Better error handling for sendFile

[thevoidf]

so you don't get confusing errors like: function substring not found or something

[dougwilson]

Nice! Can you add a test that tests the condition in which you were encountering? That way we don't accidentally regress.

[dougwilson]

Also, can you add back res.sendFile to the message? Helps people know what function the issue was to.

[thevoidf]

if you pass something other than valid string like sendFile({}) you get: TypeError: path.substring is not a function. which is kind of confusing, so instead now you getting: path must be string

[dougwilson]

Makes sense. Just add a test for that so we have it there to not regress from a refactor 👍

[thevoidf]

@dougwilson all test are passing on my system

[LinusU]

The build failures seemed unrelated, I restarted the two failed builds...