Replace color-eyre usage with our own error types using thiserror.

source/error.rs

@@ -0,0 +1,13 @@
+//! All error types.
+
+use thiserror::Error;
+
+/// Errors that can happen while parsing.
+#[derive(Debug, Error)]
+pub enum ParseError {
+  /// The error for when HTML text or attributes are missing and they should be
+  /// present. This could be user error by having an edge case not covered, or
+  /// Tildes could have been updated and the HTML changed in the meantime.
+  #[error("Missing expected HTML values")]
+  MissingExpectedHtml,
+}

source/from_str.rs

@@ -2,9 +2,9 @@
 
 use std::str::FromStr;
 
-use {color_eyre::eyre::Error, duplicate::duplicate_item, scraper::Html};
+use {duplicate::duplicate_item, scraper::Html};
 
-use crate::{Group, GroupList};
+use crate::{Group, GroupList, ParseError};
 
 #[duplicate_item(
   _Struct;
@@ -12,7 +12,7 @@ use crate::{Group, GroupList};
   [GroupList];
 )]
 impl FromStr for _Struct {
-  type Err = Error;
+  type Err = ParseError;
 
   fn from_str(s: &str) -> Result<Self, Self::Err> {
     let html = Html::parse_document(s);

source/group.rs

@@ -1,6 +1,6 @@
 //! Parsing for `/~<group>`.
 
-use {color_eyre::Result, scraper::Html};
+use scraper::Html;
 
 use crate::{
   regexes::GROUP_SUBSCRIBERS_RE,
@@ -11,6 +11,7 @@ use crate::{
   utilities::{
     extract_anchor_values, parse_regex_match, select_first_element_text,
   },
+  ParseError,
 };
 
 /// A group's information.
@@ -44,37 +45,37 @@ pub struct GroupWikiLink {
 
 impl Group {
   /// Parses a [`Group`] from a [`scraper::Html`] tree.
-  pub fn from_html(html: &Html) -> Result<Self> {
+  pub fn from_html(html: &Html) -> Result<Self, ParseError> {
     let description =
       select_first_element_text(html.root_element(), &GROUP_DESCRIPTION);
 
-    let name =
-      select_first_element_text(html.root_element(), &GROUP_NAME).unwrap();
+    let name = select_first_element_text(html.root_element(), &GROUP_NAME)
+      .ok_or(ParseError::MissingExpectedHtml)?;
 
     let subscribers = parse_regex_match(
       GROUP_SUBSCRIBERS_RE
         .captures_iter(
           &select_first_element_text(html.root_element(), &GROUP_SUBSCRIBERS)
-            .unwrap(),
+            .ok_or(ParseError::MissingExpectedHtml)?,
         )
         .next()
-        .unwrap()
+        .ok_or(ParseError::MissingExpectedHtml)?
         .name("count"),
     )
-    .unwrap();
+    .ok_or(ParseError::MissingExpectedHtml)?;
 
     let sub_groups = html
       .select(&GROUP_SUB_GROUP_LINKS)
-      .map(|element| extract_anchor_values(element).0)
-      .collect();
+      .map(|element| Ok(extract_anchor_values(element)?.0))
+      .collect::<Result<_, _>>()?;
 
     let wiki_links = html
       .select(&GROUP_WIKI_LINKS)
       .map(|element| {
-        let (name, url) = extract_anchor_values(element);
-        GroupWikiLink { name, url }
+        let (name, url) = extract_anchor_values(element)?;
+        Ok(GroupWikiLink { name, url })
       })
-      .collect();
+      .collect::<Result<_, _>>()?;
 
     Ok(Self {
       description,

source/group_list.rs

@@ -1,11 +1,12 @@
 //! Parsing for [`/groups`](https://tildes.net/groups).
 
-use {color_eyre::Result, scraper::Html};
+use scraper::Html;
 
 use crate::{
   regexes::{DUPLICATE_WHITESPACE_RE, GROUP_LIST_ACTIVITY_RE},
   selectors::{GROUP_LINK, GROUP_LIST_ACTIVITY, GROUP_LIST_DESCRIPTION},
   utilities::{parse_regex_match, select_first_element_text, selector},
+  ParseError,
 };
 
 /// The group list from the [`/groups`](https://tildes.net/groups) page.
@@ -34,7 +35,7 @@ pub struct GroupListSummary {
 
 impl GroupList {
   /// Parses a [`GroupList`] from a [`scraper::Html`] tree.
-  pub fn from_html(html: &Html) -> Result<Self> {
+  pub fn from_html(html: &Html) -> Result<Self, ParseError> {
     let summaries = html
       .select(&selector(".group-list li"))
       .map(|parent| {
@@ -54,17 +55,18 @@ impl GroupList {
             .unwrap_or_default()
         };
 
-        GroupListSummary {
+        Ok(GroupListSummary {
           comment_activity: activity_counts.0,
           description: select_first_element_text(
             parent,
             &GROUP_LIST_DESCRIPTION,
           ),
-          name: select_first_element_text(parent, &GROUP_LINK).unwrap(),
+          name: select_first_element_text(parent, &GROUP_LINK)
+            .ok_or(ParseError::MissingExpectedHtml)?,
           topic_activity: activity_counts.1,
-        }
+        })
       })
-      .collect();
+      .collect::<Result<_, _>>()?;
 
     Ok(Self { summaries })
   }

source/lib.rs

@@ -24,11 +24,13 @@ pub mod regexes;
 pub mod selectors;
 pub mod utilities;
 
+pub(crate) mod error;
 pub(crate) mod from_str;
 pub(crate) mod group;
 pub(crate) mod group_list;
 
 pub use {
+  error::*,
   group::{Group, GroupWikiLink},
   group_list::{GroupList, GroupListSummary},
 };

source/utilities.rs

@@ -7,17 +7,23 @@ use {
   scraper::{ElementRef, Selector},
 };
 
-use crate::regexes::DUPLICATE_WHITESPACE_RE;
+use crate::{regexes::DUPLICATE_WHITESPACE_RE, ParseError};
 
 /// Shorthand to extract the text and `href` values from an anchor element.
-pub fn extract_anchor_values(anchor: ElementRef) -> (String, String) {
+pub fn extract_anchor_values(
+  anchor: ElementRef,
+) -> Result<(String, String), ParseError> {
   let name = DUPLICATE_WHITESPACE_RE
     .replace_all(&anchor.text().collect::<String>(), " ")
     .trim()
     .to_string();
-  let href = anchor.value().attr("href").unwrap().to_string();
+  let href = anchor
+    .value()
+    .attr("href")
+    .ok_or(ParseError::MissingExpectedHtml)?
+    .to_string();
 
-  (name, href)
+  Ok((name, href))
 }
 
 /// Shorthand to parse a [`regex::Match`] with [`std::str::FromStr`].