Testing

.github/workflows/test.yml

@@ -0,0 +1,72 @@
+# Run this job on pushes to `main`, and for pull requests. If you don't specify
+# `branches: [main], then this actions runs _twice_ on pull requests, which is
+# annoying.
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      # If you wanted to use multiple Python versions, you'd have specify a matrix in the job and
+      # reference the matrixe python version here.
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+
+      # Cache the installation of Poetry itself, e.g. the next step. This prevents the workflow
+      # from installing Poetry every time, which can be slow. Note the use of the Poetry version
+      # number in the cache key, and the "-0" suffix: this allows you to invalidate the cache
+      # manually if/when you want to upgrade Poetry, or if something goes wrong. This could be
+      # mildly cleaner by using an environment variable, but I don't really care.
+      - name: cache poetry install
+        uses: actions/cache@v2
+        with:
+          path: ~/.local
+          key: poetry-1.5.1-0
+
+      # Install Poetry. You could do this manually, or there are several actions that do this.
+      # `snok/install-poetry` seems to be minimal yet complete, and really just calls out to
+      # Poetry's default install script, which feels correct. I pin the Poetry version here
+      # because Poetry does occasionally change APIs between versions and I don't want my
+      # actions to break if it does.
+      #
+      # The key configuration value here is `virtualenvs-in-project: true`: this creates the
+      # venv as a `.venv` in your testing directory, which allows the next step to easily
+      # cache it.
+      - uses: snok/install-poetry@v1
+        with:
+          version: 1.5.1
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+
+      # Cache your dependencies (i.e. all the stuff in your `pyproject.toml`). Note the cache
+      # key: if you're using multiple Python versions, or multiple OSes, you'd need to include
+      # them in the cache key. I'm not, so it can be simple and just depend on the poetry.lock.
+      - name: cache deps
+        id: cache-deps
+        uses: actions/cache@v2
+        with:
+          path: .venv
+          key: pydeps-${{ hashFiles('**/poetry.lock') }}
+
+      # Install dependencies. `--no-root` means "install all dependencies but not the project
+      # itself", which is what you want to avoid caching _your_ code. The `if` statement
+      # ensures this only runs on a cache miss.
+      - run: poetry install --no-interaction --no-root
+        if: steps.cache-deps.outputs.cache-hit != 'true'
+
+      # Now install _your_ project. This isn't necessary for many types of projects -- particularly
+      # things like Django apps don't need this. But it's a good idea since it fully-exercises the
+      # pyproject.toml and makes that if you add things like console-scripts at some point that
+      # they'll be installed and working.
+      - run: poetry install --no-interaction
+
+      # And finally run tests. I'm using pytest and all my pytest config is in my `pyproject.toml`
+      # so this line is super-simple. But it could be as complex as you need.
+      - run: poetry run pytest

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "discogs-tag"
-version = "0.1.4"
+version = "0.1.5"
 description = "A rudimentary audio tagger based on Discogs metadata."
 authors = ["infojunkie <[email protected]>"]
 readme = "README.md"
@@ -12,9 +12,16 @@ fire = "^0.5.0"
 mutagen = "^1.46.0"
 importlib-metadata = "^6.8.0"
 
+[tool.poetry.group.dev.dependencies]
+pytest = "^7.0.0"
+pytest-mock = "*"
+
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
 [tool.poetry.scripts]
 discogs-tag = "discogs_tag.cli:cli"
+
+[tool.pytest.ini_options]
+pythonpath = "src"

src/discogs_tag/cli.py

@@ -23,16 +23,7 @@ def tag(release, dir = './', dry = False):
       raise Exception(f'Expecting {len(tracks)} files but found {len(files)}. Aborting.')
     for n, track in enumerate(tracks):
       audio = mutagen.File(files[n], easy=True)
-      audio['title'] = track['title']
-      if 'artists' in track:
-        audio['artist'] = ', '.join([artist_name(artist) for artist in track['artists']])
-      positions = track['position'].split('-')
-      audio['tracknumber'] = positions[-1]
-      if (len(positions) > 1):
-        audio['discnumber'] = positions[0]
-      composers = ', '.join([artist_name(composer) for composer in filter(lambda a: a['role'].casefold() == 'Written-By'.casefold(), track['extraartists'])]) if 'extraartists' in track else None
-      if (composers):
-        audio['composer'] = composers
+      apply_metadata(track, audio)
       if (dry):
         pprint(audio)
       else:
@@ -41,8 +32,25 @@ def tag(release, dir = './', dry = False):
     if (not dry):
       print(f'Processed {len(files)} audio files.')
 
+def apply_metadata(track, audio):
+  audio['title'] = track['title']
+  if 'artists' in track:
+    audio['artist'] = ', '.join([artist_name(artist) for artist in track['artists']])
+  positions = track['position'].split('-')
+  audio['tracknumber'] = positions[-1]
+  if (len(positions) > 1):
+    audio['discnumber'] = positions[0]
+  composers = ', '.join([artist_name(composer) for composer in filter(lambda a: a['role'].casefold() == 'Written-By'.casefold(), track['extraartists'])]) if 'extraartists' in track else None
+  if (composers):
+    audio['composer'] = composers
+
 def artist_name(artist):
-  return artist['anv'] or artist['name']
+  if 'anv' in artist:
+    return artist['anv']
+  elif 'name' in artist:
+    return artist['name']
+  else:
+    return None
 
 def cli():
   fire.Fire(tag)

tests/test_discogs_tag.py

@@ -0,0 +1,25 @@
+from discogs_tag.cli import apply_metadata
+
+def test_apply_metadata():
+  audio = {}
+  apply_metadata({
+    'title': 'Title',
+    'artists': [{
+      'anv': 'Artist 1'
+    }, {
+      'name': 'Artist 2'
+    }],
+    'position': '1-02',
+    'extraartists': [{
+      'role': 'Guitar',
+      'name': 'Guitarist'
+    }, {
+      'role': 'Written-By',
+      'name': 'Composer'
+    }]
+  }, audio)
+  assert audio['title'] == 'Title'
+  assert audio['artist'] == 'Artist 1, Artist 2'
+  assert audio['discnumber'] == '1'
+  assert audio['tracknumber'] == '02'
+  assert audio['composer'] == 'Composer'