fix: Support Yaml values

- Required switching to `serde_yaml`.
- Like with `yaml-rust`, requires special handling for table keys.

Signed-off-by: Brennan Kinney <5098581+polarathene@users.noreply.github.com>

Author: polarathene

Cargo.toml

@@ -17,7 +17,7 @@ maintenance = { status = "actively-developed" }
 [features]
 default = ["toml", "json", "yaml", "ini", "ron", "json5", "convert-case", "async"]
 json = ["serde_json"]
-yaml = ["yaml-rust"]
+yaml = ["serde_yaml"]
 ini = ["rust-ini"]
 json5 = ["json5_rs", "serde/derive"]
 convert-case = ["convert_case"]
@@ -33,7 +33,7 @@ nom = "7"
 async-trait = { version = "0.1.50", optional = true }
 toml = { version = "0.8", optional = true }
 serde_json = { version = "1.0.2", optional = true }
-yaml-rust = { version = "0.4", optional = true }
+serde_yaml  = { version = "0.9", optional = true }
 rust-ini = { version = "0.19", optional = true }
 ron = { version = "0.8", optional = true }
 json5_rs = { version = "0.4", optional = true, package = "json5" }

README.md

@@ -18,7 +18,7 @@
 
 [JSON]: https://github.com/serde-rs/json
 [TOML]: https://github.com/toml-lang/toml
-[YAML]: https://github.com/chyh1990/yaml-rust
+[YAML]: https://github.com/dtolnay/serde-yaml
 [INI]: https://github.com/zonyitoo/rust-ini
 [RON]: https://github.com/ron-rs/ron
 [JSON5]: https://github.com/callum-oakley/json5-rs

src/file/format/mod.rs

@@ -40,7 +40,7 @@ pub enum FileFormat {
     #[cfg(feature = "json")]
     Json,
 
-    /// YAML (parsed with yaml_rust)
+    /// YAML (parsed with serde_yaml)
     #[cfg(feature = "yaml")]
     Yaml,
 

src/file/format/yaml.rs

@@ -1,105 +1,14 @@
 use std::error::Error;
-use std::fmt;
-use std::mem;
-
-use yaml_rust as yaml;
 
 use crate::format;
 use crate::map::Map;
-use crate::value::{Value, ValueKind};
+use crate::value::Value;
 
 pub fn parse(
     uri: Option<&String>,
     text: &str,
 ) -> Result<Map<String, Value>, Box<dyn Error + Send + Sync>> {
-    // Parse a YAML object from file
-    let mut docs = yaml::YamlLoader::load_from_str(text)?;
-    let root = match docs.len() {
-        0 => yaml::Yaml::Hash(yaml::yaml::Hash::new()),
-        1 => mem::replace(&mut docs[0], yaml::Yaml::Null),
-        n => {
-            return Err(Box::new(MultipleDocumentsError(n)));
-        }
-    };
-
-    let value = from_yaml_value(uri, &root)?;
+    // Parse a YAML input from the provided text
+    let value = format::from_parsed_value(uri, serde_yaml::from_str(text)?);
     format::extract_root_table(uri, value)
 }
-
-fn from_yaml_value(
-    uri: Option<&String>,
-    value: &yaml::Yaml,
-) -> Result<Value, Box<dyn Error + Send + Sync>> {
-    match *value {
-        yaml::Yaml::String(ref value) => Ok(Value::new(uri, ValueKind::String(value.clone()))),
-        yaml::Yaml::Real(ref value) => {
-            // TODO: Figure out in what cases this can panic?
-            value
-                .parse::<f64>()
-                .map_err(|_| {
-                    Box::new(FloatParsingError(value.to_string())) as Box<(dyn Error + Send + Sync)>
-                })
-                .map(ValueKind::Float)
-                .map(|f| Value::new(uri, f))
-        }
-        yaml::Yaml::Integer(value) => Ok(Value::new(uri, ValueKind::I64(value))),
-        yaml::Yaml::Boolean(value) => Ok(Value::new(uri, ValueKind::Boolean(value))),
-        yaml::Yaml::Hash(ref table) => {
-            let mut m = Map::new();
-            for (key, value) in table {
-                match key {
-                    yaml::Yaml::String(k) => m.insert(k.to_owned(), from_yaml_value(uri, value)?),
-                    yaml::Yaml::Integer(k) => m.insert(k.to_string(), from_yaml_value(uri, value)?),
-                    _ => unreachable!(),
-                };
-            }
-            Ok(Value::new(uri, ValueKind::Table(m)))
-        }
-        yaml::Yaml::Array(ref array) => {
-            let mut l = Vec::new();
-
-            for value in array {
-                l.push(from_yaml_value(uri, value)?);
-            }
-
-            Ok(Value::new(uri, ValueKind::Array(l)))
-        }
-
-        // 1. Yaml NULL
-        // 2. BadValue – It shouldn't be possible to hit BadValue as this only happens when
-        //               using the index trait badly or on a type error but we send back nil.
-        // 3. Alias – No idea what to do with this and there is a note in the lib that its
-        //            not fully supported yet anyway
-        _ => Ok(Value::new(uri, ValueKind::Nil)),
-    }
-}
-
-#[derive(Debug, Copy, Clone)]
-struct MultipleDocumentsError(usize);
-
-impl fmt::Display for MultipleDocumentsError {
-    fn fmt(&self, format: &mut fmt::Formatter) -> fmt::Result {
-        write!(format, "Got {} YAML documents, expected 1", self.0)
-    }
-}
-
-impl Error for MultipleDocumentsError {
-    fn description(&self) -> &str {
-        "More than one YAML document provided"
-    }
-}
-
-#[derive(Debug, Clone)]
-struct FloatParsingError(String);
-
-impl fmt::Display for FloatParsingError {
-    fn fmt(&self, format: &mut fmt::Formatter) -> fmt::Result {
-        write!(format, "Parsing {} as floating point number failed", self.0)
-    }
-}
-
-impl Error for FloatParsingError {
-    fn description(&self) -> &str {
-        "Floating point number parsing failed"
-    }
-}

src/format.rs

@@ -62,6 +62,7 @@ pub enum ParsedValue {
     Float(f64),
     #[serde(deserialize_with = "deserialize_parsed_string")]
     String(String),
+    #[serde(deserialize_with = "deserialize_parsed_map")]
     Table(Map<String, Self>),
     Array(Vec<Self>),
     Option(Option<Box<Self>>),
@@ -139,3 +140,42 @@ where
         },
     }
 }
+
+fn deserialize_parsed_map<'de, D>(deserializer: D) -> Result<Map<String, ParsedValue>, D::Error>
+where
+    D: serde::de::Deserializer<'de>,
+{
+    #[derive(serde::Deserialize)]
+    #[serde(untagged)]
+    enum ParsedMap {
+        // Anything that can deserialize into a Map successfully:
+        Table(Map<String, ParsedValue>),
+        // Config specific support for types that need string conversion:
+        #[cfg(feature = "yaml")]
+        YamlMap(serde_yaml::Mapping),
+    }
+
+    match ParsedMap::deserialize(deserializer)? {
+        ParsedMap::Table(v) => Ok(v),
+        #[cfg(feature = "yaml")]
+        ParsedMap::YamlMap(table) => {
+            table
+                .into_iter()
+                .map(|(key, value)| {
+                    let key = match key {
+                        serde_yaml::Value::Number(k) => Some(k.to_string()),
+                        serde_yaml::Value::String(k) => Some(k.to_string()),
+                        _ => None,
+                    };
+                    let value = serde_yaml::from_value::<ParsedValue>(value).ok();
+
+                    // Option to Result:
+                    match (key ,value) {
+                        (Some(k), Some(v)) => Ok((k,v)),
+                        _ => Err(serde::de::Error::custom("should not be serialized to Map")),
+                    }
+                })
+                .collect()
+        }
+    }
+}

tests/file_yaml.rs

@@ -81,12 +81,13 @@ fn test_error_parse() {
 
     let path_with_extension: PathBuf = ["tests", "Settings-invalid.yaml"].iter().collect();
 
+    // Should fail to parse block mapping as no `:` exists to identify a key
     assert!(res.is_err());
     assert_eq!(
         res.unwrap_err().to_string(),
         format!(
-            "while parsing a block mapping, did not find expected key at \
-         line 2 column 1 in {}",
+            "could not find expected ':' at line 3 column 1, \
+            while scanning a simple key at line 2 column 1 in {}",
             path_with_extension.display()
         )
     );