Add unit test coverage report to pre-merge (#1064)

Author: ericj-db

.github/workflows/coverage.yml

@@ -0,0 +1,33 @@
+# .github/workflows/coverage.yml
+name: Post coverage comment
+
+on:
+  workflow_run:
+    workflows: ["Tests and Code Checks"]
+    types:
+      - completed
+
+jobs:
+  test:
+    name: Run tests & display coverage
+    runs-on: linux-ubuntu-latest
+    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
+    permissions:
+      # Gives the action the necessary permissions for publishing new
+      # comments in pull requests.
+      pull-requests: write
+      # Gives the action the necessary permissions for editing existing
+      # comments (to avoid publishing multiple comments in the same PR)
+      contents: write
+      # Gives the action the necessary permissions for looking up the
+      # workflow that launched this workflow, and download the related
+      # artifact that contains the comment to be published
+      actions: read
+    steps:
+      # DO NOT run actions/checkout here, for security reasons
+      # For details, refer to https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
+      - name: Post comment
+        uses: py-cov-action/python-coverage-comment-action@v3
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_PR_RUN_ID: ${{ github.event.workflow_run.id }}

.github/workflows/main.yml

@@ -44,7 +44,7 @@ jobs:
   code-quality:
     name: Code Quality
 
-    runs-on: ubuntu-latest
+    runs-on: linux-ubuntu-latest
     timeout-minutes: 10
 
     strategy:
@@ -68,8 +68,17 @@ jobs:
   unit:
     name: unit test / python ${{ matrix.python-version }}
 
-    runs-on: ubuntu-latest
-    timeout-minutes: 10
+    runs-on: linux-ubuntu-latest
+    timeout-minutes: 15
+
+    permissions:
+      # Gives the action the necessary permissions for publishing new
+      # comments in pull requests.
+      pull-requests: write
+      # Gives the action the necessary permissions for pushing data to the
+      # python-coverage-comment-action branch, and for editing existing
+      # comments (to avoid publishing multiple comments in the same PR)
+      contents: write
 
     strategy:
       fail-fast: false
@@ -88,12 +97,26 @@ jobs:
       - name: Install Hatch
         uses: pypa/hatch@install
 
-      - name: Run Unit Tests
-        run: hatch run -v +py=${{ matrix.python-version }} test:unit
+      - name: Run Unit Tests and Generate Coverage
+        run: hatch run -v +py=${{ matrix.python-version }} test:unit-with-cov
+
+      # Only run coverage comment once (not for all python versions)
+      - name: Coverage Comment
+        if: matrix.python-version == '3.12' && github.event_name == 'pull_request'
+        uses: py-cov-action/python-coverage-comment-action@v3
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Store Pull Request comment to be posted
+        uses: actions/upload-artifact@v4
+        if: steps.coverage_comment.outputs.COMMENT_FILE_WRITTEN == 'true'
+        with:
+          name: python-coverage-comment-action
+          path: python-coverage-comment-action.txt
 
   build:
     name: Build and Verify Packages
-    runs-on: ubuntu-latest
+    runs-on: linux-ubuntu-latest
 
     steps:
       - name: Check out the repository

.gitignore

@@ -20,3 +20,4 @@ logs/
 *.sublime*
 .python-version
 .hatch
+.coverage*

pyproject.toml

@@ -81,6 +81,7 @@ dependencies = [
     "types-requests",
     "debugpy",
     "pydantic>=1.10.0, <2",
+    "pytest-cov",
 ]
 path = ".hatch"
 python = "3.9"
@@ -95,6 +96,7 @@ sqlw-e2e = "pytest --color=yes -v --profile databricks_uc_sql_endpoint -n auto -
 
 [tool.hatch.envs.test.scripts]
 unit = "pytest --color=yes -v --profile databricks_cluster -n auto --dist=loadscope tests/unit"
+unit-with-cov = "pytest --color=yes -v --profile databricks_cluster -n auto --dist=loadscope tests/unit --cov=dbt"
 
 [[tool.hatch.envs.test.matrix]]
 python = ["3.9", "3.10", "3.11", "3.12"]
@@ -132,3 +134,8 @@ disallow_untyped_defs = false
 [[tool.mypy.overrides]]
 module = ["databricks.*", "agate.*", "jinja2.*", "yaml.*"]
 ignore_missing_imports = true
+
+[tool.coverage.run]
+relative_files = true
+branch = true
+source = ["dbt"]