Replace DecodeV2 with ExtractEncoding

cid-fmt/main.go

@@ -69,15 +69,16 @@ outer:
 		}
 	}
 	for _, cidStr := range args[1:] {
-		base, cid, err := c.DecodeV2(cidStr)
+		cid, err := c.Decode(cidStr)
 		if err != nil {
 			fmt.Fprintf(os.Stdout, "!INVALID_CID!\n")
 			errorMsg("%s: %v", cidStr, err)
 			// Don't abort on a bad cid
 			continue
 		}
-		if newBase != -1 {
-			base = newBase
+		base := newBase
+		if newBase == -1 {
+			base, _ = c.ExtractEncoding(cidStr)
 		}
 		if verConv != nil {
 			cid, err = verConv(cid)

cid-fmt/main_test.go

@@ -10,7 +10,7 @@ import (
 func TestCidConv(t *testing.T) {
 	cidv0 := "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"
 	cidv1 := "zdj7WbTaiJT1fgatdet9Ei9iDB5hdCxkbVyhyh8YTUnXMiwYi"
-	_, cid, err := c.DecodeV2(cidv0)
+	cid, err := c.Decode(cidv0)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -34,7 +34,7 @@ func TestCidConv(t *testing.T) {
 func TestBadCidConv(t *testing.T) {
 	// this cid is a raw leaf and should not be able to convert to cidv0
 	cidv1 := "zb2rhhzX7uSKrtQ2ZZXFAabKiKFYZrJqKY2KE1cJ8yre2GSWZ"
-	_, cid, err := c.DecodeV2(cidv1)
+	cid, err := c.Decode(cidv1)
 	if err != nil {
 		t.Fatal(err)
 	}

format_test.go

@@ -55,13 +55,14 @@ func TestFmt(t *testing.T) {
 }
 
 func testFmt(t *testing.T, cidStr string, newBase mb.Encoding, fmtStr string, result string) {
-	base, cid, err := DecodeV2(cidStr)
-	if newBase != -1 {
-		base = newBase
-	}
+	cid, err := Decode(cidStr)
 	if err != nil {
 		t.Fatal(err)
 	}
+	base := newBase
+	if newBase == -1 {
+		base, _ = ExtractEncoding(cidStr)
+	}
 	str, err := Format(fmtStr, base, cid)
 	if err != nil {
 		t.Fatal(err)
@@ -70,4 +71,3 @@ func testFmt(t *testing.T, cidStr string, newBase mb.Encoding, fmtStr string, re
 		t.Error(fmt.Sprintf("expected: %s; but got: %s", result, str))
 	}
 }
-