Add tests

example/draft-mlp/README.md

@@ -0,0 +1,4 @@
+# draft-mlp
+
+Example command that generates random MLP:CCG booster packs for a given set.
+This is mostly done to test the library itself.

set.go

@@ -10,15 +10,16 @@ type Set interface {
 // GenericSet is an generalized set of a card game
 // Treat this as an example implementation or a starting
 type GenericSet struct {
-	Cards    []Card
-	PackSize int
+	Cards      []Card
+	PackSize   int
+	Alternates []AlternateProvider
 }
 
 // PackSchema returns the pack schema from a booster containing all possible cards
 func (g *GenericSet) PackSchema() PackSchema {
 	return PackSchema{
 		Slots: []PackSlot{
-			{Amount: g.PackSize, Provider: g.RandomProvider()},
+			{Amount: g.PackSize, Provider: g.RandomProvider(), Alternate: g.Alternates},
 		},
 	}
 }

set_test.go

@@ -0,0 +1,136 @@
+package draft
+
+import (
+	"fmt"
+	"math/rand"
+	"testing"
+)
+
+// TestSetRepeatable makes sure that a set can generate more cards than it contains
+func TestSetRepeatable(t *testing.T) {
+	const PACKSIZE = 5
+	s := &GenericSet{
+		Cards:    []Card{{ID: "a"}, {ID: "b"}, {ID: "c"}},
+		PackSize: PACKSIZE,
+	}
+
+	// Create a pack
+	pack := MakePack(s)
+
+	if len(pack) < PACKSIZE {
+		t.Errorf("Pack expected to contain %d cards, contains %d", PACKSIZE, len(pack))
+	}
+
+	// Check that all cards have something in it
+	for i, card := range pack {
+		if card.ID == "" {
+			t.Errorf("Pack contains \"empty\" card")
+		}
+		if card.ID != "a" && card.ID != "b" && card.ID != "c" {
+			t.Errorf("Pack contains unexpected card %s at index %d, not contained in pool", card.ID, i)
+		}
+	}
+}
+
+// TestAlternateProviders tests alternate providers
+func TestAlternateProviders(t *testing.T) {
+	customProvider := func(n int) []Card {
+		out := make([]Card, n)
+		for n := range out {
+			out[n] = Card{ID: "x"}
+		}
+		return out
+	}
+	s := &GenericSet{
+		Cards:    []Card{{ID: "a"}, {ID: "b"}, {ID: "c"}},
+		PackSize: 1,
+		Alternates: []AlternateProvider{
+			{
+				Probability: 0.3,
+				Provider:    customProvider,
+			},
+		},
+	}
+	// Use set seed for getting deterministic results
+	rand.Seed(0)
+
+	nonalternates, alternates := 0, 0
+	for i := 0; i < 500000; i++ {
+		pack := MakePack(s)
+		if pack[0].ID == "x" {
+			alternates++
+		} else {
+			nonalternates++
+		}
+	}
+
+	// Calculate distribution
+	distribution := float32(float32(alternates) / (float32(nonalternates) + float32(alternates)))
+
+	// After 500k packs, I'm expecting distribution to be within 2%
+	if distribution < 0.29 || distribution > 0.31 {
+		t.Errorf("Distribution is sketchy after 500k packs: %f%%", distribution*100)
+	}
+}
+
+// TestCubeOverflow makes sure cubes stop providing cards as they are exhausted instead of going out of bound
+func TestCubeOverflow(t *testing.T) {
+	const PACKSIZE = 5
+	c := &GenericCube{
+		Cards: []Card{
+			{ID: "a"}, {ID: "b"}, {ID: "c"}, {ID: "d"}, {ID: "e"},
+			{ID: "f"}, {ID: "g"}, {ID: "h"}, {ID: "i"},
+		},
+		PackSize: PACKSIZE,
+	}
+
+	pack1 := MakePack(c)
+	pack2 := MakePack(c)
+
+	// Pack 2 can only contain 4 cards, as there are not enough cards to fill it
+	if len(pack2) >= PACKSIZE {
+		t.Errorf("Pack 2 expected to contain only 4 cards, has %d", len(pack2))
+	}
+
+	// Check for duplicates
+	allcards := append(pack1, pack2...)
+	uniq := sliceUniq(allcards)
+	if len(allcards) != len(uniq) {
+		t.Errorf("Duplicate cards found across packs")
+	}
+}
+
+// ExampleGenericSet is an example usage of the Set APIs to make packs
+func ExampleGenericSet() {
+	// Create a set with some items
+	s := &GenericSet{
+		Cards: []Card{
+			{ID: "a"},
+			{ID: "b"},
+			{ID: "c"},
+		},
+		PackSize: 5,
+	}
+
+	// Create a pack
+	pack := MakePack(s)
+
+	// Print cards in pack
+	for i, card := range pack {
+		fmt.Printf("Card #%d: %s\n", i, card.ID)
+	}
+}
+
+// https://gist.github.com/alioygur/16c66b4249cb42715091fe010eec7e33
+func sliceUniq(s []Card) []Card {
+	for i := 0; i < len(s); i++ {
+		for i2 := i + 1; i2 < len(s); i2++ {
+			if s[i].ID == s[i2].ID {
+				// delete
+				s = append(s[:i2], s[i2+1:]...)
+				i2--
+			}
+		}
+	}
+	return s
+}