Exit on MongoDB connection error

[radekmie]

As suggested by @zodern in https://github.com/meteor/meteor/pull/12097#issuecomment-1199782349, the app should fail on MongoDB connection error. In this PR I added such a check (as well as a test for it).

[Grubba27]

The failed tests do not seem to be related to the PR. I would change the test a little to make it work, but I'm not sure if it is the right move:

    const sourceMap = e.stack.split(":")[index];
    const r = (sourceMap === "17" || sourceMap === "18");
    selftest.expectEqual(r, true);

in tools/tests/source-maps.js

[radekmie]

@Grubba27 After a rebase it fails with the same errors like https://github.com/meteor/meteor/pull/12116#issuecomment-1214069103.

[fredmaiaarantes]

The failed tests do not seem to be related to the PR. I would change the test a little to make it work, but I'm not sure if it is the right move:

    const sourceMap = e.stack.split(":")[index];
    const r = (sourceMap === "17" || sourceMap === "18");
    selftest.expectEqual(r, true);

in tools/tests/source-maps.js

The flaky test we fixed was not the one failing here @Grubba27. It was failing on this PR (https://github.com/meteor/meteor/pull/12125), and it was related to the source-maps tests. Now we need to look into these other ones.