TAP version 14
# ./main.js
not ok 1 - assert a b
  ---
  {"message":"AssertionError: Values are not equal.\n\n\n    [Diff] Actual / Expected\n\n\n-   foo\n+   bar\n\n","severity":"fail","at":{"file":"./main.js","line":1}}
  ...
1..1
error: Test failed