Closes#372
Fun YAML fact of the day:
What is the difference between how these two expressions are parsed?
```yaml
foo: >
bar
```
```yaml
foo: >-
bar
```
They are invisible in yaml, but when you evaluate them to JSON the
difference is obvious:
```json
{
"foo": "bar\n"
}
```
```json
{
"foo": "bar"
}
```
User-Agent strings, URL path values, and HTTP headers _do_ end in
newlines in HTTP/1.1 wire form, but that newline is usually stripped
before the server actually handles it. Also HTTP/2 is a thing and does
not terminate header values with newlines.
This change makes Anubis more aggressively detect mistaken uses of the
yaml `>` operator and nudges the user into using the yaml `>-` operator
which does not append the trailing newline.
I had honestly forgotten about this YAML behavior because it wasn't
relevant for so long. Oops! Glad I released a beta.
Whenever you get into this state, Anubis will throw a config parsing
error and then give you a message hinting at the folly of your ways.
```
config.Bot: regular expression ends with newline (try >- instead of > in yaml)
```
Big thanks to https://yaml-multiline.info, this helped me realize my
folly instantly.
@aiverson, this is official permission to say "told you so".
Signed-off-by: Xe Iaso <me@xeiaso.net>
This makes each check into its own type that has encapsulated check
logic, meaning that it's easier to add new checker implementations in
the future.
Signed-off-by: Xe Iaso <me@xeiaso.net>
