feat: Add deserialize_map support (#11)

Signed-off-by: Xuanwo <github@xuanwo.io>

src/de.rs

@@ -253,13 +253,9 @@ impl<'de> de::Deserializer<'de> for Deserializer {
     where
         V: Visitor<'de>,
     {
-        debug!(
-            "deserialize map: {:?}, {:?}",
-            &self.0.value(),
-            &self.0.children()
-        );
+        debug!("deserialize map: {:#?}", &self.0);
 
-        let keys = self.0.children().keys().map(|v| v.to_string()).collect();
+        let keys = self.0.flatten("");
         vis.visit_map(MapAccessor::new(keys, self.0))
     }
 
@@ -278,6 +274,7 @@ impl<'de> de::Deserializer<'de> for Deserializer {
         );
 
         let keys = fields.iter().map(|v| v.to_string()).collect();
+        debug!("flatten keys: {:?}", keys);
         vis.visit_map(MapAccessor::new(keys, self.0))
     }
 
@@ -601,7 +598,6 @@ mod tests {
     }
 
     #[test]
-    #[ignore]
     fn test_from_env_as_map() {
         let _ = env_logger::try_init();
 

src/value.rs

@@ -46,9 +46,29 @@ impl Node {
         self.0
     }
 
-    /// Get children from node.
-    pub fn children(&self) -> &BTreeMap<String, Node> {
-        &self.1
+    pub fn flatten(&self, prefix: &str) -> Vec<String> {
+        let mut m = Vec::new();
+
+        for (key, value) in self.1.iter() {
+            let prefix_key = if prefix.is_empty() {
+                key.to_string()
+            } else {
+                format!("{prefix}_{key}")
+            };
+
+            if !value.0.is_empty() {
+                m.push(prefix_key.clone())
+            }
+            if !value.1.is_empty() {
+                m.push(prefix_key.clone());
+                m.extend(value.flatten(&prefix_key))
+            }
+        }
+
+        m.sort();
+        m.dedup();
+
+        m
     }
 
     /// Get node value full key name
@@ -171,4 +191,19 @@ mod tests {
             )
         )
     }
+
+    #[test]
+    fn test_flatten() {
+        let mut root = Node::new("");
+
+        root.push("a", "Hello, World!");
+        root.push("a_b_c_d", "Hello, World!");
+        root.push("a_b_c_e", "Hello, Mars!");
+        root.push("a_b_f", "Hello, Moon!");
+
+        assert_eq!(
+            root.flatten(""),
+            vec!["a", "a_b", "a_b_c", "a_b_c_d", "a_b_c_e", "a_b_f"]
+        );
+    }
 }