Jest expect.any() not working as expected - reactjs

Question

So when testing one of my reducers in a Preact(not much different to React while testing with JEST) based project, I got bumped into this issue:
Following output comes up when running jest test -
● should setup
expect(received).toEqual(expected)
Expected value to equal:
{"ID": Any<String>, "active": true, "data": Any<Array>}
Received:
{"ID": "BysnEuMlm", "active": true, "data": [{"ID": "Hy7wMAz1lm", "code": "dat.fle", "label": "CRES/datum14.cdata", "name": "File", "status": "READY", "value": {"format": "cdata", "name": "datum14.cdata", "path": "CRES"}}, {"ID": "rkB7RMkeX", "code": "prp.kcv", "label": "3 folds", "name": "k-Fold Cross-Validation", "status": "READY", "value": "3"}, {"ID": "ByCmRfygQ", "code": "ats", "label": undefined, "name": " Best First + Cfs Subset Eval", "status": "READY", "value": {"evaluator": {"name": "CfsSubsetEval"}, "search": {"name": "BestFirst", "options": ["-D", "1", "-N", "5"]}, "use": true}}, {"ID": "HkmVAM1l7", "code": "lrn", "label": undefined, "name": "Naive Bayes", "status": "READY", "value": {"label": "Naive Bayes", "name": "bayes.NaiveBayes", "use": true}}], "output": {"format": "pipeline", "name": "jestReact.cpipe", "path": "/home/rupav/opensource/candis/CRES"}}
Difference:
- Expected
+ Received
Object {
- "ID": Any<String>,
+ "ID": "BysnEuMlm",
"active": true,
- "data": Any<Array>,
+ "data": Array [
+ Object {
+ "ID": "Hy7wMAz1lm",
+ "code": "dat.fle",
+ "label": "CRES/datum14.cdata",
+ "name": "File",
+ "status": "READY",
+ "value": Object {
+ "format": "cdata",
+ "name": "datum14.cdata",
+ "path": "CRES",
+ },
+ },
+ Object {
+ "ID": "rkB7RMkeX",
+ "code": "prp.kcv",
+ "label": "3 folds",
+ "name": "k-Fold Cross-Validation",
+ "status": "READY",
+ "value": "3",
+ },
+ Object {
+ "ID": "ByCmRfygQ",
+ "code": "ats",
+ "label": undefined,
+ "name": " Best First + Cfs Subset Eval",
+ "status": "READY",
+ "value": Object {
+ "evaluator": Object {
+ "name": "CfsSubsetEval",
+ },
+ "search": Object {
+ "name": "BestFirst",
+ "options": Array [
+ "-D",
+ "1",
+ "-N",
+ "5",
+ ],
+ },
+ "use": true,
+ },
+ },
+ Object {
+ "ID": "HkmVAM1l7",
+ "code": "lrn",
+ "label": undefined,
+ "name": "Naive Bayes",
+ "status": "READY",
+ "value": Object {
+ "label": "Naive Bayes",
+ "name": "bayes.NaiveBayes",
+ "use": true,
+ },
+ },
+ ],
+ "output": Object {
+ "format": "pipeline",
+ "name": "jestReact.cpipe",
+ "path": "/home/rupav/opensource/candis/CRES",
+ },
}
Following is the test case:
test('should setup ', () => {
const state = documentProcessor(
undefined,
{
type: ActionType.Asynchronous.READ_SUCCESS,
payload: dokuments.active
})
// expect(state.active.ID).toEqual(expect.any(String)) - Test case passes iff I run this test with this command only.
expect(state.active).toEqual({
data: expect.any(Array),
active: true,
ID: expect.any(String),
})
})
Since state gets changed while calling that reducer, I needed to use expect.any function, but as per the output, although types are same, test is not getting passed.
Rather in expected its showing up Any<String>.

Answer 1

expect.toEqual checks for equality of state.active in your case. To achieve what you want, you have to make multiple expect statements:
expect(state.active.active).toEqual(true)
expect(state.active.data).toEqual(expect.any(Array))
expect(state.active.ID).toEqual(expect.any(String))

Answer 2

You can use toMatchObject:
expect(state.active).toMatchObject({
active: true,
data: expect.any(Array),
ID: expect.any(String)
});
See more examples in official documentation: https://jestjs.io/docs/en/expect#tomatchobjectobject