I just pushed a commit that only modifies README.md, then Travis-CI reports the error about jest:
https://travis-ci.org/node-casbin/sequelize-adapter/jobs/489356290
I don’t know what it means. But it should not be the error of my code, or jest, because my code and jest are the same as previous successful build. So I doubt if Travis-CI has some kind of update or change that causes this error? Thanks.
A likely explanation is that something in your underlying dependencies changed and is causing the problem.
Try restarting a previously passing build (or tag a passing commit and push the tag). If it fails, I advise you to take a look at your dependencies.
I restarted a previously passing build and it resulted into the same error. What do you mean by underlying dependencies? In my understanding of NPM, all dependency versions are managed by package.json, right? So why would the dependency change if package.json remains the same? What kind of underlying dependencies should I check?
Often package managers allow certain degree of leeway when it comes to finding the versions of packages that, together, satisfy the requirement you specify in your file. Sometimes your configuration is not specific enough to prevent drift in versions used from one CI build to the next. Package managers may also offer a mechanism to “lock” the dependencies once they are resolved; e.g., https://docs.npmjs.com/files/package-lock.json
I don’t know enough about your code base to comment on that.
Please update typescript to 3.x