50,9 @@ extern crate ini;
 #[cfg(feature = "ron")]
 extern crate ron;
 
+#[cfg(feature = "json5")]
+extern crate json5_rs;
+
 mod builder;
 mod config;
 mod de;