test reading device uuid

src/gpt.rs

@@ -2,6 +2,13 @@ use crate::Device;
 #[cfg(feature = "gpt")]
 use gpt;
 
+
+#[cfg(not(test))]
+const DEV_DIR:&str = "/dev/";
+
+#[cfg(test)]
+const DEV_DIR:&str = concat!(env!("CARGO_MANIFEST_DIR"), "/resources", "/test");
+
 #[derive(Debug)]
 pub enum GptUUID {
     IoError(std::io::Error),
@@ -20,7 +27,7 @@ pub fn enrich_with_gpt_uuid(mut device: Device) -> Device {
 #[cfg(feature = "gpt")]
 pub fn enrich_with_gpt_uuid(mut device: Device) -> Device {
 
-    let diskpath = std::path::Path::new("/dev/").join(device.name.to_string());
+    let diskpath = std::path::Path::new(DEV_DIR).join(device.name.to_string());
     let cfg = gpt::GptConfig::new().writable(false);
     match cfg.open(diskpath) {
         Err(error) => device.uuid = GptUUID::IoError(error),
@@ -33,4 +40,32 @@ pub fn enrich_with_gpt_uuid(mut device: Device) -> Device {
     };
 
     device
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    #[cfg(feature = "gpt")]
+    #[test]
+    fn test_enrich_with_gpt_uuid() {
+        use crate::Size;
+
+        let mut device = Device {
+            name: "gptdisk.img".to_string(),
+            partitions: Vec::new(),
+            is_removable: false,
+            model: None,
+            serial: None,
+            size: Size::new(42),
+            uuid: GptUUID::NotAvailable,
+        };
+        device = enrich_with_gpt_uuid(device); 
+
+        match device.uuid {
+            GptUUID::UUID(uuid) => assert_eq!("f0ce7b2c-74af-47e4-8141-b2fe24ac20cc", uuid),
+            _ => panic!("No UUID"),
+        }                   
+    }
 }