feat: add preview update channel

1 files changed, 44 insertions, 0 deletions

diff --git a/src/build_info.rs b/src/build_info.rs
new file mode 100644
index 00000000..1fdedfbb
--- /dev/null
+++ b/src/build_info.rs
@@ -0,0 +1,44 @@
+//! Build identity helpers.
+
+pub const BASE_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+pub fn channel() -> &'static str {
+    non_empty(option_env!("HERDR_BUILD_CHANNEL")).unwrap_or("stable")
+}
+
+pub fn build_id() -> Option<&'static str> {
+    non_empty(option_env!("HERDR_BUILD_ID"))
+}
+
+pub fn version() -> String {
+    match channel() {
+        "stable" => BASE_VERSION.to_string(),
+        channel => match build_id() {
+            Some(build_id) => format!("{BASE_VERSION}-{channel}.{build_id}"),
+            None => format!("{BASE_VERSION}-{channel}"),
+        },
+    }
+}
+
+pub fn is_preview() -> bool {
+    channel() == "preview"
+}
+
+fn non_empty(value: Option<&'static str>) -> Option<&'static str> {
+    value.and_then(|value| {
+        let trimmed = value.trim();
+        if trimmed.is_empty() {
+            None
+        } else {
+            Some(trimmed)
+        }
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn stable_version_defaults_to_cargo_version() {
+        assert!(!super::version().is_empty());
+    }
+}