1 files changed, 74 insertions, 0 deletions
diff --git a/src/ip_service.rs b/src/ip_service.rs
new file mode 100644
index 0000000..8e2bee8
--- /dev/null
+++ b/src/ip_service.rs
@@ -0,0 +1,74 @@
+use reqwest::Url;
+use std::error::Error;
+use std::net::IpAddr;
+use std::str::FromStr;
+
+pub struct IpService {}
+
+impl IpService {
+    async fn resolve(config: &impl IpServiceConfiguration) -> Result<IpAddr, Box<dyn Error>> {
+        let response = reqwest::get(config.get_service_url()).await.unwrap();
+        Ok(IpAddr::from_str(&response.text().await.unwrap())?)
+    }
+}
+
+pub trait IpServiceConfiguration {
+    fn get_service_url(&self) -> Url;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::net::Ipv4Addr;
+    use wiremock::matchers::{method, path};
+    use wiremock::{Mock, MockServer, ResponseTemplate};
+
+    async fn setup_ipv4_service(service_path: &str, response: &str) -> MockServer {
+        let service = MockServer::start().await;
+
+        Mock::given(method("GET"))
+            .and(path(service_path))
+            .respond_with(
+                ResponseTemplate::new(200)
+                    .insert_header("Content-Type", "text/plain; charset=utf-8")
+                    .set_body_string(response),
+            )
+            .mount(&service)
+            .await;
+
+        service
+    }
+
+    #[tokio::test]
+    async fn successful_ipv4_address_resolution() -> Result<(), Box<dyn Error>> {
+        let service_path = "get-my-ip-address";
+        let service_response = "17.5.7.8";
+
+        let ip_service = setup_ipv4_service(service_path, service_response).await;
+        let service_config = MockConfig::new(&ip_service, service_path);
+
+        let actual = IpService::resolve(&service_config).await?;
+        assert_eq!(actual, IpAddr::V4(Ipv4Addr::new(17, 5, 7, 8)));
+
+        assert_eq!(1, ip_service.received_requests().await.unwrap().len());
+
+        Ok(())
+    }
+
+    struct MockConfig {
+        service_url: Url,
+    }
+
+    impl MockConfig {
+        fn new(server: &MockServer, path: &str) -> Self {
+            Self {
+                service_url: Url::parse(format!("{}/{}", server.uri(), path).as_str()).unwrap(),
+            }
+        }
+    }
+    impl IpServiceConfiguration for MockConfig {
+        fn get_service_url(&self) -> Url {
+            self.service_url.clone()
+        }
+    }
+}