feat: Add two more rust tests (#82)

.vscode/settings.json

@@ -13,6 +13,7 @@
         "reqwest",
         "rollouts",
         "rustup",
-        "struct"
+        "struct",
+        "tempdir"
     ]
 }

updater/library/src/cache.rs

@@ -8,6 +8,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::network::{download_file_to_path, PatchCheckResponse};
 
+#[derive(PartialEq, Debug)]
 pub struct PatchInfo {
     pub path: String,
     pub version: String,
@@ -103,8 +104,7 @@ impl UpdaterState {
     }
 
     pub fn current_patch(&self) -> Option<PatchInfo> {
-        // If there is no state, return None.
-        if self.slots.is_empty() {
+        if self.slots.is_empty() || self.current_slot_index >= self.slots.len() {
             return None;
         }
         let slot = &self.slots[self.current_slot_index];
@@ -187,3 +187,18 @@ fn download_into_slot(
 
     return Ok(());
 }
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn current_patch_does_not_crash() {
+        let mut state = super::UpdaterState::default();
+        assert_eq!(state.current_patch(), None);
+        state.current_slot_index = 3;
+        assert_eq!(state.current_patch(), None);
+        state.slots.push(super::Slot::default());
+        // This used to crash, where index was bad, but slots were not empty.
+        assert_eq!(state.current_patch(), None);
+    }
+}

updater/library/src/network.rs

@@ -63,7 +63,9 @@ pub fn download_file_to_path(url: &str, path: &PathBuf) -> anyhow::Result<()> {
     let mut bytes = response.bytes()?;
 
     // Ensure the download directory exists.
-    std::fs::create_dir_all(path.parent().unwrap())?;
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent)?;
+    }
 
     let mut file = File::create(path)?;
     file.write_all(&mut bytes)?;

updater/library/src/updater.rs

@@ -1,6 +1,5 @@
 // This file's job is to be the Rust API for the updater.
 
-use std::fmt;
 use std::fmt::{Display, Formatter};
 
 use crate::cache::{download_into_unused_slot, PatchInfo, UpdaterState};
@@ -38,7 +37,7 @@ pub enum UpdateError {
 impl std::error::Error for UpdateError {}
 
 impl Display for UpdateError {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
         match self {
             UpdateError::InvalidArgument(name, value) => {
                 write!(f, "Invalid Argument: {} -> {}", name, value)
@@ -131,13 +130,16 @@ pub fn report_failed_launch() -> Result<(), UpdateError> {
     });
 }
 
-pub fn report_successful_launch() {
-    with_config(|config| {
+pub fn report_successful_launch() -> Result<(), UpdateError> {
+    return with_config(|config| {
         let mut state = UpdaterState::load(&config.cache_dir).unwrap_or_default();
 
-        let patch = state.current_patch().unwrap();
+        let patch = state
+            .current_patch()
+            .ok_or(UpdateError::InvalidState("No current patch".to_string()))?;
         state.mark_patch_as_good(&patch);
         state.save(&config.cache_dir).unwrap();
+        Ok(())
     });
 }
 
@@ -197,7 +199,7 @@ mod tests {
     }
 
     #[test]
-    fn report_failure_with_no_current() {
+    fn report_launch_result_with_no_current_patch() {
         init_for_testing();
         assert_eq!(
             crate::report_failed_launch(),
@@ -205,5 +207,11 @@ mod tests {
                 "No current patch".to_string()
             ))
         );
+        assert_eq!(
+            crate::report_successful_launch(),
+            Err(crate::UpdateError::InvalidState(
+                "No current patch".to_string()
+            ))
+        );
     }
 }