add number test where num starts with a dot (#4436)

src/test/java/com/fasterxml/jackson/databind/deser/TestBigNumbers.java

@@ -13,32 +13,12 @@
 
 public class TestBigNumbers extends BaseMapTest
 {
-    static class BigDecimalWrapper {
-        BigDecimal number;
-
-        public BigDecimalWrapper() {}
-
-        public BigDecimalWrapper(BigDecimal number) {
-            this.number = number;
-        }
-
-        public void setNumber(BigDecimal number) {
-            this.number = number;
-        }
-    }
-
     static class BigIntegerWrapper {
-        BigInteger number;
-
-        public BigIntegerWrapper() {}
-
-        public BigIntegerWrapper(BigInteger number) {
-            this.number = number;
-        }
+        public BigInteger number;
+    }
 
-        public void setNumber(BigInteger number) {
-            this.number = number;
-        }
+    static class BigDecimalWrapper {
+        public BigDecimal number;
     }
 
     /*

src/test/java/com/fasterxml/jackson/databind/deser/jdk/BigDecimalDeser4435Test.java

@@ -0,0 +1,49 @@
+package com.fasterxml.jackson.databind.deser.jdk;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import org.junit.jupiter.api.Test;
+
+import java.math.BigDecimal;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+// @since 2.16.3
+public class BigDecimalDeser4435Test
+{
+    static class BigDecimalWrapper {
+        public BigDecimal number;
+    }
+
+    /*
+    /**********************************************************
+    /* Tests
+    /**********************************************************
+     */
+
+    private final ObjectMapper MAPPER = JsonMapper.builder().build();
+
+    @Test
+    public void testNumberStartingWithDot() throws Exception
+    {
+        String num = ".555555555555555555555555555555";
+        BigDecimalWrapper w = MAPPER.readValue("{\"number\":\"" + num + "\"}", BigDecimalWrapper.class);
+        assertEquals(new BigDecimal(num), w.number);
+    }
+
+    @Test
+    public void testNumberStartingWithMinusDot() throws Exception
+    {
+        String num = "-.555555555555555555555555555555";
+        BigDecimalWrapper w = MAPPER.readValue("{\"number\":\"" + num + "\"}", BigDecimalWrapper.class);
+        assertEquals(new BigDecimal(num), w.number);
+    }
+
+    @Test
+    public void testNumberStartingWithPlusDot() throws Exception
+    {
+        String num = "+.555555555555555555555555555555";
+        BigDecimalWrapper w = MAPPER.readValue("{\"number\":\"" + num + "\"}", BigDecimalWrapper.class);
+        assertEquals(new BigDecimal(num), w.number);
+    }
+}