Add a test for derive_builder crate

Author: qryxip

tests/derive_builder.rs

@@ -0,0 +1,22 @@
+use derive_builder::Builder;
+
+#[test]
+fn builder() {
+    #[derive(Builder, Debug, PartialEq)]
+    struct Person {
+        name: Option<String>,
+        age: Option<u32>,
+    }
+
+    assert_eq!(
+        PersonBuilder::default()
+            .name(Some("John".to_owned()))
+            .age(Some(20))
+            .build()
+            .unwrap(),
+        Person {
+            name: Some("John".to_owned()),
+            age: Some(20),
+        },
+    );
+}