Fixed filter logic & added unit tests for filters.

The test helped my fix the filter problem. The problem was that I wasn't
cloning everything. Also, this is the first time I was actually able to
run the program! I have some TODOs now that the program finally runs:
- Remove input "3" from the help menu.
- Fix the new "Edit" bug and add a unit test for it.
- Writing to the file puts a bunch of new lines at the top. That's weird
  and should be fixed.

internal/deck/deck.go

@@ -67,6 +67,12 @@ func (d *Deck) FutureLen() int { return d.stack.FutureLen() }
 // Clones a deck into this deck.
 func (d *Deck) Clone(o *Deck) {
 	d.stack.Clone(o.stack)
+
+	d.cardMap = map[internal.Hash]*card.Card{}
+	for k, v := range o.cardMap {
+		d.cardMap[k] = v
+	}
+
 	d.cloneInfo(o)
 }
 

internal/deck/deck_test.go

@@ -20,19 +20,25 @@ func TestNewDeck(t *testing.T) {
 	assert.Len(t, d.PredictList(), 0)
 }
 
-func TestAddCardsTop(t *testing.T) {
+func TestAddCardsLen(t *testing.T) {
 	d := deck.NewDeck(ONE_DATE)
 	c1, _ := card.NewCards(".", "hi : yo")
 	d.AddCards(c1...)
 	assert.Len(t, d.CardList(), 2)
+}
+
+func TestAddCardsTop(t *testing.T) {
+	d := deck.NewDeck(ONE_DATE)
+	c1, _ := card.NewCards(".", "hi : yo")
+	d.AddCards(c1...)
 	assert.Equal(t, c1[0], d.TopCard())
 }
 
 func TestAddCardsPredictSameNext(t *testing.T) {
 	d := deck.NewDeck(ONE_DATE)
 	c1, _ := card.NewCards(".", "hi : yo")
 	d.AddCards(c1...)
-	p := meta.NewPredictFromStrings(c1[0].Hash().String(), "2020-01-01T00:00:00Z")
+	p := meta.NewPredictFromStrings(c1[0].Hash().String(), "0001-01-01T00:00:00Z")
 	d.AddPredicts(p)
 	assert.Equal(t, 2, d.ReviewLen())
 	assert.Equal(t, 0, d.FutureLen())
@@ -56,11 +62,38 @@ func TestPredictList(t *testing.T) {
 	assert.Equal(t, []meta.Predict{*p}, d.PredictList())
 }
 
-// TODO! Do this!
-func TestFilterMemorize(t *testing.T) {
-	d := deck.NewDeck(ONE_DATE)
-	h := internal.NewHash("fad")
-	p := meta.NewPredictFromStrings(h.String(), "2020-01-01T00:00:00Z")
-	d.AddPredicts(p)
-	assert.Equal(t, []meta.Predict{*p}, d.PredictList())
+func TestRemove(t *testing.T) {
+	h1 := internal.NewHash("73a6a403534bcc11b662e3a1d90d31e1")
+	h2 := internal.NewHash("abad2c2e5be5c33bc319ce038e3f2108")
+	cards, _ := card.NewCards(".", "hi : yo")
+
+	t.Run("Memorize", func(t *testing.T) {
+      d := deck.NewDeck(ONE_DATE)
+      d.AddCards(cards...)
+		d.AddPredicts(meta.NewPredictFromStrings(h1.String()), meta.NewPredictFromStrings(h2.String(), "", "", "1"))
+		d.RemoveMemorize()
+
+		assert.Equal(t, h2, *d.TopHash())
+		assert.Len(t, d.CardList(), 1)
+	})
+
+	t.Run("Review", func(t *testing.T) {
+      d := deck.NewDeck(ONE_DATE)
+      d.AddCards(cards...)
+		d.AddPredicts(meta.NewPredictFromStrings(h1.String()), meta.NewPredictFromStrings(h2.String(), "", "", "1"))
+		d.RemoveReview()
+
+		assert.Equal(t, h1, *d.TopHash())
+		assert.Len(t, d.CardList(), 1)
+	})
+
+	t.Run("Done", func(t *testing.T) {
+      d := deck.NewDeck(ONE_DATE)
+      d.AddCards(cards...)
+      d.AddPredicts(meta.NewPredictFromStrings(h1.String()), meta.NewPredictFromStrings(h2.String(), "2020-01-01T00:00:00Z", "", "1"))
+		d.RemoveDone()
+
+		assert.Equal(t, h1, *d.TopHash())
+		assert.Len(t, d.CardList(), 1)
+	})
 }

internal/deck/internal.go

@@ -11,7 +11,6 @@ import (
 type predicate func(int, internal.Hash) bool
 
 func (d *Deck) cloneInfo(o *Deck) {
-	d.stack.SetTime(o.stack.Time())
 	d.predictMap = map[internal.Hash]*meta.Predict{}
 	for k, v := range o.predictMap {
 		d.predictMap[k] = v
@@ -25,7 +24,7 @@ func (d *Deck) cloneInfo(o *Deck) {
 
 func (d *Deck) filter(p predicate) {
 	hashes := d.stack.List()
-	n := &Deck{}
+	n := NewDeck(d.stack.Time())
 	n.cloneInfo(d)
 
 	for i, h := range hashes {