JSONDiffTool

JSONDiffTool is a Python application designed to compare two JSON states, detect updated fields, and help analyze how data changes after a user action.

Context

This project comes from a real need observed during an internship.
The goal was to compare JSON API responses before and after a user input in order to identify which fields were impacted, then track how these fields evolve during testing scenarios.

At first, this need was partially covered with Bash scripts:

• one script to compare a before state and an after state,
• one script to follow the evolution of the fields detected as changed.

JSONDiffTool is the Python version of this idea, with a cleaner structure and a user interface.

Main goal

The main objective of this project is to provide a simple tool that can:

• compare two JSON contents,
• detect changed, added, removed, or type-changed fields,
• display differences clearly,
• export results if needed.

V1 scope

The first version focuses on:

• a simple interface,
• two input areas for pasting JSON content,
• comparison of a before JSON and an after JSON,
• direct display of differences in the interface,
• optional CSV export of comparison results.

Planned improvements

Future versions may include:

• loading JSON files from the interface,
• tracking changed fields across multiple GET/PUT pairs,
• search for a specific field,
• comparison history,
• ignoring technical fields,
• advanced list handling.

Expected difference format

Each detected difference should contain at least:

• path
• change_type
• old_value
• new_value

Handled change types in V1:

• modified
• added
• removed
• type_changed

Project structure

JSONDiffTool/
├── app/
│   ├── __init__.py
│   ├── main.py
│   ├── core/
│   │   ├── __init__.py
│   │   └── comparator.py
│   ├── ui/
│   │   ├── __init__.py
│   │   └── interface.py
│   └── utils/
│       ├── __init__.py
│       └── json_loader.py
├── tests/
│   ├── __init__.py
│   └── test_comparator.py
├── sample_data/
│   ├── before.json
│   └── after.json
├── README.md
├── requirements.txt
└── .gitignore

Tech stack

• Python
• Streamlit for the interface
• Pytest for testing

Project status

V1 in progress.

Notes

All example JSON files used in this repository must be anonymized.