Allow errors to be returned from the replace with closure

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "jsonpath_lib"
-version = "0.2.6"
+version = "0.2.7"
 authors = ["Changseok Han <freestrings@gmail.com>"]
 
 description = "It is JsonPath engine written in Rust. it provide a similar API interface in Webassembly and Javascript too. - Webassembly Demo: https://freestrings.github.io/jsonpath"

src/lib.rs

@@ -450,7 +450,7 @@ pub fn delete(value: Value, path: &str) -> Result<Value, JsonPathError> {
 ///         0
 ///     };
 ///
-///     Some(json!(age))
+///     Ok(Some(json!(age)))
 /// }).unwrap();
 ///
 /// assert_eq!(ret, json!({
@@ -467,7 +467,7 @@ pub fn delete(value: Value, path: &str) -> Result<Value, JsonPathError> {
 /// ```
 pub fn replace_with<F>(value: Value, path: &str, fun: &mut F) -> Result<Value, JsonPathError>
 where
-    F: FnMut(Value) -> Option<Value>,
+    F: FnMut(Value) -> Result<Option<Value>, JsonPathError>,
 {
     let mut selector = SelectorMut::default();
     let value = selector.str_path(path)?.value(value).replace_with(fun)?;

src/select/mod.rs

@@ -42,6 +42,7 @@ pub enum JsonPathError {
     EmptyValue,
     Path(String),
     Serde(String),
+    Replacement(String)
 }
 
 impl fmt::Debug for JsonPathError {
@@ -57,6 +58,7 @@ impl fmt::Display for JsonPathError {
             JsonPathError::EmptyValue => f.write_str("json value not set"),
             JsonPathError::Path(msg) => f.write_str(&format!("path error: \n{}\n", msg)),
             JsonPathError::Serde(msg) => f.write_str(&format!("serde error: \n{}\n", msg)),
+            JsonPathError::Replacement(msg) => f.write_str(&format!("error occurred during jsonpath replacement: \n{}\n", msg))
         }
     }
 }
@@ -780,11 +782,11 @@ pub struct SelectorMut {
     value: Option<Value>,
 }
 
-fn replace_value<F: FnMut(Value) -> Option<Value>>(
+fn replace_value<F: FnMut(Value) -> Result<Option<Value>, JsonPathError>>(
     mut tokens: Vec<String>,
     value: &mut Value,
     fun: &mut F,
-) {
+) -> Result<(), JsonPathError> {
     let mut target = value;
 
     let last_index = tokens.len().saturating_sub(1);
@@ -796,26 +798,26 @@ fn replace_value<F: FnMut(Value) -> Option<Value>>(
                 if is_last {
                     if let Entry::Occupied(mut e) = map.entry(token) {
                         let v = e.insert(Value::Null);
-                        if let Some(res) = fun(v) {
+                        if let Some(res) = fun(v)? {
                             e.insert(res);
                         } else {
                             e.remove();
                         }
                     }
-                    return;
+                    return Ok(());
                 }
                 map.get_mut(&token)
             }
             Value::Array(ref mut vec) => {
                 if let Ok(x) = token.parse::<usize>() {
                     if is_last {
                         let v = std::mem::replace(&mut vec[x], Value::Null);
-                        if let Some(res) = fun(v) {
+                        if let Some(res) = fun(v)? {
                             vec[x] = res;
                         } else {
                             vec.remove(x);
                         }
-                        return;
+                        return Ok(());
                     }
                     vec.get_mut(x)
                 } else {
@@ -831,6 +833,7 @@ fn replace_value<F: FnMut(Value) -> Option<Value>>(
             break;
         }
     }
+    Ok(())
 }
 
 impl SelectorMut {
@@ -920,11 +923,11 @@ impl SelectorMut {
     }
 
     pub fn delete(&mut self) -> Result<&mut Self, JsonPathError> {
-        self.replace_with(&mut |_| Some(Value::Null))
+        self.replace_with(&mut |_| Ok(Some(Value::Null)))
     }
 
     pub fn remove(&mut self) -> Result<&mut Self, JsonPathError> {
-        self.replace_with(&mut |_| None)
+        self.replace_with(&mut |_| Ok(None))
     }
 
     fn select(&self) -> Result<Vec<&Value>, JsonPathError> {
@@ -942,7 +945,7 @@ impl SelectorMut {
         }
     }
 
-    pub fn replace_with<F: FnMut(Value) -> Option<Value>>(
+    pub fn replace_with<F: FnMut(Value) -> Result<Option<Value>, JsonPathError>>(
         &mut self,
         fun: &mut F,
     ) -> Result<&mut Self, JsonPathError> {
@@ -953,7 +956,7 @@ impl SelectorMut {
 
         if let Some(ref mut value) = &mut self.value {
             for tokens in paths {
-                replace_value(tokens, value, fun);
+                replace_value(tokens, value, fun)?;
             }
         }
 

tests/readme.rs

@@ -224,7 +224,7 @@ fn readme_selector_mut() {
                 0
             };
 
-            Some(json!(age))
+            Ok(Some(json!(age)))
         })
         .unwrap()
         .take()
@@ -522,7 +522,7 @@ fn readme_replace_with() {
             0
         };
 
-        Some(json!(age))
+        Ok(Some(json!(age)))
     })
     .unwrap();
 

tests/selector.rs

@@ -3,7 +3,7 @@ extern crate jsonpath_lib as jsonpath;
 extern crate serde_json;
 
 use common::{read_json, setup};
-use jsonpath::{Parser, Selector, SelectorMut};
+use jsonpath::{Parser, Selector, SelectorMut, JsonPathError};
 use serde_json::Value;
 
 mod common;
@@ -23,7 +23,7 @@ fn selector_mut() {
             if let Value::Number(n) = v {
                 nums.push(n.as_f64().unwrap());
             }
-            Some(Value::String("a".to_string()))
+            Ok(Some(Value::String("a".to_string())))
         })
         .unwrap()
         .take()
@@ -54,6 +54,25 @@ fn selector_mut() {
     );
 }
 
+#[test]
+fn selector_mut_err() {
+    setup();
+
+    let mut selector_mut = SelectorMut::default();
+    let result = selector_mut
+        .str_path(r#"$.store..price"#)
+        .unwrap()
+        .value(read_json("./benchmark/example.json"))
+        .replace_with(&mut |_| {
+            Err(JsonPathError::EmptyValue)
+        });
+
+    assert_eq!(
+        result.is_err(),
+        true
+    );
+}
+
 #[test]
 fn selector_node_ref() {
     let node = Parser::compile("$.*").unwrap();