Merge pull request #5 from ChrisRega/feature/0.6.0-new-diffs-api

Improve API for library usage

Author: ChrisRega

Cargo.toml

@@ -1,10 +1,10 @@
 [package]
 name = "json_diff_ng"
-version = "0.5.0"
+version = "0.6.0-RC1"
 authors = ["ksceriath", "ChrisRega"]
 edition = "2021"
 license = "Unlicense"
-description = "A small diff tool utility for comparing jsons. Forked from ksceriath and improved for usage as a library and with good support for array diffs."
+description = "A small diff tool utility for comparing jsons. Forked from ksceriath and improved for usage as a library and with proper support for array diffs."
 readme = "README.md"
 homepage = "https://github.com/ChrisRega/json-diff"
 repository = "https://github.com/ChrisRega/json-diff"

src/ds/key_node.rs

@@ -1,65 +1,54 @@
-use crate::enums::ValueType;
-use serde_json::Value;
 use std::collections::HashMap;
 
+use serde_json::Value;
+
+use crate::enums::{DiffEntry, PathElement};
+
 #[derive(Debug, PartialEq)]
 pub enum KeyNode {
     Nil,
     Value(Value, Value),
     Node(HashMap<String, KeyNode>),
-}
-
-fn truncate(s: &str, max_chars: usize) -> String {
-    match s.char_indices().nth(max_chars) {
-        None => String::from(s),
-        Some((idx, _)) => {
-            let shorter = &s[..idx];
-            let snip = "//SNIP//";
-            let new_s = format!("{}{}", shorter, snip);
-            new_s
-        }
-    }
+    Array(Vec<(usize, KeyNode)>),
 }
 
 impl KeyNode {
-    pub fn absolute_keys_to_vec(&self, max_display_length: Option<usize>) -> Vec<ValueType> {
-        let mut vec = Vec::new();
-        self.absolute_keys(&mut vec, None, max_display_length);
-        vec
+    pub fn get_diffs(&self) -> Vec<DiffEntry> {
+        let mut buf = Vec::new();
+        self.follow_path(&mut buf, &[]);
+        buf
     }
 
-    pub fn absolute_keys(
-        &self,
-        keys: &mut Vec<ValueType>,
-        key_from_root: Option<String>,
-        max_display_length: Option<usize>,
-    ) {
-        let max_display_length = max_display_length.unwrap_or(4000);
-        let val_key = |key: Option<String>| {
-            key.map(|mut s| {
-                s.push_str("->");
-                s
-            })
-            .unwrap_or_default()
-        };
+    pub fn follow_path(&self, diffs: &mut Vec<DiffEntry>, offset: &[PathElement]) {
         match self {
             KeyNode::Nil => {
-                if let Some(key) = key_from_root {
-                    keys.push(ValueType::new_key(key))
+                let is_map_child = offset
+                    .last()
+                    .map(|o| matches!(o, PathElement::Object(_)))
+                    .unwrap_or_default();
+                if is_map_child {
+                    diffs.push(DiffEntry {
+                        path: offset.to_vec(),
+                        values: None,
+                    });
+                }
+            }
+            KeyNode::Value(l, r) => diffs.push(DiffEntry {
+                path: offset.to_vec(),
+                values: Some((l.to_string(), r.to_string())),
+            }),
+            KeyNode::Node(o) => {
+                for (k, v) in o {
+                    let mut new_offset = offset.to_vec();
+                    new_offset.push(PathElement::Object(k.clone()));
+                    v.follow_path(diffs, &new_offset);
                 }
             }
-            KeyNode::Value(a, b) => keys.push(ValueType::new_value(
-                val_key(key_from_root),
-                truncate(a.to_string().as_str(), max_display_length),
-                truncate(b.to_string().as_str(), max_display_length),
-            )),
-            KeyNode::Node(map) => {
-                for (key, value) in map {
-                    value.absolute_keys(
-                        keys,
-                        Some(format!("{}{}", val_key(key_from_root.clone()), key)),
-                        Some(max_display_length),
-                    )
+            KeyNode::Array(v) => {
+                for (l, k) in v {
+                    let mut new_offset = offset.to_vec();
+                    new_offset.push(PathElement::ArrayEntry(*l));
+                    k.follow_path(diffs, &new_offset);
                 }
             }
         }

src/ds/mismatch.rs

@@ -1,5 +1,5 @@
 use crate::ds::key_node::KeyNode;
-use crate::enums::{DiffType, ValueType};
+use crate::enums::{DiffEntry, DiffType};
 
 #[derive(Debug, PartialEq)]
 pub struct Mismatch {
@@ -31,24 +31,20 @@ impl Mismatch {
             && self.right_only_keys == KeyNode::Nil
     }
 
-    pub fn all_diffs(&self) -> Vec<(DiffType, ValueType)> {
-        self.all_diffs_trunc(None)
-    }
-
-    pub fn all_diffs_trunc(&self, truncation_length: Option<usize>) -> Vec<(DiffType, ValueType)> {
+    pub fn all_diffs(&self) -> Vec<(DiffType, DiffEntry)> {
         let both = self
             .keys_in_both
-            .absolute_keys_to_vec(truncation_length)
+            .get_diffs()
             .into_iter()
             .map(|k| (DiffType::Mismatch, k));
         let left = self
             .left_only_keys
-            .absolute_keys_to_vec(truncation_length)
+            .get_diffs()
             .into_iter()
             .map(|k| (DiffType::LeftExtra, k));
         let right = self
             .right_only_keys
-            .absolute_keys_to_vec(truncation_length)
+            .get_diffs()
             .into_iter()
             .map(|k| (DiffType::RightExtra, k));
 
@@ -59,6 +55,7 @@ impl Mismatch {
 #[cfg(test)]
 mod test {
     use super::*;
+
     #[test]
     fn empty_diffs() {
         let empty = Mismatch::empty();

src/enums.rs

@@ -1,4 +1,5 @@
 use std::fmt::{Display, Formatter};
+
 use thiserror::Error;
 use vg_errortools::FatIOError;
 
@@ -30,45 +31,42 @@ impl Display for DiffType {
     }
 }
 
-pub enum ValueType {
-    Key(String),
-    Value {
-        key: String,
-        value_left: String,
-        value_right: String,
-    },
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum PathElement {
+    Object(String),
+    ArrayEntry(usize),
 }
 
-impl ValueType {
-    pub fn new_value(key: String, value_left: String, value_right: String) -> Self {
-        Self::Value {
-            value_right,
-            value_left,
-            key,
-        }
-    }
-    pub fn new_key(key: String) -> Self {
-        Self::Key(key)
-    }
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct DiffEntry {
+    pub path: Vec<PathElement>,
+    pub values: Option<(String, String)>,
+}
 
-    pub fn get_key(&self) -> &str {
-        match self {
-            ValueType::Value { key, .. } => key.as_str(),
-            ValueType::Key(key) => key.as_str(),
+impl Display for DiffEntry {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        for element in &self.path {
+            write!(f, ".{element}")?;
         }
+        if let Some((l, r)) = &self.values {
+            if l != r {
+                write!(f, ".({l} != {r})")?;
+            } else {
+                write!(f, ".({l})")?;
+            }
+        }
+        Ok(())
     }
 }
 
-impl Display for ValueType {
+impl Display for PathElement {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self {
-            ValueType::Key(key) => write!(f, "{key}"),
-            ValueType::Value {
-                value_left,
-                key,
-                value_right,
-            } => {
-                write!(f, "{key}{{{value_left}!={value_right}}}")
+            PathElement::Object(o) => {
+                write!(f, "{o}")
+            }
+            PathElement::ArrayEntry(l) => {
+                write!(f, "[{l}]")
             }
         }
     }