To enable tab completion, run the following command: 
hop completions  <shell> > /some/path/to/hop-completion
where <shell> is one of bash, zsh or fish.
If you get permission denied error, you can try running the following command:
# pipe output to sudo tee and do not output to the tty
$ hop completions <shell> | sudo tee /some/path/to/hop-completion > /dev/null
The commands above will output the completion script to the specified path. Which will look something like this: 
$ hop completions zsh
#compdef hop

autoload -U is-at-least

_hop() {
    typeset -A opt_args
    typeset -a _arguments_options
    local ret=1

...

_hop "$@"
The correct method of installing a completion script can depend on both your shell and your configuration.

​
Installation

Completions typically will be installed automatically by your shell’s package manager and the script will try to install them.

​
Zsh

This example shows how to enable tab completion for zsh, it assumes you are using oh-my-zsh. 
$ hop completions zsh > ~/.oh-my-zsh/completions/_hop
Your completion script must have the name in the format of _ followed by the name of the application.
Without oh-my-zsh, you will need to add a path for completion scripts to your function path, and turn on completion script autoloading. First, add these lines to ~/.zshrc: 
fpath=(~/.zsh/completion $fpath)
autoload -U compinit
compinit
Next, create a directory at ~/.zsh/completion and copy the completion script to the new directory.

​
Bash

If you have bash-completion installed, you can just copy your new completion script to the /usr/local/etc/bash_completion.d or /usr/share/bash-completion/completions directory using the following command: 
$ hop completions bash > /usr/local/etc/bash_completion.d/hop
Without bash-completion, you will need to source the completion script directly. Copy it to a directory such as ~/.bash_completions/, and then add the following line to ~/.bash_profile or ~/.bashrc: 
$ source ~/.bash_completions/hop

​
Fish

To enable tab completion for fish, copy the completion script to the ~/.config/fish/completions or /usr/share/fish/completions directory using the following command: 
$ hop completions fish > ~/.config/fish/completions/hop.fish