Implement test automation (nox) and linting and typing through pre-commit. Resolves #22

[davidverweij]

This PR implements linting, typing and tests such that upcoming contributions are sound - this should help with error prevention in the long run.

More specifically, changes include (as suggested in #22):

• set up nox for test automation
• set up nox session to run:
  • flake8 linting
  • pytests unit testing
  • mypy type testing
  • isort import statement ordering
  • black automatic code formatting
• set up pre-commit to run (and mandate passes) for these, except pytests.

As expected, these prompted a breadth of required changes which are all resolved. A few simply cannot due to our setup, and have been added to config files for mypy and flake8 to be ignored.

Test

• pull down this branch
• run poetry install to include dev dependencies
• enter a virtual environment (poetry shell)
• set up pre-commit hooks: pre-commit install
• run individual check:
  • poetry run nox -rs tests. This runs all tests (and currently fails a few on the inventory part). Note that it currently circumvents `install_withconstraints. See issue #36.
  • poetry run nox -rs mypy. This checks typing. Note that a few tests are currently excluded (see issue #35).
  • poetry run nox -rs isort. This sorts import statements alphabetically and by sections (i.e. global, 3rd party and local)
  • poetry run nox -rs lint. This runs various linting checks using flake8. Note that a few errors are ignored for our use case - see mypy.ini in root.
  • poetry run nox -rs black. This checks and changes various formatting following black standards.
• to test pre-commit functionality, make a simple change and commit. This should run (and pass)
  • Check Yaml
  • Trim Trailing Whitespace
  • black
  • flake8
  • isort, and
  • mypy

To Do

As referred to above, a few issues and todo's arose from the adoption of linting, tests and typing. These are documented in separate issues to work on.

[lgtm-com[bot]]

This pull request fixes 9 alerts when merging 833a99c7ae22edf5e5c3ee8a16dbcfc12ced49ad into a6ba0ad3e9040a0c6efd78ca4c2caf4adcf28264 - view on LGTM.com

fixed alerts:

• 8 for Unused import
• 1 for Unused local variable

[lgtm-com[bot]]

This pull request fixes 9 alerts when merging e7fdbf100c1eb71f79d3b3d04f8a3b9e4f8c276e into a6ba0ad3e9040a0c6efd78ca4c2caf4adcf28264 - view on LGTM.com

fixed alerts:

• 8 for Unused import
• 1 for Unused local variable

[lgtm-com[bot]]

This pull request fixes 9 alerts when merging b349d2fd487456563b2449ea294d14126d9fc4af into a6ba0ad3e9040a0c6efd78ca4c2caf4adcf28264 - view on LGTM.com

fixed alerts:

• 8 for Unused import
• 1 for Unused local variable

[jawrainey]

LGTM and pytest via nox now returns correct state