Switching modes don't trigger an auto reset prompt

[jeffreytse]

General information

Please report the following information as possible as you can:

• Terminal program: tmux 3.3a (screen-256color)
• Operating system: macOS 13.4.1 (22F770820d)
• ZSH framework: starship 1.15.0
• ZSH version: zsh 5.9 (x86_64-apple-darwin22.0)
• ZVM version: zsh-vi-mode 0.10.0 (1f28e18, 2023-07-26 18:28:07 +0800)

Basic examination

• I have read through the README page
• I have the latest version of zsh-vi-mode
• I have tested with another terminal program

Problem description

Switching modes doesn't trigger an auto reset prompt when users have a custom prompt string for mode indicator.

Reproduction steps

1. Change .zshrc file as below:

setopt prompt_subst
PROMPT='$(custom_prompt)'

custom_prompt() {
  if [[ $KEYMAP == "vicmd" ]]; then
    echo -n "vi cmd mode: "
  else
    echo -n "insert mode: "
  fi
}

source ~/zsh-vi-mode/zsh-vi-mode.zsh

2. Open terminal and enter zsh
3. Switch between INSERT and CMD modes via ESC and i
4. The prompt doesn't change between vicmd mode: and insert mode:

Expected behavior

The prompt should be auto changed as expectation.

[jeffreytse]

Related to #219