CHANGELOG.md

@@ -1,3 +1,7 @@
+# 1.14.2 (February 5, 2024)
+
+* Fix numeric to float64 conversion (Joe Schafer)
+
 # 1.14.1 (January 12, 2024)
 
 * Backport fix numeric to string conversion for small negative values

numeric.go

@@ -448,7 +448,7 @@ func (src *Numeric) toFloat64() (float64, error) {
 		return math.Inf(-1), nil
 	}
 
-	if src.Exp == 1 {
+	if src.Exp == 0 {
 		return float64(src.Int.Int64()), nil
 	}
 

numeric_test.go

@@ -385,6 +385,7 @@ func TestNumericEncodeDecodeBinary(t *testing.T) {
 		123,
 		0.000012345,
 		1.00002345,
+		50.000000,
 		math.NaN(),
 		float32(math.NaN()),
 		math.Inf(1),
@@ -442,3 +443,28 @@ func TestNumericSmallNegativeValues(t *testing.T) {
 		t.Fatalf("expected %s, got %s", "-0.000123", s)
 	}
 }
+
+// https://github.com/jackc/pgtype/issues/210
+func TestNumericFloat64Exhaustive(t *testing.T) {
+	for exp := -10; exp <= 10; exp++ {
+		for i := -100; i < 100; i++ {
+			n := pgtype.Numeric{
+				Int:    big.NewInt(int64(i)),
+				Exp:    int32(exp),
+				Status: pgtype.Present,
+			}
+
+			var got float64
+			err := n.AssignTo(&got)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			want := float64(i) * math.Pow10(exp)
+			delta := math.Abs(want * 0.0000000001)
+			if math.Abs(got-want) > delta {
+				t.Fatalf("expected %f from %de%d, got %f", want, i, exp, got)
+			}
+		}
+	}
+}