Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -2,29 +2,30 @@
 
 Thank you for investing time in our project!
 
-## Issues
+## 🐛 Issues
 
 Whether you have discovered a bug, want a new feature in Hurl, or change code, [please fill an issue] before any PR.
 We like to discuss things before implementation and want to be sure that: 
 
-- Any new features is coherent with Hurl core values
+- Any new features are coherent with Hurl core values
 - You don't waste time on a feature that will not fit Hurl
 - All options have been considered if possible
+- We try to minimize dependencies and import new crates parsimoniously
 
-## Pull Requests
+## 🥳 Pull Requests
 
 - Commits have to be signed.
 - All tests must be green before merge.
 - Hurl git history is linear, so we ask to rebase your PR before final merge. 
 
-## Hurl Core Values
+## ❤️ Hurl Core Values
 
 - Hurl is a first class citizen CLI tool, fast and reliable
 - Hurl is a cherry on the top of curl. What you can do with curl, you could do it with Hurl
 - Hurl file format is text plain, loosely based on HTTP
 - Hurl is multiplatform, working on Linux, macOS, Windows
 
-## How Can You Help ?
+## 👀 How Can You Help ?
 
 - Installing / Packet managers: bundle Hurl for a particular packet manager is welcome. Currently, we built binaries for
 Linux, macOS, Windows and we support a narrow set of packet manager. [More would be better!]
@@ -33,10 +34,61 @@ integrated way to run Hurl file would be cool also
 - [Documentation] is a never finished work and could be always improve. Don't hesitate to clarify, fix typos etc...
 - Report bugs: if possible some simple repro steps with the Hurl version, name of the platform etc...
 
+## 🤯 Build and Test
 
+Hurl is a Rust project, so you will need the Rust toolchain to build it. You can check the [Hurl build documentation] to 
+see how to build locally the latest version (master branch).
 
+Once your setup is ready, just build the project:
+
+```shell
+$ cargo build
+   Compiling hurl_core v2.0.0-SNAPSHOT (/Users/jc/Documents/Dev/hurl/packages/hurl_core)
+   ...
+   Compiling hurlfmt v2.0.0-SNAPSHOT (/Users/jc/Documents/Dev/hurl/packages/hurlfmt)
+   Compiling hurl v2.0.0-SNAPSHOT (/Users/jc/Documents/Dev/hurl/packages/hurl)
+    Finished dev [unoptimized + debuginfo] target(s) in 2.53s
+```
+
+Hurl unit and integration tests need Python 3.6+ to be run. You can use a [virtual environment] and install the dependencies needed
+by the tests suite:
+
+```shell
+$ python3 -m venv .venv
+$ source .venv/bin/activate
+$ pip3 install --requirement bin/requirements-frozen.txt
+```
+
+Then, you can launch our local server (used to test Hurl features):
+
+```shell
+$ cd integration
+$ python3 server.py >server.log 2>&1 &
+$ python3 ssl/server.py >server-ssl.log 2>&1 &
+$ mitmdump --listen-host 127.0.0.1 --listen-port 8888 --modify-header "/From-Proxy/Hello" >mitmdump.log 2>&1 &
+$ jobs
+[1]    running    python3 server.py > server.log 2>&1
+[2]  - running    python3 ssl/server.py > server-ssl.log 2>&1
+[3]  + running    mitmdump --listen-host 127.0.0.1 --listen-port 8888 --modify-header  >  2>&1
+```
+
+You can check [`bin/test/test_prerequisites.sh`] and [`bin/test/test_prerequisites.ps1`] for more details.
+
+Now, you can follow these steps when you make changes:
+
+1. Build `cargo build`
+2. Run Clippy `cargo clippy`
+3. Format `cargo fmt`
+4. Run units tests `cargo test`
+5. Run integration tests `cd integration && python3 integration.py`
+
+Et voilà 🎉! 
 
 
 [please fill an issue]: https://github.com/Orange-OpenSource/hurl/issues
 [More would be better!]: https://github.com/BurntSushi/ripgrep#installation
 [Documentation]: https://github.com/BurntSushi/ripgrep#installation
+[Hurl build documentation]: https://hurl.dev/docs/installation.html#building-from-sources
+[`bin/test/test_prerequisites.sh`]: /bin/test/test_prerequisites.sh
+[`bin/test/test_prerequisites.ps1`]: /bin/test/test_prerequisites.ps1
+[virtual environment]: https://docs.python.org/3/tutorial/venv.html