Move MustParseDecimal function (#766)

lib/debezium/decimal.go

@@ -62,7 +62,7 @@ func decodeBigInt(data []byte) *big.Int {
 	return bigInt
 }
 
-// decimalWithNewExponent takes a [apd.Decimal] and returns a new [apd.Decimal] with a the given exponent.
+// decimalWithNewExponent takes a [*apd.Decimal] and returns a new [*apd.Decimal] with a the given exponent.
 // If the new exponent is less precise then the extra digits will be truncated.
 func decimalWithNewExponent(decimal *apd.Decimal, newExponent int32) *apd.Decimal {
 	exponentDelta := newExponent - decimal.Exponent // Exponent is negative.
@@ -89,7 +89,7 @@ func decimalWithNewExponent(decimal *apd.Decimal, newExponent int32) *apd.Decima
 	}
 }
 
-// EncodeDecimal is used to encode a [apd.Decimal] to [org.apache.kafka.connect.data.Decimal].
+// EncodeDecimal is used to encode a [*apd.Decimal] to [org.apache.kafka.connect.data.Decimal].
 // The scale of the value (which is the negated exponent of the decimal) is returned as the second argument.
 func EncodeDecimal(decimal *apd.Decimal) ([]byte, int32) {
 	bigIntValue := decimal.Coeff.MathBigInt()
@@ -100,7 +100,7 @@ func EncodeDecimal(decimal *apd.Decimal) ([]byte, int32) {
 	return encodeBigInt(bigIntValue), -decimal.Exponent
 }
 
-// EncodeDecimalWithScale is used to encode a [apd.Decimal] to [org.apache.kafka.connect.data.Decimal]
+// EncodeDecimalWithScale is used to encode a [*apd.Decimal] to [org.apache.kafka.connect.data.Decimal].
 // using a specific scale.
 func EncodeDecimalWithScale(decimal *apd.Decimal, scale int32) []byte {
 	targetExponent := -scale // Negate scale since [Decimal.Exponent] is negative.

lib/debezium/decimal_test.go

@@ -6,6 +6,7 @@ import (
 	"math/big"
 	"testing"
 
+	"github.com/artie-labs/transfer/lib/numbers"
 	"github.com/cockroachdb/apd/v3"
 	"github.com/stretchr/testify/assert"
 )
@@ -41,14 +42,6 @@ func TestDecodeBigInt(t *testing.T) {
 	}
 }
 
-func mustParseDecimal(value string) *apd.Decimal {
-	decimal, _, err := apd.NewFromString(value)
-	if err != nil {
-		panic(err)
-	}
-	return decimal
-}
-
 func TestDecimalWithNewExponent(t *testing.T) {
 	assert.Equal(t, "0", decimalWithNewExponent(apd.New(0, 0), 0).Text('f'))
 	assert.Equal(t, "00", decimalWithNewExponent(apd.New(0, 1), 1).Text('f'))
@@ -57,21 +50,21 @@ func TestDecimalWithNewExponent(t *testing.T) {
 	assert.Equal(t, "0.0", decimalWithNewExponent(apd.New(0, 0), -1).Text('f'))
 
 	// Same exponent:
-	assert.Equal(t, "12.349", decimalWithNewExponent(mustParseDecimal("12.349"), -3).Text('f'))
+	assert.Equal(t, "12.349", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), -3).Text('f'))
 	// More precise exponent:
-	assert.Equal(t, "12.3490", decimalWithNewExponent(mustParseDecimal("12.349"), -4).Text('f'))
-	assert.Equal(t, "12.34900", decimalWithNewExponent(mustParseDecimal("12.349"), -5).Text('f'))
+	assert.Equal(t, "12.3490", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), -4).Text('f'))
+	assert.Equal(t, "12.34900", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), -5).Text('f'))
 	// Lest precise exponent:
 	// Extra digits should be truncated rather than rounded.
-	assert.Equal(t, "12.34", decimalWithNewExponent(mustParseDecimal("12.349"), -2).Text('f'))
-	assert.Equal(t, "12.3", decimalWithNewExponent(mustParseDecimal("12.349"), -1).Text('f'))
-	assert.Equal(t, "12", decimalWithNewExponent(mustParseDecimal("12.349"), 0).Text('f'))
-	assert.Equal(t, "10", decimalWithNewExponent(mustParseDecimal("12.349"), 1).Text('f'))
+	assert.Equal(t, "12.34", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), -2).Text('f'))
+	assert.Equal(t, "12.3", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), -1).Text('f'))
+	assert.Equal(t, "12", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), 0).Text('f'))
+	assert.Equal(t, "10", decimalWithNewExponent(numbers.MustParseDecimal("12.349"), 1).Text('f'))
 }
 
 func TestEncodeDecimal(t *testing.T) {
 	testEncodeDecimal := func(value string, expectedScale int32) {
-		bytes, scale := EncodeDecimal(mustParseDecimal(value))
+		bytes, scale := EncodeDecimal(numbers.MustParseDecimal(value))
 		actual := DecodeDecimal(bytes, nil, int(scale)).String()
 		assert.Equal(t, value, actual, value)
 		assert.Equal(t, expectedScale, scale, value)
@@ -91,7 +84,7 @@ func TestEncodeDecimal(t *testing.T) {
 
 func TestEncodeDecimalWithScale(t *testing.T) {
 	mustEncodeAndDecodeDecimal := func(value string, scale int32) string {
-		bytes := EncodeDecimalWithScale(mustParseDecimal(value), scale)
+		bytes := EncodeDecimalWithScale(numbers.MustParseDecimal(value), scale)
 		return DecodeDecimal(bytes, nil, int(scale)).String()
 	}
 

lib/numbers/numbers.go

@@ -1,6 +1,17 @@
 package numbers
 
+import "github.com/cockroachdb/apd/v3"
+
 // BetweenEq - Looks something like this. start <= number <= end
 func BetweenEq[T int | int32 | int64](start, end, number T) bool {
 	return number >= start && number <= end
 }
+
+// MustParseDecimal parses a string to a [*apd.Decimal] or panics -- used for tests.
+func MustParseDecimal(value string) *apd.Decimal {
+	decimal, _, err := apd.NewFromString(value)
+	if err != nil {
+		panic(err)
+	}
+	return decimal
+}