tests: add test_binary_version as a poor safeguard

tests/integration_bin.rs

@@ -5,6 +5,23 @@ use utils::Sway;
 
 static SWAYSOME_BIN: &str = env!("CARGO_BIN_EXE_swaysome");
 
+// Poor safeguard that the tests are actually testing the right version, in
+// case there is some confusion with a swaysome installed from the system. That
+// obviously does not always worked, but has saved me a couple of times already 🙃
+#[test]
+fn test_binary_version() {
+    let output = Command::new(SWAYSOME_BIN)
+        .args(["--version"])
+        .env_clear()
+        .env("SWAYSOCK", "/dev/null")
+        .output()
+        .expect("Couldn't run swaysome");
+    assert_eq!(
+        String::from_utf8(output.stdout).unwrap(),
+        format!("swaysome {}\n", env!("CARGO_PKG_VERSION"))
+    );
+}
+
 // This is useful when working on swapping argument parsing libraries.
 #[test]
 fn test_binary_help() {