Set a code coverage threshold with the Bun test runner

Bun’s test runner supports built-in code coverage reporting via the --coverage flag.

terminal

bun test --coverage

test.test.ts:
✓ math > add [0.71ms]
✓ math > multiply [0.03ms]
✓ random [0.13ms]
-------------|---------|---------|-------------------
File         | % Funcs | % Lines | Uncovered Line #s
-------------|---------|---------|-------------------
All files    |   66.67 |   77.78 |
 math.ts     |   50.00 |   66.67 |
 random.ts   |   50.00 |   66.67 |
-------------|---------|---------|-------------------

 3 pass
 0 fail
 3 expect() calls

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To set a minimum coverage threshold, add the following line to your bunfig.toml. This requires that 90% of your codebase is covered by tests.

bunfig.toml

[test]
# to require 90% line-level and function-level coverage
coverageThreshold = 0.9

---

If your test suite does not meet this threshold, bun test will exit with a non-zero exit code to signal a failure.

terminal

bun test --coverage

<test output>
$ echo $?
1 # this is the exit code of the previous command

---

Different thresholds can be set for line-level and function-level coverage.

bunfig.toml

[test]
# to set different thresholds for lines and functions
coverageThreshold = { lines = 0.5, functions = 0.7 }

---

See Docs > Test runner > Coverage for complete documentation on code coverage reporting in Bun.