feat: wider fuzz tests, stronger options. (#9)

- Added all `Option`-s to the fuzz tests.
  - Minimum load is always <=20%.
- Tested all options, and force a panic on all invalid options.
  - Capacity must now be non-negative.
  - Minimum load should be <=20%, but just put it as a recommendation.

Reviewed-on: #9
Co-authored-by: M.V. Hutz <git@maximhutz.me>
Co-committed-by: M.V. Hutz <git@maximhutz.me>

settings.go

@@ -1,5 +1,7 @@
 package cuckoo
 
+import "fmt"
+
 // DefaultCapacity is the initial capacity of a [Table]. It is inspired from
 // Java's [HashMap] implementation, which also uses 16.
 //
@@ -27,19 +29,34 @@ type settings struct {
 type Option func(*settings)
 
 // Capacity modifies the starting capacity of each bucket of the [Table]. The
-// value must be greater than 0.
+// value must be non-negative.
 func Capacity(value int) Option {
+	if value < 0 {
+		panic(fmt.Sprintf("go-cuckoo: Capacity must be non-negative, got %d", value))
+	}
+
 	return func(s *settings) { s.bucketSize = uint64(value) }
 }
 
 // MinimumLoad modifies the [DefaultMinimumLoad] of the [Table]. The value must
 // be between 0.00 and 1.00.
+//
+// The higher the minimum load, the more likely that a [Table.Put] will not
+// succeed. Minimum loads above 20% are not tested.
 func MinimumLoad(value float64) Option {
+	if value < 0.00 || value > 1.00 {
+		panic(fmt.Sprintf("go-cuckoo: MinimumLoad must be between 0.00 and 1.00, got %f", value))
+	}
+
 	return func(s *settings) { s.minLoadFactor = value }
 }
 
 // GrowthFactor controls how much the capacity of the [Table] multiplies when
 // it must resize. The value must be greater than 1.
 func GrowthFactor(value int) Option {
+	if value < 2 {
+		panic(fmt.Sprintf("go-cuckoo: GrowthFactor must be greater than 1, got %d", value))
+	}
+
 	return func(s *settings) { s.growthFactor = uint64(value) }
 }