bpi growth is also just compounding interest but ignore for now

ledger/predict_test.go

@@ -1,14 +1,16 @@
 package ledger
 
 import (
+	"slices"
 	"testing"
+	"time"
 )
 
 func TestRegisterPrediction(t *testing.T) {
 	t.Run("contribution", func(t *testing.T) {
 		input := newTestRegister()
 
-		got, err := RegisterWithContributionPrediction(input, .12)
+		got, err := RegisterWithContributionPrediction(input, time.Hour*24*365)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -26,7 +28,7 @@ func TestRegisterPrediction(t *testing.T) {
 	t.Run("compounding interest", func(t *testing.T) {
 		input := newTestRegister()
 
-		got, err := RegisterWithCompoundingInterestPrediction(input, 1, "X", .04)
+		got, err := RegisterWithCompoundingInterestPrediction(input, time.Hour*24*365, "X", .04)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -35,13 +37,38 @@ func TestRegisterPrediction(t *testing.T) {
 		if len(got) <= len(input) {
 			t.Error(len(got))
 		}
-		t.Error("not impl")
+
+		for _, date := range got.Dates() {
+			for name, balance := range got[date] {
+				t.Logf("%s | %s %s", date, name, balance.Debug())
+			}
+		}
 	})
 }
 
 func TestBPIPrediction(t *testing.T) {
 	t.Run("fixed growth", func(t *testing.T) {
-		t.Error("not impl")
+		bpis := BPIs{
+			USD: BPI{
+				"2001-01": -1000,
+				"2001-02": 100,
+			},
+		}
+
+		got, err := BPIsWithFixedGrowthPrediction(bpis, time.Hour*24*365, string(USD), 0.06)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		dates := []string{}
+		for d := range got[USD] {
+			dates = append(dates, d)
+		}
+		slices.Sort(dates)
+
+		for _, d := range dates {
+			t.Logf("%s | %s %.2f", USD, d, got[USD][d])
+		}
 	})
 }