Made encode/decode api more symmetric. Added some unit test for the encoders/decoders.

common/coords_test.go

@@ -2,11 +2,10 @@ package common
 
 import "testing"
 
-//var data = []int16{-2}
 var data = []int16{
 	-2045, -1850, -1811, -1629, -1104,
 	-967, -725, -646, -329, -212,
-	-150, 88, 524, 527, 549,
+	-150, -1, 0, 1, 88, 524, 527, 549,
 	1783, 1817, 1826, 2028, 2032}
 
 func allData(f func(int16, int16, int16)) {
@@ -19,6 +18,50 @@ func allData(f func(int16, int16, int16)) {
 	}
 }
 
+func checkEncodeDecode(
+	desc string,
+	join KeyJoiner,
+	encode KeyEncoder, decode KeyDecoder,
+	x, y, z int16, t *testing.T) {
+
+	k1 := join(x, y, z)
+	var err error
+	var b []byte
+	if b, err = encode(k1); err != nil {
+		t.Errorf("%s: Failed to encode (%d, %d, %d) %s\n",
+			desc, x, y, z, err)
+		return
+	}
+	var k2 int64
+	if k2, err = decode(b); err != nil {
+		t.Errorf("%s: Failed to decode (%d, %d, %d) %s\n",
+			desc, x, y, z, err)
+		return
+	}
+
+	if k1 != k2 {
+		t.Errorf("%s: Expected %d got %d for (%d, %d, %d) %b\n",
+			desc, k1, k2, x, y, z)
+	}
+}
+
+func TestEncodeDecode(t *testing.T) {
+	allData(func(x, y, z int16) {
+		checkEncodeDecode(
+			"Big endian",
+			XYZToInterleaved,
+			EncodeToBigEndian, DecodeFromBigEndian,
+			x, y, z, t)
+	})
+	allData(func(x, y, z int16) {
+		checkEncodeDecode(
+			"String",
+			XYZToInterleaved,
+			EncodeStringToBytes, DecodeStringFromBytes,
+			x, y, z, t)
+	})
+}
+
 func checkJoinSplit(
 	desc string,
 	join KeyJoiner, split KeySplitter,