Add a basic pre-commit lint and autoformat

[adehad]

Following up on: https://github.com/edgedb/edgedb-python/issues/438

Summary of changes

1. a pre-commit config file has been added with some simple rules
2. Errors picked up during the linting have been addressed and added as separate commits for clarity

NOTE

Target branch

~~This is targetting the drop-py37 branch. As it was assumed this PR would be merged after #435 .~~

Running the lint

The assumption is that pre-commit.ci GitHub integration is going to be setup for this project and therefore a dedicate lint GHA has NOT been setup, although it may look like:

---
name: Lint

on:
  push:
    branches:
      - master
      - ci
  pull_request:
    branches:
      - master
  workflow_dispatch:
    inputs: {}

jobs:
  test:
    runs-on: ubuntu-latest

    defaults:
      run:
        shell: bash

    env:
      PIP_DISABLE_PIP_VERSION_CHECK: 1

    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 1
          submodules: true

      - name: pre-commit
        run: |
          python -m pip install pre-commit
          python -m pre_commit run --all-files

[gel-data-cla[bot]]

All commit authors signed the Contributor License Agreement.

[adehad]

@fantix Might be an issue that tests aren't running on this PR yet (due to it not targetting the master branch). Happy to wait for #435 to be merged first

[chrisemke]

Another thing that would be really cool would be an edgedb hook to (but not limited to) verifying or formatting the .esdl and .edgeql files

[adehad]

@fantix feel free commit any of the suggestions. (Personally I don't think the name addition to the pre-commit config adds much, I've mainly used it when I am running the same tool multiple times but with different configurations)

[fantix]

Sorry, I didn't mean to close this PR.

[adehad]

@fantix do let me know if you would like me to target the main branch instead of this drop-py37 branch

[fantix]

Yes, please! Let's retarget and rebase to the master branch, and get this merged 🙏

[adehad]

@fantix should be ready for review again now

[adehad]

Didn't realise there were merge conflicts, should now be resolved and ready for review @fantix

[adehad]

(bump) @fantix

[adehad]

@fantix have just rebased now

[fantix]

Thanks for the updates! I talked to the team and decided we don't want a pre-commit hook yet. However, I think the formatted code could stay (with a few nitpicking, for which I'll add comments on this PR) and we can probably have a test that runs the linter and formatter for checking.

[adehad]

and we can probably have a test that runs the linter and formatter for checking.

Yep, we do this too rather that as a pre-commit hook itself. I can recommend using the pre-commit.ci github action/app as this automates the process of checking PRs