Oh-my-fish: FISH shell gives error test: Missing argument at index 2

[BrokenFlows]

Apologies if this is the wrong channel or for any other issues; I'm new to this.
I've tried to follow other solutions to this problem but haven't gotten anywhere.

At some point I got stuck with the error:
test: Missing argument at index 2

I uninstalled OMF, deleted ~/.config/omf/ and ~/.config/fish/.

I reinstalled and copied in a backup of ~/.config/fish/, it only really had a handful of functions to begin with as far as I know, and got errors because that fish_prompt assumed the pure theme. I reinstalled pure and then was back to getting the message test: Missing argument at index 2.

config.fish:
fish_vi_key_bindings

conf.d/omf.fish:
````

Path to Oh My Fish install.

set -q XDG_DATA_HOME
and set -gx OMF_PATH "$XDG_DATA_HOME/omf"
or set -gx OMF_PATH "$HOME/.local/share/omf"

Load Oh My Fish configuration.

source $OMF_PATH/init.fish
````

fish_prompt.fish (by pure):
````
function fish_prompt
set --local exit_code $status # save previous exit code

echo -e -n (_pure_prompt_beginning)  # init prompt context (clear current line, etc.)
echo -e (_pure_prompt_first_line)  # print current path, git branch/status, command duration
echo -e -n (_pure_prompt $exit_code)  # print prompt
echo -e (_pure_prompt_ending)  # reset colors and end prompt

set _pure_fresh_session false

end
````

Environment report

macOS 10.13.6
fish, version 2.7.1
Oh My Fish version 6
git version 2.14.2

omf doctor says:

```
Oh My Fish version: 6
OS type: Darwin
Fish version: fish, version 2.7.1
Git version: git version 2.14.2
Git core.autocrlf: no
Your shell is ready to swim.
test: Missing argument at index 2
test: Missing argument at index 2
test: Missing argument at index 2
~
[I]
````

[BrokenFlows]

Solved using commands from this section of the pure theme page. Not enough to just reinstall the theme.

omf install pure ln -s $OMF_PATH/themes/pure/conf.d/pure.fish ~/.config/fish/conf.d/pure.fish