Add preview support (#16)

[danitrap]

Description

Adds preview functionality to sesh for displaying session/directory contents in fzf preview window, this should close #16 .

Features

• Add new preview command that supports either tmux sessions or directory listing
• Support for tmux session, config file and directory previews
• Add ls_command config option for customizing directory listing
• Expand fzf popup window size and add preview panel
• Update mocks with mockery v2.50.0

The preview shows:

• Active tmux session contents via capture-pane
• Directory listing for configured and zoxide paths
• Custom ls command support through config

Screenshots

Tmux Session

Config Directory

Tmuxinator

Zoxide

fd

custom preview_command with bat

[joshmedeski]

Dude, this is awesome, nice work!

Here is some feedback:

1. Can you provide some context for how the ls_command configuration works? I couldn't get it to work on my end
2. I'd prefer to rename ls_command to preview_command and allow any command to be passed (I'll use bat file in some cases)
3. Does the ls_command work for the default_session config as well?

Overall, this is great work, I don't see anything glaringly wrong with the code itself, just some clarification on the configuration, thanks again.

[danitrap]

Dude, this is awesome, nice work!

Thanks, my man @joshmedeski! I love using Sesh and wanted to contribute to give back. Thank you for creating it and for all your hard work.

1. Can you provide some context for how the ls_command configuration works? I couldn't get it to work on my end

Ah, I knew I was forgetting something—I didn’t document it, sorry about that! I’ll add documentation once we clarify its purpose and figure out how it should be configured.

In essence, ls_command lets you configure an alternative command for ls. For example, in my setup (shown in the screenshots in this PR), I’m using eza with this command:

$ eza --all --git --icons --color=always {path_to_directory}

This gives a nice ls output.

2. I'd prefer to rename ls_command to preview_command and allow any command to be passed (I'll use bat file in some cases)
3. Does the ls_command work for the default_session config as well?

I see how this might be confusing. Placing it in the default_session TOML table suggests it’s tied to new sessions or used for file previews.

In reality, it’s a directory previewer configuration. Perhaps we should create a dedicated TOML table for previewer-specific settings? Alternatively, we could move it to the root of the config for clarity. Let me know what you think!

Overall, this is great work, I don't see anything glaringly wrong with the code itself, just some clarification on the configuration, thanks again.

Thank you so much! This is actually my first contribution in Golang, so I’m thrilled it meets acceptable quality standards. I’m usually a TypeScript dev, so this was a fun learning experience.

[joshmedeski]

This is how I see the preview_command working:

[default_session]
startup_command = "nvim +GoToFile"
preview_command = "lsd  --group-dirs first -A {path_to_directory}"

[[session]]
name = "tmux config"
path = "~/c/dotfiles/.config/tmux"
startup_command = "nvim tmux.conf"
preview_command = "bat ~/c/dotfiles/.config/tmux/tmux.conf"

It's a preview for the session, so semantically I think it's clear for both default or custom sessions.

The only piece that isn't intuitive is the {path_to_directory} convention, but with clear instructions on the README and I think it will be okay.

---

Similar to the startup strategies, I recommend creating a default config strategy before the directory

		NewTmuxStrategy(lister, tmux),
		NewConfigStrategy(lister, ls),
                NewDefaultConfigStrategy(config, lister, ls), // config should be passed as a dependency to get the default value
		NewDirectoryStrategy(home, dir, ls),

[danitrap]

Oh, that makes sense! That's awesome, I'll work on it. Maybe we can borrow the syntax from fzf which uses {} as a placeholder for the currently selected item.

[danitrap]

Hey @joshmedeski,

I've added a custom preview_command to the per-session configuration and documented the previewer in the README. Let me know if you have any feedback.

Thank you!

[danitrap]

Hi @joshmedeski have you had a chance to look at this yet?

[joshmedeski]

Looks good to me, nice work!

[danitrap]

@joshmedeski thank you so much for merging it. Happy new year!