refactor: Rewrote in golang.

app/features.go

@@ -0,0 +1,32 @@
+package app
+
+import (
+	"os/exec"
+)
+
+// Represents which binaries are present in $PATH.
+// Used to fail safely when required features are unavailable
+type AvailableFeatures int
+
+const (
+	Git AvailableFeatures = 1
+	// fd
+	Fd AvailableFeatures = 2
+	// All features are present
+	All AvailableFeatures = Git & Fd
+)
+
+// Checks for available features.
+func checkFeatures() (feats AvailableFeatures) {
+	// Check for git binary
+	if _, err := exec.LookPath("git"); err == nil {
+		feats |= Git
+	}
+
+	// Check for fd binary
+	if _, err := exec.LookPath("fd"); err == nil {
+		feats |= Fd
+	}
+
+	return feats
+}