Release version 0.2.3

Signed-off-by: Jacob Kiers <jacob@jacobkiers.net>

.cargo/config.toml

@@ -0,0 +1,3 @@
+[profile.release]
+lto = "thin"
+strip = true

.drone.jsonnet

@@ -1,31 +1,26 @@
 local executableName = 'newsletter-to-web';
+local cross_image = 'img.kie.rs/jjkiers/rust-dind-cross:1.66-full';
 
 local archs = [
-  { target: 'aarch64-unknown-linux-gnu', short: 'arm64-gnu' },
   { target: 'aarch64-unknown-linux-musl', short: 'arm64-musl' },
   { target: 'x86_64-pc-windows-gnu', short: 'windows' },
-  { target: 'x86_64-unknown-linux-gnu', short: 'amd64-gnu' },
   { target: 'x86_64-unknown-linux-musl', short: 'amd64-musl' },
 ];
 
 local getStepName(arch) = 'Build for ' + arch.short;
 
-local builtExecutableName(arch) = executableName + if std.startsWith(arch.short, 'windows') then '.exe' else '';
-local targetExecutableName(arch) = executableName + if std.startsWith(arch.short, 'windows') then '.exe' else '-' + arch.short;
+local builtExecutableName(arch) = executableName + if std.length(std.findSubstr(arch.short, 'windows')) > 0 then '.exe' else '';
+local targetExecutableName(arch) = executableName + '-' + arch.target + if std.length(std.findSubstr(arch.short, 'windows')) > 0 then '.exe' else '';
 
 local add_build_steps() = [
   {
     name: getStepName(arch),
-    image: 'img.kie.rs/jjkiers/rust-dind-cross:1.62-slim',
+    image: cross_image,
     volumes: [
       {
         name: 'dockersock',
         path: '/var/run',
       },
-      {
-        name: 'rustup',
-        path: '/usr/local/rustup',
-      },
     ],
     commands: [
       'echo Hello World from Jsonnet on ' + arch.target + '!',
@@ -51,13 +46,19 @@ local add_build_steps() = [
   steps:
     [{
       name: 'Wait for Docker',
-      image: 'img.kie.rs/jjkiers/rust-dind-cross:1.62-slim',
+      image: cross_image,
       commands: [
+        'mkdir artifacts',
+        'echo Using image: ' + cross_image,
         'while ! docker image ls; do sleep 1; done',
+        'cargo --version',
+        'rustc --version',
         'docker info',
         'docker pull hello-world:latest',
-        'mkdir artifacts',
       ],
+      environment: {
+        CROSS_REMOTE: true,
+      },
       volumes: [{
         name: 'dockersock',
         path: '/var/run',
@@ -67,7 +68,7 @@ local add_build_steps() = [
     [
       {
         name: 'Show built artifacts',
-        image: 'img.kie.rs/jjkiers/rust-dind-cross:1.62-slim',
+        image: cross_image,
         commands: [
           'ls -lah artifacts',
         ],
@@ -112,18 +113,6 @@ local add_build_steps() = [
       name: 'dockersock',
       temp: {},
     },
-    {
-      name: 'docker-storage',
-      host: {
-        path: '/srv/drone/docker-dind-rust',
-      },
-    },
-    {
-      name: 'rustup',
-      host: {
-        path: '/srv/drone/rustup',
-      },
-    },
   ],
 
   image_pull_secrets: ['docker_private_repo'],

CHANGELOG.md

@@ -0,0 +1,44 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [0.2.3] - 2022-12-29
+
+### Added
+
+* Added `update` subcommand to update to the latest version.
+
+### Fixed
+
+* Truncate feed file before writing, to prevent corruption from leftover data.
+* Ensure the feed file name is part of the self URL. This was still hardcoded to `feed.atom`.
+
+## [0.2.2] - 2022-12-16
+
+### Changed
+
+* Updated build pipeline to generate much smaller binaries
+
+## [0.2.1] - 2022-12-13
+
+### Changed
+
+* Updated the [mail-parser](https://docs.rs/crate/mail-parser/0.8.0) crate to v0.8.0.
+* Removed two builds from the build pipeline.
+
+
+## [0.2.0] - 2022-11-30
+
+### Added
+
+* A style sheet is added to the feed for easy readability in a web browser (#4).
+* The output directory will now contain an index.html file with some information.
+
+### Changed
+
+* By default, the name of the feed is now feed.xml instead of feed.atom.

Cargo.toml

@@ -1,5 +1,25 @@
-[workspace]
-
-members = [
-    "bin",
+[package]
+name = "newsletter-to-web"
+version = "0.2.3"
+edition = "2021"
+description = "Converts email newsletters to static HTML files"
+homepage = "https://code.kiers.eu/newsletter-to-web/newsletter-to-web"
+authors = [
+    "Jacob Kiers <code@kiers.eu>"
 ]
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+atom_syndication = "^0.11.0"
+base16ct = { version = "^0.1.0", features = [ "alloc" ] }
+chrono = "^0.4"
+clap = { version = "^4.0.22", features = [ "derive" ] }
+imap = { version = "^2.4.1", default-features = false }
+mail-parser = "^0.8.0"
+rustls-connector = { version = "^0.16.1", default-features = false, features = [ "webpki-roots-certs", "quic" ] }
+sha2 = "^0.10.2"
+self_update = { version = "0.33.0", default-features = false, features = ["rustls"] }
+
+[patch.crates-io]
+atom_syndication = { git = "https://github.com/rust-syndication/atom", rev = "5cf8d161e5e5af7d93cca8d2c117b7af879a99b7" }

README.md

@@ -1,6 +1,41 @@
-# Newsletter 2 Web
+# Newsletter to Web
 
-Converts a newsletter to static HTML files.
+Converts a newsletter to and Atom feed and static HTML files.
+
+## Usage
+
+Get the latest release [from the releases page](https://code.kiers.eu/newsletter-to-web/newsletter-to-web/releases/latest).
+
+### Getting help
+
+For help, use 
+
+* `newsletter-to-web help`
+* `newsletter-to-web help <subcommand>`.
+
+### Basic usage
+
+First, download all messages from the IMAP mail server 
+and store them in the `data/` directory:
+
+```sh
+newsletter-to-web fetch-from-imap -s <imap.example.com> -u <email@example.com> -p <password>
+```
+
+Then, convert them to an Atom feed, using
+`newsletters.example.com` as the base domain:
+
+```sh
+newsletter-to-web --include-html build-feed newsletters.example.org
+```
+
+This will put the output in the `output/` directory. The Atom
+feed will be in `output/feed.xml`, together with a very simple
+`index.html` file pointing to the feed. It will also add an HTML
+file for every email with the HTML content.
+
+The feed will already contain the full HTML, so it can easily be
+read from a feed reader.
 
 ## Features
 

bin/Cargo.toml

@@ -1,20 +0,0 @@
-[package]
-name = "newsletter-to-web"
-version = "0.1.0"
-edition = "2021"
-description = "Converts email newsletters to static HTML files"
-authors = [
-    "Jacob Kiers <code@kiers.eu>"
-]
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-atom_syndication = "^0.11.0"
-base16ct = { version = "^0.1.0", features = [ "alloc" ] }
-chrono = "^0.4"
-clap = { version = "^3.2.16", features = [ "derive" ] }
-imap = { version = "^2.4.1", default-features = false }
-mail-parser = "^0.5.0"
-rustls-connector = { version = "^0.16.1", default-features = false, features = [ "webpki-roots-certs", "quic" ] }
-sha2 = "^0.10.2"

resources/feed.xsl

@@ -0,0 +1,78 @@
+<xsl:stylesheet
+  version="1.0"
+  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+  xmlns:atom="http://www.w3.org/2005/Atom"
+  exclude-result-prefixes="atom"
+>
+  <xsl:output method="html" version="1.0" encoding="UTF-8" indent="yes"/>
+  <xsl:template match="/">
+    <html xmlns="http://www.w3.org/1999/xhtml">
+      <head>
+        <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
+        <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"/>
+        <title>Web Feed • <xsl:value-of select="atom:feed/atom:title"/></title>
+        <style type="text/css">
+          body{max-width:768px;margin:0 auto;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Helvetica,Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol";font-size:16px;line-height:1.5em}section{margin:30px 15px}h1{font-size:2em;margin:.67em 0;line-height:1.125em}h2{border-bottom:1px solid #eaecef;padding-bottom:.3em}.alert{background:#fff5b1;padding:4px 12px;margin:0 -12px}a{text-decoration:none}.entry h3{margin-bottom:0}.entry p{margin:4px 0}
+        </style>
+      </head>
+      <body>
+        <section>
+          <div class="alert">
+            <p><strong>This is a web feed</strong>, also known as an RSS feed. <strong>Subscribe</strong> by copying the URL from the address bar into your newsreader app.</p>
+          </div>
+        </section>
+        <section>
+          <xsl:apply-templates select="atom:feed" />
+        </section>
+        <section>
+          <h2>Recent Items</h2>
+          <p>Last updated on <xsl:apply-templates select="atom:feed/atom:updated" /></p>
+          <xsl:apply-templates select="atom:feed/atom:entry" />
+        </section>
+      </body>
+    </html>
+  </xsl:template>
+
+  <xsl:template match="atom:feed">
+    <h1><xsl:value-of select="atom:title"/>'s Web Feed Preview</h1>
+    <p>This RSS feed provides the latest posts from <xsl:value-of select="atom:title"/>'s blog.
+
+    <a class="head_link" target="_blank">
+      <xsl:attribute name="href">
+        <xsl:value-of select="atom:link[@rel='alternate']/@href"/>
+      </xsl:attribute>
+      Visit Website &#x2192;
+    </a>
+
+    </p>
+
+    <h2>What is an RSS feed?</h2>
+    <p>An RSS feed is a data format that contains the latest content from a website, blog, or podcast. You can use feeds to <strong>subscribe</strong> to websites and get the <strong>latest content in one place</strong>.</p>
+    <ul>
+    	<li><strong>Feeds put you in control.</strong> Unlike social media apps, there is no algorithm deciding what you see or read. You always get the latest content from the creators you care about.</li>
+    	<li><strong>Feed are private by design.</strong> No one owns web feeds, so no one is harvesting your personal information and profiting by selling it to advertisers.</li>
+    	<li><strong>Feeds are spam-proof.</strong> Had enough? Easy, just unsubscribe from the feed.</li>
+    </ul>
+    <p>All you need to do to get started is to add the URL (web address) for this feed to a special app called a newsreader. Visit <a href="https://aboutfeeds.com/">About Feeds</a> to get started with newsreaders and subscribing. It’s free. </p>
+  </xsl:template>
+
+  <xsl:template match="atom:entry">
+    <div class="entry">
+      <h3>
+        <a target="_blank">
+          <xsl:attribute name="href">
+            <xsl:value-of select="atom:id"/>
+          </xsl:attribute>
+          <xsl:value-of select="atom:title"/>
+        </a>
+      </h3>
+      <p>
+        <xsl:value-of select="atom:summary"  disable-output-escaping="yes" />
+      </p>
+      <small>
+        Published: <xsl:value-of select="atom:updated" />
+      </small>
+    </div>
+  </xsl:template>
+
+</xsl:stylesheet>

resources/index.html

@@ -1,8 +1,12 @@
 <!DOCTYPE html>
 <html>
-    <head><title>Newsletters</title></head>
+    <head>
+        <title>Newsletters</title>
+        <link rel="alternate" type="application/atom+xml" title="ATOM feed" href="./{FEED}" />
+    </head>
     <body>
         <h1>Newsletters 2 Web</h1>
+        <p>The real feed can be found at <a href="./{FEED}">{FEED}</a></p>
         <p>Nothing to see here.</p>
         <p>This is a public landing page for an instance of the
             <a href="https://code.kiers.eu/newsletter-to-web/newsletter-to-web">Newsletters 2 Web</a>

src/cli.rs

@@ -32,7 +32,7 @@ pub(crate) enum Command {
         /// Host name hosting the feed
         hostname: String,
         /// Feed file
-        #[clap(value_parser, default_value = "output/feed.atom")]
+        #[clap(value_parser, default_value = "output/feed.xml")]
         filename: PathBuf,
         /// Create an HTML file for each message
         #[clap(short, long, value_parser, default_value_t = false)]
@@ -50,4 +50,6 @@ pub(crate) enum Command {
         #[clap(value_parser, default_value = "output/")]
         directory: PathBuf,
     },
+    /// Update to the latest version
+    Update,
 }

src/command.rs

@@ -0,0 +1 @@
+pub(crate) mod update;

src/command/update.rs

@@ -0,0 +1,17 @@
+use self_update::cargo_crate_version;
+use std::error::Error;
+
+pub(crate) fn self_update() -> Result<(), Box<dyn Error>> {
+    let backend = self_update::backends::gitea::Update::configure()
+        .with_host("https://code.kiers.eu")
+        .repo_owner("newsletter-to-web")
+        .repo_name("newsletter-to-web")
+        .bin_name("newsletter-to-web")
+        .show_download_progress(true)
+        .current_version(cargo_crate_version!())
+        .build()?;
+
+    let status = backend.update()?;
+    println!("Update status: `{}`!", status.version());
+    Ok(())
+}

src/feed.rs

@@ -2,6 +2,7 @@ use crate::Message;
 
 use atom_syndication::{
     ContentBuilder, Entry, EntryBuilder, Feed, FeedBuilder, Generator, LinkBuilder, Person,
+    WriteConfig,
 };
 use chrono::{DateTime, TimeZone, Utc};
 
@@ -15,8 +16,8 @@ pub(crate) fn add_entry_to_feed(
     include_html: bool,
 ) {
     let parsed = message.get_parsed().unwrap();
-    let date = parsed.get_date().expect("Could not extract date");
-    let from = match parsed.get_from() {
+    let date = parsed.date().expect("Could not extract date");
+    let from = match parsed.from() {
         HeaderValue::Address(e) => e,
         _ => return,
     };
@@ -34,43 +35,38 @@ pub(crate) fn add_entry_to_feed(
                     _ => "".to_string(),
                 },
             },
-            email: match &from.address {
-                Some(e) => Some(e.to_string()),
-                _ => None,
-            },
+            email: from.address.as_ref().map(|e| e.to_string()),
             uri: None,
         },
-        title: parsed
-            .get_subject()
-            .expect("Expected a subject")
-            .to_string(),
+        title: parsed.subject().expect("Expected a subject").to_string(),
         content: Some(processed_html.clone()),
         id: url.clone(),
-        published: Utc.timestamp(date.to_timestamp(), 0), //(format!("{}{}", &date.to_iso8601(), "+00:00").as_str()).`unwrap(),
+        published: Utc.timestamp_opt(date.to_timestamp(), 0).unwrap(),
         url: match include_html {
             true => url,
             false => "".to_string(),
         },
     }
     .into();
-    entry.set_updated(Utc.timestamp(date.to_timestamp(), 0));
+    entry.set_updated(Utc.timestamp_opt(date.to_timestamp(), 0).unwrap());
     feed.entries.push(entry);
 }
 
-pub(crate) fn build_atom_feed(hostname: &String) -> Feed {
+pub(crate) fn build_atom_feed(hostname: &String, feed_file: &str) -> Feed {
+    let feed_url = format!("https://{}/{}", hostname, feed_file);
     FeedBuilder::default()
         .title("JJKiers Newsletters")
-        .id(format!("https://{}/feed.atom", hostname))
+        .id(&feed_url)
         .link(
             LinkBuilder::default()
                 .href(format!("https://{}/", hostname))
-                .rel("alternate")
+                .rel("alternate".to_string())
                 .build(),
         )
         .link(
             LinkBuilder::default()
-                .href(format!("https://{}/feed.atom", hostname))
-                .rel("self")
+                .href(&feed_url)
+                .rel("self".to_string())
                 .build(),
         )
         .generator(Generator {
@@ -81,6 +77,19 @@ pub(crate) fn build_atom_feed(hostname: &String) -> Feed {
         .build()
 }
 
+pub(crate) fn write_feed<W: std::io::Write>(
+    feed: Feed,
+    mut out: W,
+) -> Result<W, atom_syndication::Error> {
+    let _ = writeln!(out, r#"<?xml version="1.0"?>"#);
+    let _ = writeln!(out, r#"<?xml-stylesheet href="feed.xsl" type="text/xsl"?>"#);
+    let config = WriteConfig {
+        write_document_declaration: false,
+        ..Default::default()
+    };
+    feed.write_with_config(out, config)
+}
+
 //#[derive(Serialize, Deserialize, Debug)]
 pub(crate) struct Newsletter {
     id: String,
@@ -104,15 +113,15 @@ impl From<Newsletter> for Entry {
 
         eb.title(post.title)
             .id(post.id)
-            .published(Some(post.published.clone().into()))
-            .author(post.author.into())
+            .published(Some(post.published.into()))
+            .author(post.author)
             .content(content);
 
         if post.url.len() > 1 {
             eb.link(
                 LinkBuilder::default()
                     .href(post.url)
-                    .rel("alternate")
+                    .rel("alternate".to_string())
                     .build(),
             );
         }

src/main.rs

@@ -1,4 +1,7 @@
+#[warn(missing_docs)]
+#[doc = include_str!("../README.md")]
 mod cli;
+mod command;
 mod feed;
 mod message;
 mod message_reader;
@@ -10,13 +13,16 @@ use message_reader::{DataDirectoryMessageReader, EmailReader, ImapReader};
 use sha2::{Digest, Sha256};
 use std::{
     error::Error,
-    fs::{File, OpenOptions},
+    fs::OpenOptions,
     io::Write,
     path::{Path, PathBuf},
 };
 
 pub(crate) use message::Message;
 
+const INDEX_HTML: &str = include_str!("../resources/index.html");
+const FEED_STYLESHEET: &str = include_str!("../resources/feed.xsl");
+
 fn main() -> Result<(), Box<dyn Error>> {
     let cli = cli::Cli::parse();
 
@@ -35,7 +41,12 @@ fn main() -> Result<(), Box<dyn Error>> {
             username.to_owned(),
             password.to_owned(),
         ),
-        cli::Command::BuildFeed { filename , hostname, include_html } => build_feed(&filename, hostname.to_owned(), *include_html),
+        cli::Command::BuildFeed {
+            filename,
+            hostname,
+            include_html,
+        } => build_feed(filename, hostname, *include_html),
+        cli::Command::Update => command::update::self_update(),
         _ => unimplemented!("This method is not yet implemented."),
     };
 
@@ -50,7 +61,11 @@ fn create_directory<P: AsRef<Path>>(dir: P) -> Result<(), std::io::Error> {
     Ok(())
 }
 
-fn build_feed(filename: &PathBuf, hostname: String, include_html: bool) -> Result<(), Box<dyn Error>> {
+fn build_feed(
+    filename: &PathBuf,
+    hostname: &String,
+    include_html: bool,
+) -> Result<(), Box<dyn Error>> {
     let dir = filename.parent().ok_or(format!(
         "Could not get parent directory of {}",
         filename.display()
@@ -64,45 +79,54 @@ fn build_feed(filename: &PathBuf, hostname: String, include_html: bool) -> Resul
 
     create_directory(dir)?;
 
-    let mut feed = feed::build_atom_feed(&hostname);
+    let feed_file = filename
+        .file_name()
+        .expect("Feed path should have a file name")
+        .to_str()
+        .expect("Feed path should be printable.");
 
-    let mut reader = DataDirectoryMessageReader::new((&Path::new("data")).to_path_buf());
+    let mut feed = feed::build_atom_feed(&hostname, feed_file);
+
+    let mut reader = DataDirectoryMessageReader::new(Path::new("data").to_path_buf());
 
     for msg in reader.read_rfc822_messages() {
         let parsed = msg.get_parsed().expect("A parsed messsage.");
 
-        let date = parsed.get_date().ok_or(format!(
+        let date = parsed.date().ok_or(format!(
             "Could not get the date of message {}",
             msg.get_uid()
         ))?;
 
-        let subject = match parsed.get_subject() {
-            Some(subject) => subject,
-            None => "No subject",
-        };
+        let subject = parsed.subject().unwrap_or("No subject");
 
         println!(
             "Processing message {} from {} with subject {}",
             msg.get_uid(),
-            date.to_string(),
+            date,
             subject
         );
 
-        let html_body = parsed.get_html_body(0).expect("Could not read html body");
+        let html_body = parsed.body_html(0).expect("Could not read html body");
         let processed_html = process_html(&html_body).expect("Could not process the HTML");
 
         if include_html {
-            let path : PathBuf = [dir, Path::new(&get_path(&parsed, &msg))].iter().collect();
+            let path: PathBuf = [dir, Path::new(&get_path(&parsed, &msg))].iter().collect();
             write_file(&path, processed_html.as_bytes())?;
         }
 
         feed::add_entry_to_feed(&mut feed, &msg, &processed_html, &hostname, include_html);
     }
 
-    if feed.entries.len() > 0 {
+    if !feed.entries.is_empty() {
         feed.set_updated(Utc::now());
         println!("Writing feed to {}", filename.display());
-        let _ = feed.write_to(File::create(filename).unwrap());
+
+        feed::write_feed(feed, open_file(filename).unwrap())?;
+        write_file(dir.join("feed.xsl"), FEED_STYLESHEET)?;
+        write_file(
+            dir.join("index.html"),
+            INDEX_HTML.replace("{FEED}", feed_file),
+        )?;
     }
 
     println!("Finished building the feed.");
@@ -121,12 +145,7 @@ fn fetch_from_imap(
 
     print!("Getting mail from {} for mailbox {}", server, username);
 
-    let mut reader = ImapReader::new(
-        String::from(server),
-        port,
-        String::from(username),
-        String::from(password),
-    );
+    let mut reader = ImapReader::new(server, port, username, password);
 
     for msg in reader.read_rfc822_messages() {
         let parsed = msg.get_parsed().ok_or(format!(
@@ -134,20 +153,17 @@ fn fetch_from_imap(
             msg.get_uid()
         ))?;
 
-        let date = parsed.get_date().ok_or(format!(
+        let date = parsed.date().ok_or(format!(
             "Could not get the date of message {}",
             msg.get_uid()
         ))?;
 
-        let subject = match parsed.get_subject() {
-            Some(subject) => subject,
-            None => "No subject",
-        };
+        let subject = parsed.subject().unwrap_or("No subject");
 
         println!(
             "Processing message {} from {} with subject {}",
             msg.get_uid(),
-            date.to_string(),
+            date,
             subject
         );
 
@@ -167,35 +183,40 @@ fn fetch_from_imap(
     Ok(())
 }
 
-
-
 fn get_path(parsed: &ParsedMessage, msg: &Message) -> String {
-    let date = parsed.get_date().expect("Could not extract date");
+    let date = parsed.date().expect("Could not extract date");
     let date_str = format!(
         "{:04}{:02}{:02}{:02}{:02}{:02}",
         &date.year, &date.month, &date.day, &date.hour, &date.minute, &date.second
     );
 
     let hash = base16ct::lower::encode_string(&Sha256::digest(
-        &parsed.get_html_body(0).expect("Expected a body").as_bytes(),
+        parsed.body_html(0).expect("Expected a body").as_bytes(),
     ));
 
-    let uid: i32 = msg.get_uid()
+    let uid: i32 = msg
+        .get_uid()
         .parse()
-        .expect(&format!("Could not convert message id {} to an i32.", msg.get_uid()));
+        .unwrap_or_else(|_| panic!("Could not convert message id {} to an i32.", msg.get_uid()));
 
-    format!("{:05}_{}_{}.html", uid, date_str, &hash).to_owned()
+    format!("{:05}_{}_{}.html", uid, date_str, &hash)
 }
 
 fn process_html(input: &str) -> Result<String, ()> {
     Ok(input.replace("src", "data-source"))
 }
 
-fn write_file(html_path: &PathBuf, data: &[u8]) -> Result<(), std::io::Error> {
+fn open_file<P: Into<PathBuf>>(path: P) -> std::io::Result<std::fs::File> {
     OpenOptions::new()
         .write(true)
+        .truncate(true)
         .create(true)
-        .open(&html_path)
-        .expect(format!("Could not open file '{}' for writing", &html_path.display()).as_str())
-        .write_all(data)
-}
+        .open(path.into())
+}
+
+fn write_file<P: Into<PathBuf>, D: AsRef<[u8]>>(path: P, data: D) -> Result<(), std::io::Error> {
+    let path: PathBuf = path.into();
+    open_file(path.clone())
+        .unwrap_or_else(|_| panic!("Could not open file '{}' for writing", &path.display()))
+        .write_all(data.as_ref())
+}

src/message.rs

@@ -21,4 +21,4 @@ impl Message {
     pub fn get_data(&self) -> &Vec<u8> {
         &self.data
     }
-}
+}

src/message_reader.rs

@@ -44,7 +44,7 @@ impl EmailReader for DataDirectoryMessageReader {
                 Some(ext) => ext == "eml",
                 None => false,
             })
-            .map(|i| {
+            .filter_map(|i| {
                 let uid = i
                     .path()
                     .file_stem()
@@ -52,9 +52,9 @@ impl EmailReader for DataDirectoryMessageReader {
                     .to_owned()
                     .into_string()
                     .expect("Could not convert filename to string.")
-                    .split("_")
+                    .split('_')
                     .collect::<Vec<&str>>()[0]
-                    .trim_start_matches("0")
+                    .trim_start_matches('0')
                     .to_string();
 
                 if let Ok(data) = std::fs::read(i.path()) {
@@ -63,8 +63,6 @@ impl EmailReader for DataDirectoryMessageReader {
                     None
                 }
             })
-            .filter(|i| i.is_some())
-            .map(|i| i.unwrap())
             .map(|i| Message::new(i.0, i.1));
 
         let iter = items.collect::<Vec<Message>>().into_iter();