sic v2 client WP4: parseTarget — split host/hop1/hop2 into host + ordered hops

cmd/sic/addr.go

@@ -0,0 +1,30 @@
+package main
+
+func parseTarget(s string) (host string, hops []string) {
+	for i := 0; i < len(s); i++ {
+		if s[i] == '/' {
+			host = s[:i]
+			hops = splitHops(s[i+1:])
+			return
+		}
+	}
+	host = s
+	hops = nil
+	return
+}
+
+func splitHops(s string) []string {
+	if s == "" {
+		return nil
+	}
+	var hops []string
+	start := 0
+	for i := 0; i < len(s); i++ {
+		if s[i] == '/' {
+			hops = append(hops, s[start:i])
+			start = i + 1
+		}
+	}
+	hops = append(hops, s[start:])
+	return hops
+}

cmd/sic/parsetarget_test.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+// WP4: parseTarget splits "host/hop1/hop2" into the ssh host + the ordered nested hops. A bare
+// host (no '/') has no hops. Pure split; validation (empty host, hop count vs nest depth) is
+// resolveVerbs' job, not this one.
+func TestParseTarget(t *testing.T) {
+	cases := []struct {
+		in   string
+		host string
+		hops []string
+	}{
+		{"boltzmann", "boltzmann", nil},
+		{"boltzmann/memory", "boltzmann", []string{"memory"}},
+		{"boltzmann/memory/stash-stash-1", "boltzmann", []string{"memory", "stash-stash-1"}},
+	}
+	for _, tc := range cases {
+		host, hops := parseTarget(tc.in)
+		if host != tc.host || !reflect.DeepEqual(hops, tc.hops) {
+			t.Fatalf("parseTarget(%q) = (%q, %#v), want (%q, %#v)", tc.in, host, hops, tc.host, tc.hops)
+		}
+	}
+}