Fix test assertions which were made weaker

In #968, which converted some specs to the new "expect" syntax, some assertions were incorrectly weakened from "eq" to "match_array". This pull request reverts them back to the stronger assertion (it doesn't make sense to assert without order in those examples).

Also, there were a couple of "let" blocks extracted for variables which are only used once, in a single spec each. This meant the test data was no longer near where it was used, which feels like a readability hit for no gain.