Add spell checking to CircleCI via aspell.

Install aspell on CircleCI. Add a custom dictionary file.

Spell check the Markdown files in the repository root.

Add section on spell checking to the contributing guide.

Update the CHANGELOG.

Author: jbampton

.aspell.en.pws

@@ -0,0 +1,135 @@
+personal_ws-1.1 en 134
+APIs
+ActionChain
+AppProvider
+CDN
+CHANGELOG
+CSRF
+CircleCI
+Clientside
+ComponentRegistry
+Crossfiltering
+DOM
+DataFrame
+DependencyException
+Dev
+Dropdown
+Homebrew
+IDEs
+InvalidIndexException
+InvalidResourceError
+JS
+JSON
+KeyError
+LGTM
+MacOS
+MacPorts
+Mapbox
+MutableMapping
+Plotly
+Plotly's
+Plotlyers
+PreventUpdate
+PropTypes
+PyPI
+README
+Redux
+Renderer
+ResourceException
+Submodules
+TreeContainer
+UI
+WebDriver
+abc
+analytics
+api
+arg
+args
+aspell
+async
+asyncDecorator
+auth
+backend
+backends
+cd
+cheatsheet
+chris
+cli
+clientside
+compat
+config
+configs
+coord
+css
+customizable
+cwd
+dashR
+dashr
+dcc
+defaultdict
+dev
+devtools
+docgen
+docstring
+docstrings
+dom
+dropdown
+dropdowns
+elif
+endline
+environ
+etag
+favicon
+formatter
+frontend
+gunicorn
+hocho
+html
+http
+ie
+init
+javascript
+js
+json
+kwargs
+lang
+localhost
+ly
+md
+middleware
+montreal
+msec
+namespace
+namespaces
+npm
+pathname
+pathnames
+percy
+plotly
+polyfills
+py
+pylint
+pytest
+redux
+renderer
+repo
+repos
+repr
+scalability
+serializable
+setProps
+sexualized
+src
+supress
+tada
+tracebacks
+ui
+unittest
+updateProps
+url
+urls
+utf
+venv
+virtualenv
+walmart
+whatwg

.circleci/config.yml

@@ -38,6 +38,8 @@ jobs:
       - run:
           name: ️️🏗️ pip dev requirements
           command: |
+            sudo apt update
+            sudo apt install aspell
             sudo pip install --upgrade virtualenv --progress-bar off
             python -m venv venv || virtualenv venv && . venv/bin/activate
             pip install -e . --no-cache-dir -r requires-install.txt -r requires-dev.txt -r requires-testing.txt --progress-bar off
@@ -46,7 +48,7 @@ jobs:
           paths:
               - venv
       - run:
-          name: 🌸 Python & JS Lint
+          name: 🌸 Python & JS Lint, Check Spelling
           command: |
             . venv/bin/activate
             set -eo pipefail
@@ -56,6 +58,8 @@ jobs:
             pylint tests/unit tests/integration/devtools tests/integration/renderer tests/integration/dash_assets -d all -e C0410,C0411,C0412,C0413,W0109
             cd dash-renderer && npm ci
             npm run lint:test && npm run format:test
+            cd ..
+            cat *.md | aspell --mode=markdown --lang=en --encoding=utf-8 --personal=./.aspell.en.pws list | sort -u && exit 0
       - run:
           name: 🐍 Python Unit Tests
           command: |

CHANGELOG.md

@@ -5,6 +5,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ## Unreleased
 
 ### Added
+- [#1081](https://github.com/plotly/dash/pull/1081) Add spell checking for Markdown files to CircleCI via GNU Aspell.
 - [#1073](https://github.com/plotly/dash/pull/1073) Two new functions to simplify usage handling URLs and pathnames: `app.get_relative_path` & `app.trim_relative_path`.
 These functions are particularly useful for apps deployed on Dash Enterprise where the apps served under a URL prefix (the app name) which is unlike apps served on localhost:8050.
     - `app.get_relative_path` returns a path with the config setting `requests_pathname_prefix` prefixed. Use `app.get_relative_path` anywhere you would provide a relative pathname, like `dcc.Link(href=app.relative_path('/page-2'))` or even as an alternative to `app.get_asset_url` with e.g. `html.Img(src=app.get_relative_path('/assets/logo.png'))`.

CONTRIBUTING.md

@@ -100,6 +100,22 @@ We use both `flake8` and `pylint` for basic linting check, please refer to the r
 
 Note that we also start using [`black`](https://black.readthedocs.io/en/stable/) as formatter during the test code migration.
 
+### Spell Checking
+
+We use [GNU Aspell](http://aspell.net/) to check the spelling of the Markdown files in the repository root. GNU Aspell is a free and open source spell checker designed to eventually replace Ispell. It compiles for Unix-like operating systems and Windows. Refer to the relevant step in `.circleci/config.yml` to see the Aspell implementation. 
+
+Aspell can also be installed on MacOS via [Homebrew](https://formulae.brew.sh/formula/aspell) and with [MacPorts](https://www.macports.org/ports.php?by=library&substr=aspell) and includes a man page:
+
+```
+man aspell
+```
+
+We check spelling and print out a list of words not in our dictionary and we don't fail the build if new words are found:
+
+```
+cat *.md | aspell --mode=markdown --lang=en --encoding=utf-8 --personal=./.aspell.en.pws list | sort -u && exit 0
+```
+
 ## Tests
 
 We started migrating to [pytest](https://docs.pytest.org/en/latest/) from `unittest` as our test automation framework. You will see more testing enhancements in the near future.

requires-dev.txt

@@ -8,4 +8,4 @@ pylint==2.3.1;python_version=="3.7"
 astroid==2.2.5;python_version=="3.7"
 virtualenv;python_version=="2.7"
 fire
-coloredlogs
+coloredlogs