Xcode 10.2 | NSInvalidArgumentException

[mylegfeelsfunny]

Xcode 10.2
Mojave 10.14.3
Swift 4.2

Scenario

When we run the tests, it appears there are scenarios where the strings cannot bridge between objectiveC and swift. Its somehow seems to be related to the content.

NSInvalidArgumentException -[Swift.__SharedStringStorage stringValue]: unrecognized 
selector sent to instance 0x60000203d3e0

Could it be Apple?

Example:

If the output is The Under $5 Rule for expectationThe Under $5 Rule, the test should pass but we get the exception.

If the output is The Under $5 Ru for expectation The Under $5 Ru, the test passes.

If the output is The Under $5 Ru for expectation The Under $5 Rule, the test fails but as it should.