Moved the metadata into setup.cfg

Added `pyproject.toml`
Replaced fetching version from a file with fetching a version from version control system tags.
Also fixed a bug with incorrect content of `__all__` in `__main__.py`

Author: KOLANICH

.gitignore

@@ -1,3 +1,6 @@
+# autogenerated version file
+/pylsp_jsonrpc/_version.py
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

pylsp_jsonrpc/__init__.py

@@ -1,6 +1,21 @@
 # Copyright 2017-2020 Palantir Technologies, Inc.
 # Copyright 2021- Python Language Server Contributors.
 
+from . import _version
 from ._version import __version__
 
-__all__ = [__version__]
+def convert_version_info(version: str) -> (int, ..., str):
+    version_info = version.split(".")
+    for i in range(len(version_info)):
+        try:
+            version_info[i] = int(version_info[i])
+        except ValueError:
+            version_info[i] = version_info[i].split("+")[0]
+            version_info = version_info[:i + 1]
+            break
+
+    return tuple(version_info)
+
+_version.VERSION_INFO = convert_version_info(__version__)
+
+__all__ = ("__version__",)

pylsp_jsonrpc/_version.py

@@ -0,0 +1,7 @@
+[build-system]
+requires = ["setuptools>=44", "wheel", "setuptools_scm[toml]>=3.4.3"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools_scm]
+write_to = "pylsp_jsonrpc/_version.py"
+write_to_template = "__version__ = \"{version}\"\n"  # VERSION_INFO is populated in __main__

pyproject.toml

@@ -1,3 +1,32 @@
+[metadata]
+name = python-lsp-jsonrpc
+author = Python Language Server Contributors
+description = JSON RPC 2.0 server library
+url = https://github.com/python-lsp/python-lsp-jsonrpc
+long_description = file: README.md
+long_description_content_type = text/markdown
+
+
+[options]
+packages = find:
+setup_requires = setuptools>=44; wheel; setuptools_scm[toml]>=3.4.3
+install_requires = ujson>=3.0.0
+
+[options.packages.find]
+exclude =
+    contrib
+    docs
+    test
+    test.*
+
+[options.extras_require]
+test =
+    pylint
+    pycodestyle
+    pyflakes
+    pytest
+    pytest-cov
+    coverage
 
 [pycodestyle]
 ignore = E226, E722, W504