From 5f2371da2e3bea711fb8ea796fe6fee0999cd2b7 Mon Sep 17 00:00:00 2001
From: Andreas Rammhold <andreas@rammhold.de>
Date: Tue, 21 Apr 2020 00:17:28 +0200
Subject: [PATCH] fix(list_sync): make sure the public interface allows using
 the Item type

Before this change the public interface wouldn't allow downstream users
to use the actual items since it wasn't communicated on the function
signature.

Previously a user would run into erorrs like this:
> no field `key` on type `<impl std::iter::Iterator as std::iter::Iterator>::Item`
---
 src/ls.rs | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/ls.rs b/src/ls.rs
index 90670da..acfe27e 100644
--- a/src/ls.rs
+++ b/src/ls.rs
@@ -1,9 +1,29 @@
 //! Functions for iterating over the cache.
+use anyhow::Result;
 use std::path::Path;
 
 use crate::index;
 
 /// Returns a synchronous iterator that lists all cache index entries.
-pub fn list_sync<P: AsRef<Path>>(cache: P) -> impl Iterator {
+pub fn list_sync<P: AsRef<Path>>(cache: P) -> impl Iterator<Item = Result<index::Metadata>> {
     index::ls(cache.as_ref())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile;
+
+    #[test]
+    fn test_list_sync() {
+        // check that the public interface to list elements can actually use the
+        // Iterator::Item
+        let tmp = tempfile::tempdir().unwrap();
+        let dir = tmp.path().to_owned();
+
+        assert!(list_sync(dir)
+            .map(|x| Ok(x?.key))
+            .collect::<Result<Vec<_>>>()
+            .is_err())
+    }
+}