feat: add support for parsing auto_update from shorebird.yaml (#65)

* feat: add support for parsing auto_update from shorebird.yaml

The actual support will be in the C++ engine, but this keeps
all yaml parsing in the Rust code for simplicity.

---------

Co-authored-by: Felix Angelov <felix@shorebird.dev>

library/include/updater.h

@@ -55,6 +55,11 @@ SHOREBIRD_EXPORT
 bool shorebird_init(const struct AppParameters *c_params,
                     const char *c_yaml);
 
+/**
+ * Returns if the app should run the updater automatically on launch.
+ */
+SHOREBIRD_EXPORT bool shorebird_should_auto_update(void);
+
 /**
  * The currently running patch number, or 0 if the release has not been
  * patched.

library/src/c_api.rs

@@ -109,6 +109,16 @@ pub extern "C" fn shorebird_init(
     )
 }
 
+/// Returns if the app should run the updater automatically on launch.
+#[no_mangle]
+pub extern "C" fn shorebird_should_auto_update() -> bool {
+    log_on_error(
+        || updater::should_auto_update(),
+        "fetching update behavior",
+        true,
+    )
+}
+
 /// The currently running patch number, or 0 if the release has not been
 /// patched.
 #[no_mangle]
@@ -336,6 +346,25 @@ mod test {
         free_parameters(c_params);
     }
 
+    #[serial]
+    #[test]
+    fn yaml_parsing() {
+        testing_reset_config();
+        let tmp_dir = TempDir::new("example").unwrap();
+        let c_params = parameters(&tmp_dir, "/dir/lib/arm64/libapp.so");
+        let c_yaml = c_string(
+            "
+        app_id: foo
+        channel: bar
+        base_url: baz
+        auto_update: false",
+        );
+        assert_eq!(shorebird_init(&c_params, c_yaml), true);
+        free_c_string(c_yaml);
+        free_parameters(c_params);
+        assert_eq!(shorebird_should_auto_update(), false);
+    }
+
     #[serial]
     #[test]
     fn empty_state_no_update() {

library/src/cache.rs

@@ -88,6 +88,8 @@ impl UpdaterState {
         self.failed_patches.iter().any(|v| v == &patch_number)
     }
 
+    // TODO(eseidel): Should return Result instead of logging, the c_api
+    // layer can log if desired.
     pub fn mark_patch_as_bad(&mut self, patch_number: usize) {
         if self.is_known_good_patch(patch_number) {
             warn!("Tried to report failed launch for a known good patch.  Ignoring.");
@@ -102,6 +104,8 @@ impl UpdaterState {
         self.failed_patches.push(patch_number);
     }
 
+    // TODO(eseidel): Should return Result instead of logging, the c_api
+    // layer can log if desired.
     pub fn mark_patch_as_good(&mut self, patch_number: usize) {
         if self.is_known_bad_patch(patch_number) {
             warn!("Tried to report successful launch for a known bad patch.  Ignoring.");

library/src/config.rs

@@ -73,6 +73,7 @@ where
 pub struct UpdateConfig {
     pub cache_dir: PathBuf,
     pub download_dir: PathBuf,
+    pub auto_update: bool,
     pub channel: String,
     pub app_id: String,
     pub release_version: String,
@@ -102,6 +103,7 @@ pub fn set_config(
                 .as_deref()
                 .unwrap_or(DEFAULT_CHANNEL)
                 .to_owned(),
+            auto_update: yaml.auto_update.unwrap_or(true),
             app_id: yaml.app_id.to_string(),
             release_version: app_config.release_version.to_string(),
             libapp_path,

library/src/updater.rs

@@ -117,6 +117,10 @@ pub fn init(app_config: AppConfig, yaml: &str) -> Result<(), UpdateError> {
         .map_err(|err| UpdateError::InvalidState(err.to_string()))
 }
 
+pub fn should_auto_update() -> anyhow::Result<bool> {
+    with_config(|config| Ok(config.auto_update))
+}
+
 fn check_for_update_internal() -> anyhow::Result<PatchCheckResponse> {
     with_config(|config| {
         // Load UpdaterState from disk

library/src/yaml.rs

@@ -10,6 +10,8 @@ pub struct YamlConfig {
     pub channel: Option<String>,
     /// Update URL.  Defaults to the default update URL if not set.
     pub base_url: Option<String>,
+    /// Update behavior. Defaults to true if not set.
+    pub auto_update: Option<bool>,
 }
 
 impl YamlConfig {