Add regression test for components

tests/components.rs

@@ -0,0 +1,17 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+#[test]
+fn test_components() {
+    use std::env::var;
+
+    let mut c = sysinfo::Components::new();
+    assert!(c.is_empty());
+
+    // Unfortunately, we can't get components in the CI...
+    if !sysinfo::IS_SUPPORTED_SYSTEM || cfg!(windows) || var("CI").is_ok() {
+        return;
+    }
+
+    c.refresh_list();
+    assert!(!c.is_empty());
+}