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Jest Troubleshooting

Jest hangs after running tests​

You may have open handles preventing Jest from exiting cleanly. You can check it with --detectOpenHandles or force exit with --forceExit:

npx knapsack-pro-jest --detectOpenHandles

npx knapsack-pro-jest --forceExit

Also, make sure node has enough heap memory on your CI.

JavaScript heap out of memory​

You can increase the memory available to Node with --max_old_space_size:

export NODE_OPTIONS=--max_old_space_size=4096

npx knapsack-pro-jest

npx knapsack-pro-cypress

Debug Knapsack Pro on your development environment/machine​

To reproduce what Knapsack Pro executed on a specific CI node, check out the same branch and run:

KNAPSACK_PRO_TEST_SUITE_TOKEN_JEST=MY_TOKEN \
KNAPSACK_PRO_CI_NODE_INDEX=MY_INDEX \
KNAPSACK_PRO_CI_NODE_TOTAL=MY_TOTAL \
KNAPSACK_PRO_BRANCH=MY_BRANCH \
KNAPSACK_PRO_COMMIT_HASH=MY_COMMIT \
KNAPSACK_PRO_CI_NODE_BUILD_ID=MY_BUILD_ID \
KNAPSACK_PRO_FIXED_QUEUE_SPLIT=true \
KNAPSACK_PRO_TEST_FILE_PATTERN="{**/__tests__/**/*.js?(x),**/?(*.)(spec|test).js?(x)}" \
npx knapsack-pro-jest --runInBand

KNAPSACK_PRO_CI_NODE_BUILD_ID must be the same as the CI build you are trying to reproduce (if it helps, take a look at what Knapsack Pro uses as ciNodeBuildId for your CI provider).

No tests are executed (or test_files: [ 'parameter is required' ])​

Make sure KNAPSACK_PRO_TEST_FILE_PATTERN is correct.