Feature/0.6.0 better error handling

.github/workflows/coverage.yml

@@ -0,0 +1,44 @@
+name: coverage instrument based
+
+on: [ push, pull_request ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install latest nightly
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly
+          override: true
+          components: rustfmt, clippy, llvm-tools-preview
+
+      - name: Install lcov
+        run: sudo apt-get install lcov
+
+      - name: install grcov
+        run: cargo install grcov
+
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Run grcov
+        env:
+          PROJECT_NAME: "json-diff"
+          RUSTDOCFLAGS: "-Cinstrument-coverage -Ccodegen-units=1 -Copt-level=0 -Clink-dead-code -Coverflow-checks=off -Zpanic_abort_tests -Cpanic=abort"
+          RUSTFLAGS: "-Cinstrument-coverage -Ccodegen-units=1 -Copt-level=0 -Clink-dead-code -Coverflow-checks=off -Zpanic_abort_tests -Cpanic=abort"
+          CARGO_INCREMENTAL: 0
+        run: |
+          cargo +nightly build --verbose
+          cargo +nightly test --verbose
+          grcov . -s . --binary-path ./target/debug/ -t lcov --llvm --branch --ignore-not-existing --ignore="/*" --ignore="target/*" --ignore="tests/*"  -o lcov.info
+
+      - name: Push grcov results to Coveralls via GitHub Action
+        uses: coverallsapp/github-action@v1.0.1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          path-to-lcov: "lcov.info"

README.md

@@ -3,7 +3,8 @@
 [![Crates.io](https://img.shields.io/crates/d/json_diff_ng?style=flat)](https://crates.io/crates/json_diff_ng)
 [![Documentation](https://docs.rs/json_diff_ng/badge.svg)](https://docs.rs/json_diff_ng)
 ![CI](https://github.com/ChrisRega/json-diff/actions/workflows/rust.yml/badge.svg?branch=master "CI")
-[![License](https://img.shields.io/badge/license-MIT-blue?style=flat)](LICENSE)
+[![Coverage Status](https://coveralls.io/repos/github/ChrisRega/json-diff/badge.svg?branch=master)](https://coveralls.io/github/ChrisRega/json-diff?branch=master)
+[![License](https://img.shields.io/github/license/ChrisRega/json-diff)](LICENSE)
 
 ## Contributors:
 
@@ -12,31 +13,34 @@
 </a>
 
 ## Library
+
 json_diff_ng can be used to get diffs of json-serializable structures in rust.
 
 ### Usage example
+
 ```rust
 use json_diff::compare_strs;
 let data1 = r#"["a",{"c": ["d","f"] },"b"]"#;
 let data2 = r#"["b",{"c": ["e","d"] },"a"]"#;
-let diffs = compare_strs(data1, data2, true, &[]).unwrap();
+let diffs = compare_strs(data1, data2, true, & []).unwrap();
 assert!(!diffs.is_empty());
 let diffs = diffs.unequal_values.get_diffs();
 assert_eq!(diffs.len(), 1);
 assert_eq!(
-  diffs.first().unwrap().to_string(),
-  r#".[0].c.[1].("f" != "e")"#
+    diffs.first().unwrap().to_string(),
+    r#".[0].c.[1].("f" != "e")"#
 );
 ```
 
 See [docs.rs](https://docs.rs/json_diff_ng) for more details.
 
-
 ## CLI
-json-diff is a command line utility to compare two jsons.  
+
+json-diff is a command line utility to compare two jsons.
 
 Input can be fed as inline strings or through files.  
-For readability, output is neatly differentiated into three categories: keys with different values, and keys not present in either of the objects.  
+For readability, output is neatly differentiated into three categories: keys with different values, and keys not present
+in either of the objects.  
 Only missing or unequal keys are printed in output to reduce the verbosity.
 
 Usage Example:
@@ -50,5 +54,6 @@ file   :   read input from json files
 direct   :   read input from command line
 
 ### Installation
+
 `$ cargo install json_diff_ng`
 

src/enums.rs

@@ -1,5 +1,7 @@
+use std::collections::HashMap;
 use std::fmt::{Display, Formatter};
 
+use serde_json::Value;
 use thiserror::Error;
 use vg_errortools::FatIOError;
 
@@ -19,10 +21,6 @@ impl From<String> for Error {
     }
 }
 
-use std::collections::HashMap;
-
-use serde_json::Value;
-
 #[derive(Debug, PartialEq)]
 pub enum DiffTreeNode {
     Null,
@@ -123,13 +121,23 @@ impl<'a> PathElement<'a> {
     }
 }
 
-/// A view on a single end-node of the [`DiffKeyNode`] tree.
+/// A view on a single end-node of the [`DiffTreeNode`] tree.
 #[derive(Clone, Debug, Default, PartialEq, Eq)]
 pub struct DiffEntry<'a> {
     pub path: Vec<PathElement<'a>>,
     pub values: Option<(&'a serde_json::Value, &'a serde_json::Value)>,
 }
 
+impl<'a> DiffEntry<'a> {
+    pub fn resolve<'b>(&'a self, value: &'b serde_json::Value) -> Option<&'b serde_json::Value> {
+        let mut return_value = value;
+        for a in &self.path {
+            return_value = a.resolve(return_value)?;
+        }
+        Some(return_value)
+    }
+}
+
 impl Display for DiffEntry<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         for element in &self.path {
@@ -158,3 +166,29 @@ impl Display for PathElement<'_> {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use serde_json::json;
+
+    use crate::compare_serde_values;
+    use crate::sort::sort_value;
+
+    #[test]
+    fn test_resolve() {
+        let data1 = json! {["a",{"c": ["d","f"] },"b"]};
+        let data2 = json! {["b",{"c": ["e","d"] },"a"]};
+        let diffs = compare_serde_values(&data1, &data2, true, &[]).unwrap();
+        assert!(!diffs.is_empty());
+        let data1_sorted = sort_value(&data1, &[]);
+        let data2_sorted = sort_value(&data2, &[]);
+
+        let all_diffs = diffs.all_diffs();
+        assert_eq!(all_diffs.len(), 1);
+        let (_type, diff) = all_diffs.first().unwrap();
+        let val = diff.resolve(&data1_sorted);
+        assert_eq!(val.unwrap().as_str().unwrap(), "f");
+        let val = diff.resolve(&data2_sorted);
+        assert_eq!(val.unwrap().as_str().unwrap(), "e");
+    }
+}

src/lib.rs

@@ -23,17 +23,54 @@
 //! a flat list of [`DiffEntry`] which is more easily usable. The path in the json is collapsed into a vector of [`PathElement`] which can be used to follow the diff.
 //! Similarly, all diffs after an operation can be collected using [`Mismatch::all_diffs`].
 //!
+//! ### Just print everything
+//!
+//! ```rust
+//! use serde_json::json;
+//! use json_diff_ng::compare_serde_values;
+//! use json_diff_ng::sort::sort_value;
+//! let data1 = json! {["a",{"c": ["d","f"] },"b"]};
+//! let data2 = json! {["b",{"c": ["e","d"] },"a"]};
+//! let diffs = compare_serde_values(&data1, &data2, true, &[]).unwrap();
+//! for (d_type, d_path) in diffs.all_diffs() {
+//!   let _message = format!("{d_type}: {d_path}");
+//! }
+//! ```
+//!
+//! ### Traversing the diff result JSONs
+//! ```rust
+//! use serde_json::json;
+//! use json_diff_ng::compare_serde_values;
+//! use json_diff_ng::sort::sort_value;
+//! let data1 = json! {["a",{"c": ["d","f"] },"b"]};
+//! let data2 = json! {["b",{"c": ["e","d"] },"a"]};
+//! let diffs = compare_serde_values(&data1, &data2, true, &[]).unwrap();
+//! assert!(!diffs.is_empty());
+//! // since we sorted for comparison, if we want to resolve the path, we need a sorted result as well.
+//! let data1_sorted = sort_value(&data1, &[]);
+//! let data2_sorted = sort_value(&data2, &[]);
+//! let all_diffs = diffs.all_diffs();
+//! assert_eq!(all_diffs.len(), 1);
+//! let (_type, diff) = all_diffs.first().unwrap();
+//! let val = diff.resolve(&data1_sorted);
+//! assert_eq!(val.unwrap().as_str().unwrap(), "f");
+//! let val = diff.resolve(&data2_sorted);
+//! assert_eq!(val.unwrap().as_str().unwrap(), "e");
+//! ```
 //!
 
-pub mod enums;
-pub mod mismatch;
-pub mod process;
-pub mod sort;
 pub use enums::DiffEntry;
 pub use enums::DiffTreeNode;
 pub use enums::DiffType;
 pub use enums::Error;
+pub use enums::PathElement;
 pub use mismatch::Mismatch;
 pub use process::compare_serde_values;
 pub use process::compare_strs;
+
+pub mod enums;
+pub mod mismatch;
+pub mod process;
+pub mod sort;
+
 pub type Result<T> = std::result::Result<T, Error>;