Implement black and isort-based style checks

.flake8

@@ -1,4 +1,5 @@
 [flake8]
+max-line-length = 88
 exclude = examples,build
-ignore = E266, W503
+ignore = E203, E266, W503
 per-file-ignores = */api.py:F401

.github/workflows/check-style.yml

@@ -0,0 +1,20 @@
+name: Run style checks
+
+on: [pull_request, workflow_dispatch]
+
+jobs:
+  style:
+    runs-on: 'ubuntu-latest'
+
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-python@v4
+      with:
+        python-version: '3.11'
+        cache: 'pip'
+        cache-dependency-path: '.github/workflows/style-requirements.txt'
+    - run: python -m pip install -r .github/workflows/style-requirements.txt
+    - run: |
+        python -m black --check --diff .
+        python -m isort --check --diff .
+        python -m flake8 .

.github/workflows/style-requirements.txt

@@ -0,0 +1,4 @@
+black ~= 23.0
+flake8
+flake8-ets
+isort

.github/workflows/test-with-edm.yml

@@ -45,9 +45,6 @@ jobs:
         run: python -m pip install -r .github/workflows/bootstrap-requirements.txt
       - name: Install test environment
         run: python etstool.py install --runtime=${{ matrix.runtime }} --toolkit=${{ matrix.toolkit }}
-      - name: Flake8
-        run: python etstool.py flake8 --runtime=${{ matrix.runtime }} --toolkit=${{ matrix.toolkit }}
-        if: runner.os == 'Linux' && matrix.toolkit == 'null'
       - name: Run tests (Ubuntu)
         if: matrix.os == 'ubuntu-latest'
         run: xvfb-run -a python etstool.py test --runtime=${{ matrix.runtime }} --toolkit=${{ matrix.toolkit }}

etstool.py

@@ -106,8 +106,6 @@
     "apptools",
     "coverage",
     "enthought_sphinx_theme",
-    "flake8",
-    "flake8_ets",
     "pyface",
     "sphinx",
     "sphinx_copybutton",
@@ -116,7 +114,14 @@
 }
 
 # Dependencies we install from PyPI
-pypi_dependencies = {}
+pypi_dependencies = {
+    # style packages; install from PyPI to make sure that we're compatible
+    # with the style checks used in the check-style.yml workflow
+    "black~=23.0",
+    "flake8",
+    "flake8-ets",
+    "isort",
+}
 
 # Dependencies we install from source for cron tests
 # Order from packages with the most dependencies to one with the least
@@ -187,6 +192,16 @@ def cli():
     pass
 
 
+# Subgroup for checking and fixing style
+
+
+@cli.group()
+def style():
+    """
+    Commands for checking style and applying style fixes.
+    """
+
+
 @cli.command()
 @edm_option
 @runtime_option
@@ -275,17 +290,42 @@ def shell(edm, runtime, toolkit, environment):
     execute(commands, parameters)
 
 
-@cli.command()
+@style.command(name="check")
 @edm_option
 @runtime_option
 @toolkit_option
 @environment_option
-def flake8(edm, runtime, toolkit, environment):
-    """ Run a flake8 check in a given environment.
+def style_check(edm, runtime, toolkit, environment):
+    """
+    Run style checks.
+    """
+    parameters = get_parameters(edm, runtime, toolkit, environment)
+    commands = [
+        "{edm} run -e {environment} -- python -m black --check --diff .",
+        "{edm} run -e {environment} -- python -m isort --check --diff .",
+        "{edm} run -e {environment} -- python -m flake8 .",
+    ]
+    execute(commands, parameters)
+
+
+@style.command(name="fix")
+@edm_option
+@runtime_option
+@toolkit_option
+@environment_option
+def style_fix(edm, runtime, toolkit, environment):
+    """
+    Run style fixers.
 
+    This automatically fixes any black or isort failures, but it won't
+    automatically fix all flake8 errors.
     """
     parameters = get_parameters(edm, runtime, toolkit, environment)
-    commands = ["{edm} run -e {environment} -- python -m flake8"]
+    commands = [
+        "{edm} run -e {environment} -- python -m black .",
+        "{edm} run -e {environment} -- python -m isort .",
+        "{edm} run -e {environment} -- python -m flake8 .",
+    ]
     execute(commands, parameters)
 
 

pyproject.toml

@@ -48,11 +48,11 @@ repository = 'https://github.com/enthought/envisage'
 issues = 'https://github.com/enthought/envisage/issues'
 
 [tool.black]
-line-length = 79
+line-length = 88
 
 [tool.isort]
 profile = 'black'
-line_length = 79
+line_length = 88
 order_by_type = false
 sections = ['FUTURE', 'STDLIB', 'THIRDPARTY', 'ENTHOUGHT', 'FIRSTPARTY', 'LOCALFOLDER']
 known_enthought = ['apptools', 'pyface', 'traits', 'traitsui']