test: Add initial tests for exposed functions in lib

binary-install/src/lib.rs

@@ -47,7 +47,8 @@ where
     let bin = local_bin_dir(crate_path);
 
     for entry in archive.entries()? {
-        let mut entry = entry?;
+        let mut entry =
+            entry.map_err(|_err| Error::archive(&format!("Invalid tarball at {}", url)))?;
 
         let dest = match entry.path()?.file_stem() {
             Some(f) if binaries.contains(f) => {

binary-install/tests/test.rs

@@ -0,0 +1,73 @@
+extern crate binary_install;
+extern crate curl;
+extern crate failure;
+
+use binary_install::{error::Error, install_binaries_from_targz_at_url};
+use std::io::{Read, Write};
+use std::net::TcpListener;
+use std::path::Path;
+use std::thread;
+
+const SERVER_URL: &'static str = "localhost:7878";
+
+fn start_server() -> thread::JoinHandle<TcpListener> {
+    thread::spawn(|| {
+        let listener = TcpListener::bind(SERVER_URL).unwrap();
+        for stream in listener.incoming() {
+            let mut stream = stream.unwrap();
+
+            let mut buffer = [0; 512];
+
+            stream.read(&mut buffer).unwrap();
+
+            let response = "HTTP/1.1 200 OK\r\n\r\n";
+
+            stream.write(response.as_bytes()).unwrap();
+            stream.flush().unwrap();
+        }
+        listener
+    })
+}
+
+#[test]
+fn install_binaries_from_targz_at_url_should_return_http_error_for_bad_url() {
+    let crate_path = Path::new("");
+    let url = "";
+    let binaries = vec![""];
+
+    let result = install_binaries_from_targz_at_url(crate_path, url, binaries);
+    assert!(result.is_err());
+
+    let err = result.err().unwrap();
+    let err = err.downcast_ref::<Error>().unwrap();
+
+    let expected_message = format!("when requesting {}", url);
+
+    match err {
+        Error::Http { message } => assert_eq!(&expected_message, message),
+        _ => panic!("Wrong error returned"),
+    }
+}
+
+#[test]
+fn install_binaries_from_targz_at_url_should_return_archive_error_when_tarball_is_missing() {
+    let crate_path = Path::new("");
+    let url = format!("http://{}", SERVER_URL);
+    let binaries = vec![""];
+
+    // Spin up a local TcpListener.
+    start_server();
+
+    let result = install_binaries_from_targz_at_url(crate_path, &url, binaries);
+    assert!(result.is_err());
+
+    let err = result.err().unwrap();
+    let err = err.downcast_ref::<Error>().unwrap();
+
+    let expected_message = format!("Invalid tarball at {}", url);
+
+    match err {
+        Error::Archive { message } => assert_eq!(&expected_message, message),
+        _ => panic!("Wrong error returned"),
+    }
+}