Running Coverage

Running the code coverage

Run every test suite in the workspace, picking the fastest compiled device backend for the host, then report the workspace code coverage.

Step 1: detect the device

Run this once at the start and echo the chosen device:

if [[ "$OSTYPE" == "darwin"* ]]; then
  DEVICE=metal
elif command -v nvidia-smi >/dev/null 2>&1 && nvidia-smi >/dev/null 2>&1; then
  DEVICE=cuda
else
  DEVICE=cpu
fi
echo "Device: $DEVICE"

$DEVICE selects the Rust integration suite variant in Step 2. The other four suites don't take a device feature.

Step 2: run the code coverage

Copy this checklist and tick each item as the suite completes:

TEST_DEVICE=$DEVICE make test.coverage

Step 3: rules during the run

• Serialize GPU suites. When $DEVICE is cuda or metal, run test suites sequentially to avoid device contention.
• Per-test 30 s budget. Flag any individual test that exceeds 30 s wall-clock. That is a real bug — production or test — not flakiness.

Step 4: report

After the coverage suite finishes, sum up the results in an actionable report.