In my case, I was getting this error when I serve the app, not when testing. I didn't realise I had a different configuration setting in my tsconfig.app.json file.
I previously had this:
{
...
"include": [
"src/**/*.ts"
]
}
It was including all my .spec.ts files when serving the app. I changed the include property toexclude` and added a regex to exclude all test files like this:
{
...
"exclude": [
"**/*.spec.ts",
"**/__mocks__"
]
}
Now it works as expected.