create failing test for run

Cargo.lock

@@ -325,6 +325,12 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "diff"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
+
 [[package]]
 name = "diligent-date-parser"
 version = "0.1.4"
@@ -1016,6 +1022,7 @@ dependencies = [
  "atom_syndication",
  "bytes",
  "clap",
+ "pretty_assertions",
  "reqwest",
  "scraper",
  "tempfile",
@@ -1033,6 +1040,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 
+[[package]]
+name = "pretty_assertions"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af7cee1a6c8a5b9208b3cb1061f10c0cb689087b3d8ce85fb9d2dd7a29b6ba66"
+dependencies = [
+ "diff",
+ "yansi",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.66"
@@ -1726,3 +1743,9 @@ checksum = "80d0f4e272c85def139476380b12f9ac60926689dd2e01d4923222f40580869d"
 dependencies = [
  "winapi",
 ]
+
+[[package]]
+name = "yansi"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09041cd90cf85f7f8b2df60c646f853b7f535ce68f85244eb6731cf89fa498ec"

Cargo.toml

@@ -14,3 +14,4 @@ bytes = "1.4.0"
 
 [dev-dependencies]
 tempfile = "*"
+pretty_assertions = "*"

src/errors.rs

@@ -37,6 +37,13 @@ impl From<std::io::Error> for Error {
         }
     }
 }
+impl From<std::sync::mpsc::SendError<String>> for Error {
+    fn from(value: std::sync::mpsc::SendError<String>) -> Self {
+        Self {
+            details: value.to_string(),
+        }
+    }
+}
 impl From<atom_syndication::Error> for Error {
     fn from(value: atom_syndication::Error) -> Self {
         Self {

src/lib.rs

@@ -37,12 +37,84 @@ pub fn run(subscriptions: &str, history: &str, site: &str, e: Env) -> Result<()>
 
 #[cfg(test)]
 mod tests {
+    use std::{collections::HashMap, sync::mpsc};
+
+    use atom_syndication::{Entry, EntryBuilder, Feed, FeedBuilder, LinkBuilder, Text};
+
+    use crate::test_utils::{
+        create_text_file, mock_fetch_as_text_with_rss_url, mock_file_append_line, mock_file_open,
+        mock_network_download_as_mp3, mock_network_fetch_as_bytes_with_rss_entries,
+    };
+    use pretty_assertions::assert_eq;
+
     use super::*;
+
     #[test]
     fn downloads_two_items_from_two_feeds_ignoring_existing_items_in_history() -> Result<()> {
         //given
+
+        let site = "http://example.com/";
+        let (tx, rx) = mpsc::channel::<String>(); // channel to recieve notice of downloaded urls
+
+        // two channels in subscriptions.txt
+        let (subs_dir, subs_file_name) =
+            create_text_file("subs", "@channel1\nignore me\n@channel2".as_bytes())?;
+        // one item from each channel is already listed in the downloads.txt file
+        let (history_dir, history_file_name) =
+            create_text_file("history", "c1-f2\nc2-f3".as_bytes())?;
+
+        let env = Env {
+            network: NetworkEnv {
+                fetch_as_text: mock_fetch_as_text_with_rss_url(HashMap::from([
+                    ("http://example.com/@channel1", "rss-feed-1"),
+                    ("http://example.com/@channel2", "rss-feed-2"),
+                ])),
+                fetch_as_bytes: mock_network_fetch_as_bytes_with_rss_entries(HashMap::from([
+                    (
+                        "rss-feed-1".into(),
+                        feed_with_three_links("c1-f1", "c1-f2", "c1-f3").to_string(),
+                    ),
+                    (
+                        "rss-feed-2".into(),
+                        feed_with_three_links("c2-f1", "c2-f2", "c2-f3").to_string(),
+                    ),
+                ])),
+                download_as_mp3: mock_network_download_as_mp3(tx),
+            },
+            file: FileEnv {
+                open: mock_file_open(vec![subs_file_name.clone()]),
+                append_line: mock_file_append_line(),
+            },
+        };
+
         //when
+        run(&subs_file_name, &history_file_name, site, env)?;
         //then
+        drop(subs_dir);
+        drop(history_dir);
+
+        let mut downloads: Vec<String> = vec![];
+        for m in rx {
+            downloads.push(m);
+        }
+
+        assert_eq!(downloads, vec!["c1-f1", "c1-f3", "c2-f1", "c2-f2"]);
         Ok(())
     }
+
+    fn entry_with_link(link: &str, title: &str) -> Entry {
+        EntryBuilder::default()
+            .links(vec![LinkBuilder::default().href(link.to_string()).build()])
+            .title(Text::from(title))
+            .build()
+    }
+    fn feed_with_three_links(l1: &str, l2: &str, l3: &str) -> Feed {
+        FeedBuilder::default()
+            .entries(vec![
+                entry_with_link(l1, "l1"),
+                entry_with_link(l2, "l2"),
+                entry_with_link(l3, "l3"),
+            ])
+            .build()
+    }
 }

src/test_utils.rs

@@ -3,6 +3,7 @@ use std::{
     fs::{read_to_string, File},
     io::Write,
     str::from_utf8,
+    sync::mpsc::Sender,
 };
 
 use tempfile::{tempdir, TempDir};
@@ -69,8 +70,15 @@ pub fn mock_file_open(real_paths: Vec<String>) -> FileOpenFn {
     })
 }
 
-pub fn mock_network_download_as_mp3() -> NetworkDownloadAsMp3Fn {
-    Box::new(|_url| Ok(()))
+pub fn mock_network_download_as_mp3(tx: Sender<String>) -> NetworkDownloadAsMp3Fn {
+    Box::new(move |url: &str| {
+        tx.send(url.into())?;
+        Ok(())
+    })
+}
+
+pub fn mock_file_append_line() -> FileAppendLineFn {
+    Box::new(|_, _| Ok(()))
 }
 
 pub fn stub_network_fetch_as_bytes() -> NetworkFetchAsBytesFn {
@@ -94,10 +102,10 @@ pub fn stub_network_download_as_mp3() -> NetworkDownloadAsMp3Fn {
 //         ))
 //     })
 // }
-pub fn stub_file_append_line() -> FileAppendLineFn {
-    Box::new(|path: &str, line: &str| {
-        Err(Error::message(
-            format!("Not implemented: file_append_line: {} to {}", line, path).as_str(),
-        ))
-    })
-}
+// pub fn stub_file_append_line() -> FileAppendLineFn {
+//     Box::new(|path: &str, line: &str| {
+//         Err(Error::message(
+//             format!("Not implemented: file_append_line: {} to {}", line, path).as_str(),
+//         ))
+//     })
+// }