Chris, this is very helpful. I don't want to define my models (type Todo) in the same file as my jest global settings. Also, I have many test files where I need the same custom matcher. Can you describe the files used in a professional repo? What file contains declare global?
sorry for never responding on this topic, I seem to have forgotten about this notification. Nevertheless, I have since switched from Jest to Vitest, but the general process should be the same.
I have all my custom matchers in separate package in my monorepo, it's called lib-test and I install it in every other package that needs some test utilities like matchers or snapshot serializer. The matcher.ts file contains all custom matchers and defines the CustomMatchers interface. Here, I also add the interface to the Jest namespace (declare global { ...}) so it's available on the expect() functions.
One thing to note is, I don't use setupFilesAfterEnv in Jest config to automatically add the custom matchers. Instead, only in the test cases where I need the custom matcher, I import the toMatchTodo() from my lib-test and call expect.extend({ toMatchTodo }) at the beginning.
Because of this, the custom matcher is always available on the Jest namespace because in every test file that uses the custom matcher, the import from lib-test ensures the Jest namespace (declare global { ...}) was extended.
I hope this helps!
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
Chris, this is very helpful. I don't want to define my models (
type Todo) in the same file as my jest global settings. Also, I have many test files where I need the same custom matcher. Can you describe the files used in a professional repo? What file containsdeclare global?same question, any ideas @zirkelc ?
Hi @angelxmoreno and @cyrfer
sorry for never responding on this topic, I seem to have forgotten about this notification. Nevertheless, I have since switched from Jest to Vitest, but the general process should be the same.
I have all my custom matchers in separate package in my monorepo, it's called
lib-testand I install it in every other package that needs some test utilities like matchers or snapshot serializer. Thematcher.tsfile contains all custom matchers and defines theCustomMatchersinterface. Here, I also add the interface to the Jest namespace (declare global { ...}) so it's available on theexpect()functions.One thing to note is, I don't use
setupFilesAfterEnvin Jest config to automatically add the custom matchers. Instead, only in the test cases where I need the custom matcher, I import thetoMatchTodo()from mylib-testand callexpect.extend({ toMatchTodo })at the beginning.Because of this, the custom matcher is always available on the Jest namespace because in every test file that uses the custom matcher, the import from
lib-testensures the Jest namespace (declare global { ...}) was extended.I hope this helps!