Add NumberSchema and tests

app/src/main/java/hexlet/code/Validator.java

@@ -1,9 +1,13 @@
 package hexlet.code;
 
+import hexlet.code.schemas.NumberSchema;
 import hexlet.code.schemas.StringSchema;
 
 public class Validator {
     public StringSchema string() {
         return new StringSchema();
     }
+    public NumberSchema number() {
+        return new NumberSchema();
+    }
 }

app/src/main/java/hexlet/code/schemas/NumberSchema.java

@@ -0,0 +1,26 @@
+package hexlet.code.schemas;
+
+import lombok.NoArgsConstructor;
+import java.util.function.Predicate;
+
+@NoArgsConstructor
+public class NumberSchema extends BaseSchema<Integer> {
+    @Override
+    public NumberSchema required() {
+        Predicate<Integer> requiredFunction = ((value) -> value != null);
+        checkers.put("required", requiredFunction);
+        return this;
+    }
+
+    public NumberSchema positive() {
+        Predicate<Integer> positiveFunction = ((value) -> value > 0);
+        checkers.put("positive", positiveFunction);
+        return this;
+    }
+
+    public NumberSchema range(int startIndex, int finalIndex) {
+        Predicate<Integer> rangeFunction = ((value) -> value >= startIndex || value <= finalIndex);
+        checkers.put("range", rangeFunction);
+        return this;
+    }
+}

app/src/test/java/hexlet/code/ValidatorTest.java

@@ -1,5 +1,6 @@
 package hexlet.code;
 
+import hexlet.code.schemas.NumberSchema;
 import hexlet.code.schemas.StringSchema;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -9,10 +10,13 @@
 
 public class ValidatorTest {
     private static StringSchema stringSchema;
+    private static NumberSchema numberSchema;
     @BeforeEach
     public void preparation() {
         Validator val = new Validator();
         stringSchema = val.string();
+        Validator val1 = new Validator();
+        numberSchema = val1.number();
     }
 
     @Test
@@ -42,4 +46,29 @@ public void stringSchemaTestContains() {
         assertTrue(stringSchema.contains("hex").isValid("hexlet"));
         assertFalse(stringSchema.contains("hes").isValid("hexlet"));
     }
+
+    @Test
+    public void numberSchemaTestNormal() {
+        assertTrue(numberSchema.isValid(2));
+        assertTrue(numberSchema.isValid(null));
+    }
+
+    @Test
+    public void numberSchemaTestRequired() {
+        numberSchema.required();
+        assertFalse(numberSchema.isValid(null));
+    }
+
+    @Test
+    public void numberSchemaTestPositive() {
+        assertTrue(numberSchema.isValid(-10));
+        numberSchema.positive();
+        assertFalse(numberSchema.isValid(-10));
+    }
+
+    @Test
+    public void numberSchemaTestRange() {
+        numberSchema.range(5, 10);
+        assertTrue(numberSchema.isValid(10));
+    }
 }