feat: assert that yabai, skhd, choose are installed

README.md

@@ -1,7 +1,7 @@
 **unmarked 🎯**
 ---
 
-Similar to [`harpoon`](https://github.com/ThePrimeagen/harpoon), unmarked
+Similar to [`harpoon`](https://github.com/ThePrimeagen/harpoon/tree/harpoon2), unmarked
 is the keyboard user's tool for switching desktop windows using just their
 marks.
 

choosecmd.go

@@ -19,6 +19,10 @@ var chooseMarksCmd = &cobra.Command{
 	Short: "Choose from marked windows",
 	Long:  `Choose from all the marked windows`,
 	Run: func(_ *cobra.Command, _ []string) {
+		if !commandExists("choose") {
+			log.Fatalf("tool 'choose' is not installed. Install with 'brew install choose-gui'")
+		}
+
 		log.Printf("choosing marks under %v", stateHome)
 		chooseMarks()
 	},

init.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"os/exec"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func init() {
+	for _, tool := range []string{"ls", "yabai", "skhd"} {
+		log.Debugf("tool exists: %v -> %v", tool, commandExists(tool))
+		if !commandExists(tool) {
+			log.Fatalf("tool %v is not installed. Install with 'brew install %v'", tool, tool)
+		}
+	}
+}
+
+// as util
+func commandExists(cmd string) bool {
+	_, err := exec.LookPath(cmd)
+	return err == nil
+}