javascript

Vitest mock returns wrong type

vitest.*TypeError.*is not a function.*mock

Fixes

1.Use vi.fn().mockReturnValue() correctly
2.Return correct type from mock factory
3.Check auto-mock generated correct shape

vitestmocktype

Related Errors

javascript3 fixes

Cannot read property of undefined

Cannot read propert(y|ies) of undefined

•Add optional chaining (?.)
•Check if object exists before accessing

javascript3 fixes

Cannot read property of null

Cannot read propert(y|ies) of null

•Add null check before access
•Use optional chaining (?.)

javascript3 fixes

TypeError: X is not a function

is not a function

•Check spelling of method name
•Verify import is correct