libcnb-test: Improve the ergonomics of ContainerContext::address_for_port

CHANGELOG.md

@@ -12,6 +12,7 @@ separate changelogs for each crate were used. If you need to refer to these old
 
 ### Changed
 
+- `libcnb-test`: `ContainerContext::address_for_port` now returns `SocketAddr` directly instead of `Option<SocketAddr>`. ([#605](https://github.com/heroku/libcnb.rs/pull/605))
 - `libcnb-package`: buildpack target directory now contains the target triple. Users that implicitly rely on the output directory need to adapt. The output of `cargo 
 libcnb package` will refer to the new locations. ([#580](https://github.com/heroku/libcnb.rs/pull/580))
 - `libherokubuildpack`: Switch the `flate2` decompression backend from `miniz_oxide` to `zlib`. ([#593](https://github.com/heroku/libcnb.rs/pull/593))

examples/ruby-sample/tests/integration_test.rs

@@ -35,7 +35,7 @@ fn basic() {
 
                 assert_eq!(
                     call_test_fixture_service(
-                        container.address_for_port(TEST_PORT).unwrap(),
+                        container.address_for_port(TEST_PORT),
                         "Hello World!"
                     )
                     .unwrap(),

libcnb-test/README.md

@@ -123,7 +123,7 @@ fn starting_web_server_container() {
                     .env("PORT", TEST_PORT.to_string())
                     .expose_port(TEST_PORT),
                 |container| {
-                    let address_on_host = container.address_for_port(TEST_PORT).unwrap();
+                    let address_on_host = container.address_for_port(TEST_PORT);
                     let url = format!("http://{}:{}", address_on_host.ip(), address_on_host.port());
 
                     // Give the server time to start.

libcnb-test/src/container_config.rs

@@ -128,7 +128,7 @@ impl ContainerConfig {
     ///         context.start_container(
     ///             ContainerConfig::new().env("PORT", "12345").expose_port(12345),
     ///             |container| {
-    ///                 let address_on_host = container.address_for_port(12345).unwrap();
+    ///                 let address_on_host = container.address_for_port(12345);
     ///                 // ...
     ///             },
     ///         );

libcnb-test/src/container_context.rs

@@ -113,15 +113,20 @@ impl<'a> ContainerContext<'a> {
     ///         context.start_container(
     ///             ContainerConfig::new().env("PORT", "12345").expose_port(12345),
     ///             |container| {
-    ///                 let address_on_host = container.address_for_port(12345).unwrap();
+    ///                 let address_on_host = container.address_for_port(12345);
     ///                 // ...
     ///             },
     ///         );
     ///     },
     /// );
     /// ```
+    ///
+    /// # Panics
+    ///
+    /// Will panic if there was an error obtaining the container port mapping, or the specified port
+    /// was not exposed using [`ContainerConfig::expose_port`](crate::ContainerConfig::expose_port).
     #[must_use]
-    pub fn address_for_port(&self, port: u16) -> Option<SocketAddr> {
+    pub fn address_for_port(&self, port: u16) -> SocketAddr {
         self.test_context.runner.tokio_runtime.block_on(async {
             self.test_context
                 .runner
@@ -137,6 +142,7 @@ impl<'a> ContainerContext<'a> {
                         .get(&port)
                         .copied()
                 })
+                .expect("Could not find specified port in container port mapping")
         })
     }
 

libcnb-test/tests/integration_test.rs

@@ -68,7 +68,7 @@ fn starting_containers() {
                     .env("PORT", TEST_PORT.to_string())
                     .expose_port(TEST_PORT),
                 |container| {
-                    let address_on_host = container.address_for_port(TEST_PORT).unwrap();
+                    let address_on_host = container.address_for_port(TEST_PORT);
                     let url = format!("http://{}:{}", address_on_host.ip(), address_on_host.port());
 
                     // Retries needed since the server takes a moment to start up.