Fix bug where if a modpack had no files available the program would crash (#508)

Author: theRookieCoder

libium/src/add.rs

@@ -254,7 +254,7 @@ pub async fn add(
 
     for (project, pin) in cf_projects.into_iter().zip(cf_file_ids) {
         if let Some(i) = cf_project_ids.iter().position(|&id| id == project.id) {
-            cf_project_ids.swap_remove(i);
+            cf_project_ids.remove(i);
         }
 
         let res = 'cf_check: {
@@ -359,7 +359,7 @@ pub async fn add(
             .iter()
             .position(|id| id == &project.id || project.slug.eq_ignore_ascii_case(id))
         {
-            mr_project_ids.swap_remove(i);
+            mr_project_ids.remove(i);
         }
 
         let res = 'mr_check: {

libium/src/upgrade/mod.rs

@@ -92,7 +92,7 @@ pub fn try_from_cf_file(
             download_url: file
                 .download_url
                 .ok_or(DistributionDeniedError(file.mod_id, file.id))?,
-            output: file.file_name.as_str().into(),
+            output: file.file_name.into(),
             length: file.file_length as usize,
             dependencies: file
                 .dependencies

libium/src/upgrade/modpack_downloadable.rs

@@ -20,6 +20,8 @@ pub enum Error {
     ReqwestError(#[from] reqwest::Error),
     DownloadError(#[from] super::Error),
     IOError(#[from] std::io::Error),
+    #[error("The modpack has no files available")]
+    NoFilesAvailable,
 }
 type Result<T> = std::result::Result<T, Error>;
 
@@ -30,12 +32,22 @@ impl ModpackIdentifier {
         update: impl Fn(usize) + Send,
     ) -> Result<PathBuf> {
         let (_, download_data) = match self {
-            ModpackIdentifier::CurseForgeModpack(id) => {
-                try_from_cf_file(CURSEFORGE_API.get_mod_files(*id).await?.swap_remove(0))?
-            }
-            ModpackIdentifier::ModrinthModpack(id) => {
-                from_mr_version(MODRINTH_API.version_list(id).await?.swap_remove(0))
-            }
+            ModpackIdentifier::CurseForgeModpack(id) => try_from_cf_file(
+                CURSEFORGE_API
+                    .get_mod_files(*id)
+                    .await?
+                    .into_iter()
+                    .nth(0)
+                    .ok_or(Error::NoFilesAvailable)?,
+            )?,
+            ModpackIdentifier::ModrinthModpack(id) => from_mr_version(
+                MODRINTH_API
+                    .version_list(id)
+                    .await?
+                    .into_iter()
+                    .nth(0)
+                    .ok_or(Error::NoFilesAvailable)?,
+            ),
         };
 
         let cache_dir = PROJECT_DIRS.cache_dir().join("downloaded");

src/download.rs

@@ -36,7 +36,7 @@ pub async fn clean(
                 dupes.len(),
                 dupes
                     .into_iter()
-                    .map(|i| to_download.swap_remove(i).filename())
+                    .map(|i| to_download.remove(i).filename())
                     .display(", ")
             )
             .yellow()
@@ -57,11 +57,11 @@ pub async fn clean(
                 .position(|thing| filename == thing.filename())
             {
                 // Don't download it
-                to_download.swap_remove(index);
+                to_download.remove(index);
             // Likewise, if it is already installed
             } else if let Some(index) = to_install.iter().position(|thing| filename == thing.0) {
                 // Don't install it
-                to_install.swap_remove(index);
+                to_install.remove(index);
             // Or else, move the file to `directory`/.old
             // If the file is a `.part` file or if the move failed, delete the file
             } else if filename.ends_with("part")

src/subcommands/remove.rs

@@ -75,7 +75,7 @@ pub fn remove(profile: &mut Profile, to_remove: Vec<String>) -> Result<()> {
 
     let mut removed = Vec::new();
     for index in indices_to_remove {
-        removed.push(profile.mods.swap_remove(index).name);
+        removed.push(profile.mods.remove(index).name);
     }
 
     if !removed.is_empty() {