feat(npm): toggle `npm install` / `npm uninstall` by pressing F2 twice (#9717)

Co-authored-by: Marc Cornellà <hello@mcornella.com>

plugins/npm/README.md

@@ -29,3 +29,20 @@ plugins=(... npm)
 | `npmI`  | `npm init`                   | Run npm init                                                    |
 | `npmi`  | `npm info`                   | Run npm info                                                    |
 | `npmSe` | `npm search`                 | Run npm search                                                  |
+
+## `npm install` / `npm uninstall` toggle
+
+The plugin adds a function that toggles between `npm install` and `npm uninstall` in
+the current command or the last command, for up to 2 previous commands. **The default
+key binding is pressing <kbd>F2</kbd> twice**.
+
+You can change this key binding by adding the following line to your zshrc file:
+
+```zsh
+bindkey -M emacs '<seq>' npm_toggle_install_uninstall
+bindkey -M vicmd '<seq>' npm_toggle_install_uninstall
+bindkey -M viins '<seq>' npm_toggle_install_uninstall
+```
+
+where `<seq>` is a key sequence obtained by running `cat` and pressing the keyboard
+sequence you want.

plugins/npm/npm.plugin.zsh

@@ -69,3 +69,43 @@ alias npmi="npm info"
 
 # Run npm search
 alias npmSe="npm search"
+
+npm_toggle_install_uninstall() {
+  # Look up to the previous 2 history commands
+  local line
+  for line in "$BUFFER" \
+    "${history[$((HISTCMD-1))]}" \
+    "${history[$((HISTCMD-2))]}"
+  do
+    case "$line" in
+      "npm uninstall"*)
+        BUFFER="${line/npm uninstall/npm install}"
+        (( CURSOR = CURSOR + 2 )) # uninstall -> install: 2 chars removed
+        ;;
+      "npm install"*)
+        BUFFER="${line/npm install/npm uninstall}"
+        (( CURSOR = CURSOR + 2 )) # install -> uninstall: 2 chars added
+        ;;
+      "npm un "*)
+        BUFFER="${line/npm un/npm install}"
+        (( CURSOR = CURSOR + 5 )) # un -> install: 5 chars added
+        ;;
+      "npm i "*)
+        BUFFER="${line/npm i/npm uninstall}"
+        (( CURSOR = CURSOR + 8 )) # i -> uninstall: 8 chars added
+        ;;
+      *) continue ;;
+    esac
+    return 0
+  done
+
+  BUFFER="npm install"
+  CURSOR=${#BUFFER}
+}
+
+zle -N npm_toggle_install_uninstall
+
+# Defined shortcut keys: [F2] [F2]
+bindkey -M emacs '^[OQ^[OQ' npm_toggle_install_uninstall
+bindkey -M vicmd '^[OQ^[OQ' npm_toggle_install_uninstall
+bindkey -M viins '^[OQ^[OQ' npm_toggle_install_uninstall