@@ -98,6 +98,89 @@ pub fn cache_dir() -> std::path::PathBuf {
9898 path
9999}
100100
101+// right overrides left
102+pub fn merge_toml_values(left: toml::Value, right: toml::Value) -> toml::Value {
103+ use toml::Value;
104+
105+ fn get_name(v: &Value) -> Option<&str> {
106+ v.get("name").and_then(Value::as_str)
107+ }
108+
109+ match (left, right) {
110+ (Value::Array(mut left_items), Value::Array(right_items)) => {
111+ left_items.reserve(right_items.len());
112+ for rvalue in right_items {
113+ let lvalue = get_name(&rvalue)
114+ .and_then(|rname| left_items.iter().position(|v| get_name(v) == Some(rname)))
115+ .map(|lpos| left_items.remove(lpos));
116+ let mvalue = match lvalue {
117+ Some(lvalue) => merge_toml_values(lvalue, rvalue),
118+ None => rvalue,
119+ };
120+ left_items.push(mvalue);
121+ }
122+ Value::Array(left_items)
123+ }
124+ (Value::Table(mut left_map), Value::Table(right_map)) => {
125+ for (rname, rvalue) in right_map {
126+ match left_map.remove(&rname) {
127+ Some(lvalue) => {
128+ let merged_value = merge_toml_values(lvalue, rvalue);
129+ left_map.insert(rname, merged_value);
130+ }
131+ None => {
132+ left_map.insert(rname, rvalue);
133+ }
134+ }
135+ }
136+ Value::Table(left_map)
137+ }
138+ // Catch everything else we didn't handle, and use the right value
139+ (_, value) => value,
140+ }
141+}
142+
143+#[cfg(test)]
144+mod merge_toml_tests {
145+ use super::merge_toml_values;
146+
147+ #[test]
148+ fn language_tomls() {
149+ use toml::Value;
150+
151+ const USER: &str = "
152+ [[language]]
153+ name = \"nix\"
154+ test = \"bbb\"
155+ indent = { tab-width = 4, unit = \" \", test = \"aaa\" }
156+ ";
157+
158+ let base: Value = toml::from_slice(include_bytes!("../../languages.toml"))
159+ .expect("Couldn't parse built-in langauges config");
160+ let user: Value = toml::from_str(USER).unwrap();
161+
162+ let merged = merge_toml_values(base, user);
163+ let languages = merged.get("language").unwrap().as_array().unwrap();
164+ let nix = languages
165+ .iter()
166+ .find(|v| v.get("name").unwrap().as_str().unwrap() == "nix")
167+ .unwrap();
168+ let nix_indent = nix.get("indent").unwrap();
169+
170+ // We changed tab-width and unit in indent so check them if they are the new values
171+ assert_eq!(
172+ nix_indent.get("tab-width").unwrap().as_integer().unwrap(),
173+ 4
174+ );
175+ assert_eq!(nix_indent.get("unit").unwrap().as_str().unwrap(), " ");
176+ // We added a new keys, so check them
177+ assert_eq!(nix.get("test").unwrap().as_str().unwrap(), "bbb");
178+ assert_eq!(nix_indent.get("test").unwrap().as_str().unwrap(), "aaa");
179+ // We didn't change comment-token so it should be same
180+ assert_eq!(nix.get("comment-token").unwrap().as_str().unwrap(), "#");
181+ }
182+}
183+
101184pub use etcetera::home_dir;
102185
103186use etcetera::base_strategy::{choose_base_strategy, BaseStrategy};