⚙️ ci: add coverage check with margin tolerance

• 🛠️ Replace strict coverage --fail-under with custom script
• 📊 Use MIN_COVERAGE and MARGIN env vars for flexible thresholding
• 🚦 Fail only if coverage < (MIN_COVERAGE - COVERAGE_TOLERANCE_MARGIN), warn if within margin
• 🔧 Improve CI stability by allowing minor coverage fluctuations

Author: Falamarcao

.github/workflows/1_tests.yml

@@ -14,6 +14,7 @@ permissions: {}  # deny all by default
 env:
   UV_SYSTEM_PYTHON: 1
   MIN_COVERAGE: 70
+  COVERAGE_TOLERANCE_MARGIN: 5
 
 jobs:
   filter:
@@ -102,11 +103,7 @@ jobs:
         run: uv sync --locked --extra coverage
 
       - name: Combine and report coverage
-        run: |
-          uv run coverage combine
-          uv run coverage report --format=markdown >> $GITHUB_STEP_SUMMARY
-          uv run coverage report --fail-under=$MIN_COVERAGE
-
+        run: ./scripts/check_coverage.sh
   check:
     name: Did all tests pass?
     if: always()

scripts/check_coverage.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+MIN_COVERAGE="${MIN_COVERAGE:-70}"
+COVERAGE_TOLERANCE_MARGIN="${COVERAGE_TOLERANCE_MARGIN:-5}"
+
+# Combine coverage files if multiple exist
+if compgen -G ".coverage.*" > /dev/null; then
+  echo "🔄 Found multiple coverage files, combining..."
+  uv run coverage combine
+else
+  echo "ℹ️ No coverage files to combine."
+fi
+
+# Add markdown report to GitHub summary if available
+if [[ -n "${GITHUB_STEP_SUMMARY:-}" ]]; then
+  uv run coverage report --format=markdown >> "$GITHUB_STEP_SUMMARY"
+fi
+
+# Extract total coverage percentage (last column) - more robust
+COVERAGE_LINE=$(uv run coverage report | grep TOTAL || true)
+if [[ -z "$COVERAGE_LINE" ]]; then
+  echo "❌ Failed to extract coverage data"
+  exit 1
+fi
+
+COVERAGE=$(echo "$COVERAGE_LINE" | awk '{print $NF}' | tr -d '%' || echo "0")
+
+echo "📊 Reported coverage: ${COVERAGE}%"
+echo "🔢 Minimum required: ${MIN_COVERAGE}%"
+echo "➖ Tolerance margin: ${COVERAGE_TOLERANCE_MARGIN}%"
+
+if [[ -n "${GITHUB_STEP_SUMMARY:-}" ]]; then
+  {
+    echo "### 🧪 Coverage Check"
+    echo "- Total coverage: **${COVERAGE}%**"
+    echo "- Minimum required: **${MIN_COVERAGE}%**"
+    echo "- Allowed margin: **${COVERAGE_TOLERANCE_MARGIN}%**"
+  } >> "$GITHUB_STEP_SUMMARY"
+fi
+
+# Check coverage against threshold with margin
+if (( $(echo "$COVERAGE < $MIN_COVERAGE - $COVERAGE_TOLERANCE_MARGIN" | bc -l) )); then
+  echo "❌ Coverage ${COVERAGE}% is below allowed margin. Failing..."
+  exit 1
+elif (( $(echo "$COVERAGE < $MIN_COVERAGE" | bc -l) )); then
+  echo "⚠️ Coverage ${COVERAGE}% is below threshold but within margin."
+else
+  echo "✅ Coverage ${COVERAGE}% meets the threshold."
+fi
+
+# Clean up coverage files after reporting
+rm -f .coverage.* .coverage