walk: handle map test separately

walk/walk_test.go

@@ -70,14 +70,6 @@ func TestWalk(t *testing.T) {
 			},
 			[]string{"London", "Paris"},
 		},
-		{
-			"maps",
-			map[string]string{
-				"Cow":   "meuh",
-				"Sheep": "meh",
-			},
-			[]string{"meuh", "meh"},
-		},
 	}
 
 	for _, test := range cases {
@@ -92,4 +84,32 @@ func TestWalk(t *testing.T) {
 			}
 		})
 	}
+
+	t.Run("with maps", func(t *testing.T) {
+		aMap := map[string]string{
+			"Cow":   "meuh",
+			"Sheep": "meh",
+		}
+		var got []string
+		Walk(aMap, func(input string) {
+			got = append(got, input)
+		})
+
+		assertContains(t, got, "meuh")
+		assertContains(t, got, "meh")
+	})
+}
+
+func assertContains(t testing.TB, haystack []string, needle string) {
+	t.Helper()
+	contains := false
+
+	for _, x := range haystack {
+		if x == needle {
+			contains = true
+		}
+	}
+	if !contains {
+		t.Errorf("expected %v to contain %q but it didn't", haystack, needle)
+	}
 }