add a test for the padding code

Author: whyrusleeping

ffiwrapper/ffiwrapper_test.go

@@ -0,0 +1,49 @@
+package ffiwrapper
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/ipfs/go-cid"
+)
+
+func TestZeroPadding(t *testing.T) {
+	psize := abi.PaddedPieceSize(128).Unpadded()
+	data := make([]byte, psize)
+
+	content := []byte("i am the biggest cat, what do you think about that")
+	copy(data, content)
+
+	pcid, err := GeneratePieceCIDFromFile(abi.RegisteredSealProof_StackedDrg32GiBV1_1, bytes.NewReader(data), psize)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// value calculated using separate tooling
+	expCid, err := cid.Decode("baga6ea4seaqozp3abki6vgdf7ztbipcycmxfyt2o64cpuyvdkczsjxsg7bqmioi")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if pcid != expCid {
+		t.Fatalf("expected %s, got %s", expCid, pcid)
+	}
+
+	padded, err := ZeroPadPieceCommitment(pcid, psize, psize*4)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	data2 := make([]byte, psize*4)
+	copy(data2, content)
+
+	padExpCid, err := GeneratePieceCIDFromFile(abi.RegisteredSealProof_StackedDrg32GiBV1_1, bytes.NewReader(data2), psize*4)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if padded != padExpCid {
+		t.Fatalf("wrong padding, expected %s, got %s", padExpCid, padded)
+	}
+}