jsontransformer: All numbers as numbers

Signed-off-by: kingthorin <kingthorin@users.noreply.github.com>

Author: kingthorin

src/main/java/net/datafaker/transformations/JsonTransformer.java

@@ -30,7 +30,7 @@ public String apply(IN input, Schema<IN, ?> schema) {
         StringBuilder sb = new StringBuilder();
         sb.append("{");
         for (int i = 0; i < fields.length; i++) {
-            value2String((fields[i].getName()), sb);
+            value2String(input, (fields[i].getName()), sb);
             sb.append(": ");
             if (fields[i] instanceof CompositeField) {
                 sb.append(apply(input, (CompositeField) fields[i], i));
@@ -94,7 +94,7 @@ private void applyValue(IN input, StringBuilder sb, Object value) {
         } else if (value != null && value.getClass().isArray()) {
             sb.append(generate(input, Arrays.asList((Object[]) value)));
         } else {
-            value2String(value, sb);
+            value2String(input, value, sb);
         }
     }
 
@@ -117,19 +117,18 @@ private String generate(IN input, Collection<Object> collection) {
         return sb.toString();
     }
 
-    private static void value2String(Object value, StringBuilder sb) {
+    private void value2String(IN input, Object value, StringBuilder sb) {
         if (value == null) {
             sb.append("null");
         } else if (value instanceof Integer
-            || value instanceof Long
-            || value instanceof Short
-            || value instanceof BigInteger
-            || value instanceof Boolean
-            || (value instanceof Double
-            && BigDecimal.valueOf((Double) value).remainder(BigDecimal.ONE).doubleValue() == 0)
-            || (value instanceof BigDecimal
-            && ((BigDecimal) value).remainder(BigDecimal.ONE).doubleValue() == 0)) {
-            sb.append(value);
+                || value instanceof Long
+                || value instanceof Short
+                || value instanceof BigInteger
+                || value instanceof Boolean
+                || value instanceof Double
+                || value instanceof BigDecimal) {
+            // Quote if input type is specifically String
+            sb = input instanceof String ? sb.append('"').append(value).append('"') : sb.append(value);
         } else {
             String val = String.valueOf(value);
             boolean toWrap = !val.startsWith("#{json");

src/test/java/net/datafaker/formats/JsonTest.java

@@ -204,7 +204,7 @@ private static Stream<Arguments> generateTestSchema() {
             of(Schema.of(field("key", () -> "value")), "{\"key\": \"value\"}"),
             of(Schema.of(field("number", () -> 123)), "{\"number\": 123}"),
             of(Schema.of(field("number", () -> 123.0)), "{\"number\": 123.0}"),
-            of(Schema.of(field("number", () -> 123.123)), "{\"number\": \"123.123\"}"),
+            of(Schema.of(field("number", () -> 123.123)), "{\"number\": 123.123}"),
             of(Schema.of(field("boolean", () -> true)), "{\"boolean\": true}"),
             of(Schema.of(field("nullValue", () -> null)), "{\"nullValue\": null}"),
             of(

src/test/java/net/datafaker/transformations/JsonTransformerTest.java

@@ -0,0 +1,39 @@
+package net.datafaker.transformations;
+
+import static net.datafaker.transformations.Field.field;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.math.BigDecimal;
+
+import org.junit.jupiter.api.Test;
+
+import net.datafaker.AbstractFakerTest;
+
+class JsonTransformerTest extends AbstractFakerTest{
+
+    @Test
+    void issue1556Double() {
+        // Given
+        double aDouble = faker.number().randomDouble(3, 1, 2);
+        Schema<Object, ?> schema = Schema.of(
+                field("Dbl", () -> aDouble));
+        // When
+        JsonTransformer<Object> transformer = JsonTransformer.builder().build();
+        String json = transformer.generate(schema, 1);
+        // Then - Number not quoted
+        assertThat(json).isEqualTo("{\"Dbl\": %s}".formatted(aDouble));
+    }
+
+    @Test
+    void issue1556BigDecimal() {
+        // Given
+        BigDecimal aBigDec = BigDecimal.valueOf(faker.number().randomDouble(7, 1, 2));
+        Schema<Object, ?> schema = Schema.of(
+                field("BigDecimal", () -> aBigDec));
+        // When
+        JsonTransformer<Object> transformer = JsonTransformer.builder().build();
+        String json = transformer.generate(schema, 1);
+        // Then - Number not quoted
+        assertThat(json).isEqualTo("{\"BigDecimal\": %s}".formatted(aBigDec));
+    }
+}