docs(examples): replace unwraps with expects explaining why (#4001)

Just avoid unwrap as much as possible. Use expect to assert that it will always succeed.

Closes #3984

examples/params.rs

@@ -52,7 +52,7 @@ async fn param_example(
                 return Ok(Response::builder()
                     .status(StatusCode::UNPROCESSABLE_ENTITY)
                     .body(full(MISSING))
-                    .unwrap());
+                    .expect("constant status won't error"));
             };
             let number = if let Some(n) = params.get("number") {
                 if let Ok(v) = n.parse::<f64>() {
@@ -61,13 +61,13 @@ async fn param_example(
                     return Ok(Response::builder()
                         .status(StatusCode::UNPROCESSABLE_ENTITY)
                         .body(full(NOTNUMERIC))
-                        .unwrap());
+                        .expect("constant status won't error"));
                 }
             } else {
                 return Ok(Response::builder()
                     .status(StatusCode::UNPROCESSABLE_ENTITY)
                     .body(full(MISSING))
-                    .unwrap());
+                    .expect("constant status won't error"));
             };
 
             // Render the response. This will often involve
@@ -86,7 +86,7 @@ async fn param_example(
                 return Ok(Response::builder()
                     .status(StatusCode::UNPROCESSABLE_ENTITY)
                     .body(full(MISSING))
-                    .unwrap());
+                    .expect("constant status won't error"));
             };
             let params = form_urlencoded::parse(query.as_bytes())
                 .into_owned()
@@ -97,7 +97,7 @@ async fn param_example(
                 return Ok(Response::builder()
                     .status(StatusCode::UNPROCESSABLE_ENTITY)
                     .body(full(MISSING))
-                    .unwrap());
+                    .expect("constant status won't error"));
             };
             let body = format!("You requested {}", page);
             Ok(Response::new(full(body)))
@@ -105,7 +105,7 @@ async fn param_example(
         _ => Ok(Response::builder()
             .status(StatusCode::NOT_FOUND)
             .body(empty())
-            .unwrap()),
+            .expect("constant status won't error")),
     }
 }
 

examples/send_file.rs

@@ -61,7 +61,7 @@ fn not_found() -> Response<BoxBody<Bytes, std::io::Error>> {
     Response::builder()
         .status(StatusCode::NOT_FOUND)
         .body(Full::new(NOTFOUND.into()).map_err(|e| match e {}).boxed())
-        .unwrap()
+        .expect("constant status won't error")
 }
 
 async fn simple_file_send(filename: &str) -> Result<Response<BoxBody<Bytes, std::io::Error>>> {
@@ -85,7 +85,7 @@ async fn simple_file_send(filename: &str) -> Result<Response<BoxBody<Bytes, std:
     let response = Response::builder()
         .status(StatusCode::OK)
         .body(boxed_body)
-        .unwrap();
+        .expect("constant status won't error");
 
     Ok(response)
 }

examples/service_struct_impl.rs

@@ -51,7 +51,7 @@ impl Service<Request<IncomingBody>> for Svc {
 
     fn call(&self, req: Request<IncomingBody>) -> Self::Future {
         fn mk_response(s: String) -> Result<Response<Full<Bytes>>, hyper::Error> {
-            Ok(Response::builder().body(Full::new(Bytes::from(s))).unwrap())
+            Ok(Response::new(Full::new(Bytes::from(s))))
         }
 
         if req.uri().path() != "/favicon.ico" {

examples/upgrades.rs

@@ -100,7 +100,7 @@ async fn client_upgrade_request(addr: SocketAddr) -> Result<()> {
         .uri(format!("http://{}/", addr))
         .header(UPGRADE, "foobar")
         .body(Empty::<Bytes>::new())
-        .unwrap();
+        .expect("uri/header parse won't error");
 
     let stream = TcpStream::connect(addr).await?;
     let io = TokioIo::new(stream);

examples/web_api.rs

@@ -29,7 +29,7 @@ async fn client_request_response() -> Result<Response<BoxBody>> {
         .uri(URL)
         .header(header::CONTENT_TYPE, "application/json")
         .body(Full::new(Bytes::from(POST_DATA)))
-        .unwrap();
+        .expect("uri/header parse from constants won't error");
 
     let host = req.uri().host().expect("uri has no host");
     let port = req.uri().port_u16().expect("uri has no port");
@@ -73,11 +73,11 @@ async fn api_get_response() -> Result<Response<BoxBody>> {
         Ok(json) => Response::builder()
             .header(header::CONTENT_TYPE, "application/json")
             .body(full(json))
-            .unwrap(),
+            .expect("header parse from constant won't error"),
         Err(_) => Response::builder()
             .status(StatusCode::INTERNAL_SERVER_ERROR)
             .body(full(INTERNAL_SERVER_ERROR))
-            .unwrap(),
+            .expect("constant status won't error"),
     };
     Ok(res)
 }
@@ -93,7 +93,7 @@ async fn response_examples(req: Request<IncomingBody>) -> Result<Response<BoxBod
             Ok(Response::builder()
                 .status(StatusCode::NOT_FOUND)
                 .body(full(NOTFOUND))
-                .unwrap())
+                .expect("constant status won't error"))
         }
     }
 }