packaging: switch back to requirements.txt

The pyproject.toml spec is highly opinionated about installing
dependencies. As such, locally development is unpleasant when running
pip install . since it will always install the package, not just our
depends. This complicates testing "the right changes".

To promote a better experience, return to using requirements files and
make pyproject.toml depend on them dynamically so we don't have to
maintain the information in multiple places.

Signed-off-by: Cory Todd <cory.todd@canonical.com>

README.rst

@@ -94,3 +94,26 @@ Examples:
     $ jdiff a.json b.json -i 2 -s symmetric
 
     $ jdiff a.yaml b.yaml -f yaml -s symmetric
+
+Development
+-----------
+
+Install development dependencies and test locally with
+
+.. code-block:: bash
+
+    pip install -r requirements-dev.txt
+    # ... do your work ... add tests ...
+    pytest
+
+Installing From Source
+----------------------
+
+To install from source run
+
+.. code-block:: bash
+
+    pip install .
+
+This will install the library and cli for `jsondiff` as well as its runtime
+dependencies.

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "jsondiff"
 description = "Diff JSON and JSON-like structures in Python"
-dynamic = ["version"]
+dynamic = ["version", "dependencies", "optional-dependencies"]
 readme = "README.rst"
 license= {file = "LICENSE" }
 requires-python = ">=3.8"
@@ -17,15 +17,6 @@ classifiers = [
     'License :: OSI Approved :: MIT License',
     'Programming Language :: Python :: 3',
 ]
-dependencies = [
-    "pyyaml"
-]
-
-[project.optional-dependencies]
-test = [
-    "hypothesis",
-    "pytest"
-]
 
 [project.urls]
 "Homepage" = "https://github.com/xlwings/jsondiff"
@@ -40,3 +31,7 @@ exclude = ["tests*"]
 
 [tool.setuptools.dynamic]
 version = {attr = "jsondiff.__version__"}
+dependencies = {file=["requirements.txt"]}
+
+[tool.setuptools.dynamic.optional-dependencies]
+dev = {file=["requirements-dev.txt"]}

requirements-dev.txt

@@ -0,0 +1,2 @@
+hypothesis
+pytest

requirements.txt

@@ -0,0 +1 @@
+pyyaml