add: write_json_tests

src/bin/tests/mod.rs

@@ -1 +1,2 @@
 mod read_json_test;
+mod write_json_tests;

src/bin/tests/write_json_tests.rs

@@ -0,0 +1,47 @@
+#[cfg(test)]
+mod write_json_tests {
+    use serde::{Deserialize, Serialize};
+    use serde_json::json;
+    use std::collections::HashMap;
+
+    #[derive(Serialize, Deserialize)]
+    struct A<'a> {
+        a: &'a str,
+        b: &'a str,
+    }
+    #[derive(Serialize, Deserialize)]
+    struct B<'z> {
+        x: &'z str,
+        y: [A<'z>; 2],
+    }
+
+    #[test]
+    fn it_writes_json_from_hashmap() {
+        let mut map = HashMap::new();
+        map.insert("name", "John");
+        map.insert("age", "30");
+        map.insert("city", "New York");
+
+        let json = json!(map);
+        assert_eq!(
+            json.to_string(),
+            r#"{"age":"30","city":"New York","name":"John"}"#
+        );
+    }
+
+    #[test]
+    fn it_writes_json() {
+        let json_to_serialize = B {
+            x: "x",
+            y: [A { a: "x", b: "y" }, A { a: "p", b: "q" }],
+        };
+        let serialized_json = serde_json::to_string(&json_to_serialize);
+        match serialized_json {
+            Ok(json) => assert_eq!(
+                json,
+                r#"{"x":"x","y":[{"a":"x","b":"y"},{"a":"p","b":"q"}]}"#
+            ),
+            Err(e) => panic!("Error: {}", e),
+        }
+    }
+}