Use hatchling to build distribution (#1112)

* refactor(packaging): use hatchling to build package

This includes a custom build hook to build our frontend js & css

* refactor(ci): use pypa/gh-action-pypi-publish action

* refactor(ci): move publish job to the ci workflow

This accomplishes two things:

- Ensures that tests pass before publishing
- On each workflow run, tests that the packaging works

* test(ci): upload built wheel and sdist for examination

* refactor(packaging): delete build-dist testenv from tox config

* refactor(packaging): remove dist and upload targets from Makefile

* docs(README): update the development instructions

.github/workflows/ci.yml

@@ -6,6 +6,8 @@ on:
     branches:
       - master
       - "*-maintenance"
+    tags:
+      - "v*"
   pull_request:
     branches:
       - master
@@ -33,7 +35,7 @@ jobs:
         with:
           python-version: "3.9"
           cache: "pip"
-          cache-dependency-path: "**/setup.cfg"
+          cache-dependency-path: "**/pyproject.toml"
       - uses: actions/cache@v3
         with:
           path: ~/.cache/pre-commit
@@ -54,7 +56,7 @@ jobs:
   ############################################################################
   # Node tests
   ############################################################################
-  node:
+  node-tests:
     name: ${{ matrix.os}} node-${{ matrix.node }}
     runs-on: ${{ matrix.os }}
     strategy:
@@ -110,7 +112,7 @@ jobs:
         with:
           python-version: ${{ matrix.python }}
           cache: "pip"
-          cache-dependency-path: "**/setup.cfg"
+          cache-dependency-path: "**/pyproject.toml"
 
       - name: Install Linux system dependencies
         if: runner.os == 'Linux' && matrix.install-ffmpeg
@@ -139,3 +141,38 @@ jobs:
         run: tox
       - name: Publish coverage data to codecov
         uses: codecov/codecov-action@v3
+
+  ############################################################################
+  # Package and (Possibly) Publish to PyPI
+  ############################################################################
+  deploy:
+    needs: ["lint", "node-tests", "python-tests"]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@v4
+      - uses: actions/setup-node@v3
+        with:
+          node-version: "lts/*"
+
+      - name: Install dependencies
+        run: python -m pip install build
+
+      - name: Build release artifacts
+        env:
+          HATCH_BUILD_CLEAN: "true"
+        run: python -m build
+
+      - name: Save release artifacts (for inspection)
+        uses: actions/upload-artifact@v3
+        with:
+          name: dist
+          path: dist/*
+
+      - name: Publish release
+        if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_PASSWORD }}

Makefile

@@ -37,14 +37,3 @@ test: lint test-python test-js
 test-all: test-js
 	pre-commit run -a
 	tox
-
-# This creates source distribution and a wheel.
-dist: build-js setup.cfg MANIFEST.in
-	rm -rf build dist
-	python -m build
-
-# Before making a release, CHANGES.md needs to be updated and
-# a tag should be created (and pushed with `git push --tags`).
-.PHONY: upload
-upload: dist
-	twine upload dist/*

README.md

@@ -28,24 +28,31 @@ For installation instructions head to the official documentation:
 
 ## Want to develop on Lektor?
 
-This gets you started (assuming you have Python, pip, Make and pre-commit
+This gets you started (assuming you have Python, pip, npm, and pre-commit
 installed):
 
-```
+```bash
 $ git clone https://github.com/lektor/lektor
 $ cd lektor
-$ virtualenv venv
-$ . venv/bin/activate
+$ python -m venv _venv
+$ . _venv/bin/activate
+
+# pip>=21.3 is required for PEP 610 support
+$ pip install -U "pip>=21.3"
+
 $ pip install --editable .
-$ make build-js
+
+# If you plan on committing:
 $ pre-commit install
+
+# Run the Lektor server
 $ export LEKTOR_DEV=1
 $ cp -r example example-project
 $ lektor --project example-project server
 ```
 
 If you want to run the test suite (you'll need tox installed):
 
-```
+```sh
 $ tox
 ```

build_frontend.py

@@ -0,0 +1,80 @@
+"""A hatch build-hook that builds the front-end js/css at PEP 517 build time.
+
+By default, when building the dist, if the built frontend code is not
+present in the source directory, it will be built.  (Node must be installed,
+or this will fail.)
+
+Environment Variables
+---------------------
+
+There are a couple of environment variables that can be used to provide
+additional control over the building of the frontend code.
+
+- ``HATCH_BUILD_NO_HOOKS=true``: skip building the frontend code
+- ``HATCH_BUILD_CLEAN=true``: force (re)building of the frontend code
+
+"""
+import shutil
+import subprocess
+from pathlib import Path
+
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
+
+# path to frontend source
+FRONTEND = "frontend"
+
+# path to compiled JS entry point
+APP_JS = "lektor/admin/static/app.js"
+
+
+class FrontendBuildHook(BuildHookInterface):
+    """Hatching build hook to compile our frontend JS."""
+
+    def clean(self, versions):
+        """Called at the beginning of each PEP 517 build, if HATCH_BUILD_CLEAN is set.
+
+        This implementation deletes any compiled frontend code that may be present
+        in the source tree.
+        """
+        app = self.app
+        root = self.root
+
+        if not Path(root, FRONTEND).is_dir():
+            app.display_info(
+                "frontend source missing, skipping cleaning compiled output"
+            )
+            return
+
+        output_path = Path(root, APP_JS).parent
+        app.display_info(f"cleaning {output_path.relative_to(root)}")
+        if output_path.is_dir():
+            shutil.rmtree(output_path)
+
+    def initialize(self, version, build_data):
+        """Hook called before each package build.
+
+        This implementation builds the compiled frontend source, but only
+        if it is not already present in the source tree.
+
+        Node (and npm) must be installed or this step will fail.
+        """
+        app = self.app
+        root = self.root
+
+        if Path(root, APP_JS).is_file():
+            app.display_info(f"{APP_JS} exists, skipping frontend build")
+            return
+
+        npm = shutil.which("npm")
+        if npm is None:
+            app.abort("npm is not available. can not build frontend")
+
+        frontend = Path(root, FRONTEND)
+        if not frontend.is_dir():
+            app.abort("frontend source is missing. can not build frontend")
+
+        app.display_info("npm install")
+        subprocess.run((npm, "install"), cwd=frontend, check=True)
+        app.display_info("npm run build")
+        subprocess.run((npm, "run", "build"), cwd=frontend, check=True)
+        app.display_success("built frontend static files")

pyproject.toml

@@ -1,8 +1,91 @@
 [build-system]
-requires = ["setuptools>=45", "setuptools_scm>=6.2"]
-build-backend = "setuptools.build_meta"
+requires = ["hatchling>=1.13.0,<2.0.0", "hatch-vcs"]
+build-backend = "hatchling.build"
+
+[project]
+name = "Lektor"
+description = "A static content management system."
+dynamic = ["version"]
+readme = "README.md"
+license = { file = "LICENSE" }
+authors = [
+    { name = "Armin Ronacher", email = "armin.ronacher@active-4.com" },
+]
+urls.Homepage = "https://www.getlektor.com/"
+urls.Source = "https://github.com/lektor/lektor/"
+urls.Documentation = "https://www.getlektor.com/docs/"
+urls.Changelog = "https://github.com/lektor/lektor/blob/master/CHANGES.md"
+classifiers = [
+    "Framework :: Lektor",
+    "Environment :: Web Environment",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: BSD License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Topic :: Internet :: WWW/HTTP :: Dynamic Content",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+]
+
+requires-python = ">=3.7"
+dependencies = [
+    "Babel",
+    "click>=6.0",
+    "EXIFRead",
+    "filetype>=1.0.7",
+    "Flask",
+    "importlib_metadata; python_version<'3.8'",
+    "inifile>=0.4.1",
+    "Jinja2>=3.0",
+    "MarkupSafe",
+    "marshmallow",
+    "marshmallow_dataclass>=8.5.9",
+    "mistune>=0.7.0,<3",
+    "pip",
+    "python-slugify",
+    "pytz; python_version<'3.9'",  # favor zoneinfo for python>=3.9
+    "requests",
+    "tzdata; python_version>='3.9' and sys_platform == 'win32'",
+    "watchdog",
+    "Werkzeug>=2.1.0,<3",
+]
+optional-dependencies.ipython = [
+    "ipython",
+    "traitlets",
+]
+
+[project.scripts]
+lektor = "lektor.cli:main"
+
+[tool.hatch.version]
+source = "vcs"
+
+[tool.hatch.build]
+include = [
+    "/lektor",
+]
+artifacts = [
+    "/lektor/admin/static",
+]
+
+[tool.hatch.build.targets.sdist]
+include = [
+    "/lektor",
+    "/build_frontend.py",
+    "/CHANGES.md",
+    "/tests",
+    "/tox.ini",
+]
+
+[tool.hatch.build.hooks.custom]
+path = "build_frontend.py"
+
 
-[tool.setuptools_scm]
 
 ################################################################
 #