Add tests for utils and metadata

1 files changed, 65 insertions, 0 deletions

diff --git a/src/metadata.rs b/src/metadata.rs
index fe657e4..d6b3d6a 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -13,6 +13,11 @@ pub struct Metadata {
 }
 
 impl Metadata {
+    /// Reads `Metadata` from a file or creates a new one.
+    ///
+    /// This method will create new metadata if it can't read the file,
+    /// whether it's because of malformed JSON, UTF-8 or because the file
+    /// is not readable.
     pub fn read_or_create(file_path: &PathBuf) -> Metadata {
         if let Some(metadata) = Metadata::read_metadata_file(file_path) {
             metadata
@@ -28,6 +33,7 @@ impl Metadata {
         }
     }
 
+    /// Returns the metadata `created_on` as an RFC-2822 string.
     pub fn created_on_utc(&self) -> Option<String> {
         let date =
             OffsetDateTime::from_unix_timestamp_nanos((self.created_on * 1_000_000).into()).ok()?;
@@ -41,3 +47,62 @@ impl Metadata {
         serde_json::from_str(&contents).ok()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::fs::write;
+
+    use super::*;
+
+    use test_utilities::*;
+
+    #[test]
+    fn test_reads_metadata_if_file_exists() {
+        let test_dir = setup_test_dir();
+        create_test_file(
+            &test_dir.join("metadata.json"),
+            "\
+{
+    \"id\": \"cool\",
+    \"created_on\": 1736105008957
+}",
+        );
+
+        let metadata = Metadata::read_or_create(&test_dir.join("metadata.json"));
+
+        assert_eq!(metadata.id, "cool");
+        assert_eq!(metadata.created_on, 1736105008957);
+    }
+
+    #[test]
+    fn test_creates_metadata_if_file_does_not_exist() {
+        let test_dir = setup_test_dir();
+
+        assert!(!test_dir.join("metadata.json").exists());
+        let metadata = Metadata::read_or_create(&test_dir.join("metadata.json"));
+        assert_eq!(metadata.created_on.to_string(), metadata.id);
+    }
+
+    #[test]
+    fn test_creates_metadata_if_file_is_malformed() {
+        let test_dir = setup_test_dir();
+        write(&test_dir.join("metadata.json"), vec![0xFF, 0xFF]).expect("Failed to write file");
+
+        let metadata = Metadata::read_or_create(&test_dir.join("metadata.json"));
+        assert_eq!(metadata.created_on.to_string(), metadata.id);
+    }
+
+    #[test]
+    fn test_it_returns_created_on_as_rfc_2822_utc() {
+        let metadata = Metadata {
+            id: "cool".to_string(),
+            created_on: 1736035200000,
+        };
+
+        if let Some(created_on_utc) = metadata.created_on_utc() {
+            assert_eq!(created_on_utc, "Sun, 05 Jan 2025 00:00:00 +0000");
+        } else {
+            panic!("Could not generate RFC-2822 string");
+        }
+    }
+}