add hashCode generation

Author: MrMaydo

src/method_generator.py

@@ -106,6 +106,26 @@ def generate_setter(field: Field) -> str:
     return setter
 
 
+def generate_hash_code(fields: List[Field]) -> str:
+    hash_code = [
+        "",
+        f"{indent_lvl1}@Override",
+        f"{indent_lvl1}public int hashCode() {{",
+        f"{indent_lvl2}return Objects.hash("
+    ]
+
+    for i, field in enumerate(fields):
+        _validate_java_identifier(field.name)
+        getter_name = "get" + field.name[0].upper() + field.name[1:]
+        comma = "," if i < (len(fields) - 1) else ""
+        hash_code.append(f"{indent_lvl2}        {getter_name}(){comma}")
+
+    hash_code.append(f"{indent_lvl2});")
+    hash_code.append(f"{indent_lvl1}}}")
+
+    return "\n".join(hash_code)
+
+
 def _validate_java_identifier(name: str) -> None:
     if not name:
         raise ValueError("Field name cannot be empty")

tests/test_method_generator.py

@@ -136,3 +136,27 @@ def test_generate_fields_block():
      */
     private CustomObject customData;"""
     assert generate_fields_block(attributes) == expected
+
+
+def test_generate_hash_code():
+    attr1 = field_exampleAttribute_int
+    attr2 = field_someName_String
+    attr3 = field_customData_CustomObject
+    attributes = [attr1, attr2, attr3]
+    expected = """
+    @Override
+    public int hashCode() {
+        return Objects.hash(
+                getExampleAttribute(),
+                getSomeName(),
+                getCustomData()
+        );
+    }"""
+    assert generate_hash_code(attributes) == expected
+
+
+def test_generate_hash_code_invalid_name():
+    for name in illegal_names:
+        attr = Field(name=name, type="String")
+        with pytest.raises(ValueError):
+            generate_hash_code([attr])