refactor!(download): use builder pattern

rocks-bin/src/download.rs

@@ -2,9 +2,9 @@ use clap::Args;
 use eyre::Result;
 use rocks_lib::{
     config::Config,
+    operations,
     package::PackageReq,
     progress::{MultiProgress, Progress},
-    remote_package_db::RemotePackageDB,
 };
 
 #[derive(Args)]
@@ -13,13 +13,12 @@ pub struct Download {
 }
 
 pub async fn download(dl_data: Download, config: Config) -> Result<()> {
-    let package_db = RemotePackageDB::from_config(&config).await?;
     let progress = MultiProgress::new();
     let bar = Progress::Progress(progress.new_bar());
 
-    let rock =
-        rocks_lib::operations::download_to_file(&dl_data.package_req, None, &package_db, &bar)
-            .await?;
+    let rock = operations::Download::new(&dl_data.package_req, &config, &bar)
+        .download_src_rock_to_file(None)
+        .await?;
 
     bar.map(|b| {
         b.finish_with_message(format!(

rocks-bin/src/fetch.rs

@@ -3,8 +3,8 @@ use std::path::PathBuf;
 use eyre::Result;
 use rocks_lib::{
     config::Config,
+    operations::Download,
     progress::{MultiProgress, Progress},
-    remote_package_db::RemotePackageDB,
 };
 
 use crate::unpack::UnpackRemote;
@@ -13,9 +13,10 @@ pub async fn fetch_remote(data: UnpackRemote, config: Config) -> Result<()> {
     let package_req = data.package_req;
     let progress = MultiProgress::new();
     let bar = Progress::Progress(progress.new_bar());
-    let package_db = RemotePackageDB::from_config(&config).await?;
-    let rockspec =
-        rocks_lib::operations::download_rockspec(&package_req, &package_db, &bar).await?;
+
+    let rockspec = Download::new(&package_req, &config, &bar)
+        .download_rockspec()
+        .await?;
 
     let destination = data
         .path

rocks-bin/src/info.rs

@@ -2,10 +2,9 @@ use clap::Args;
 use eyre::Result;
 use rocks_lib::{
     config::{Config, LuaVersion},
-    operations::download_rockspec,
+    operations::Download,
     package::PackageReq,
     progress::{MultiProgress, Progress},
-    remote_package_db::RemotePackageDB,
     tree::Tree,
 };
 
@@ -17,12 +16,13 @@ pub struct Info {
 pub async fn info(data: Info, config: Config) -> Result<()> {
     // TODO(vhyrro): Add `Tree::from(&Config)`
     let tree = Tree::new(config.tree().clone(), LuaVersion::from(&config)?)?;
-    let package_db = RemotePackageDB::from_config(&config).await?;
 
     let progress = MultiProgress::new();
     let bar = Progress::Progress(progress.new_bar());
 
-    let rockspec = download_rockspec(&data.package, &package_db, &bar).await?;
+    let rockspec = Download::new(&data.package, &config, &bar)
+        .download_rockspec()
+        .await?;
 
     bar.map(|b| b.finish_and_clear());
 

rocks-bin/src/unpack.rs

@@ -4,9 +4,9 @@ use clap::Args;
 use eyre::Result;
 use rocks_lib::{
     config::Config,
+    operations,
     package::PackageReq,
     progress::{MultiProgress, Progress},
-    remote_package_db::RemotePackageDB,
 };
 
 #[derive(Args)]
@@ -49,10 +49,10 @@ and type `rocks make` to build.",
 
 pub async fn unpack_remote(data: UnpackRemote, config: Config) -> Result<()> {
     let package_req = data.package_req;
-    let package_db = RemotePackageDB::from_config(&config).await?;
     let progress = MultiProgress::new();
     let bar = Progress::Progress(progress.new_bar());
-    let rock = rocks_lib::operations::search_and_download_src_rock(&package_req, &package_db, &bar)
+    let rock = operations::Download::new(&package_req, &config, &bar)
+        .search_and_download_src_rock()
         .await?;
     let cursor = Cursor::new(rock.bytes);
 

rocks-lib/src/operations/download.rs

@@ -4,12 +4,85 @@ use bytes::Bytes;
 use thiserror::Error;
 
 use crate::{
+    config::Config,
     package::{PackageName, PackageReq, PackageVersion, RemotePackage},
     progress::{Progress, ProgressBar},
-    remote_package_db::{RemotePackageDB, SearchError},
+    remote_package_db::{RemotePackageDB, RemotePackageDBError, SearchError},
     rockspec::{Rockspec, RockspecError},
 };
 
+pub struct Download<'a> {
+    package_req: &'a PackageReq,
+    package_db: Option<RemotePackageDB>,
+    config: &'a Config,
+    progress: &'a Progress<ProgressBar>,
+}
+
+/// Builder for a rock downloader.
+impl<'a> Download<'a> {
+    /// Construct a new `.src.rock` downloader.
+    pub fn new(
+        package_req: &'a PackageReq,
+        config: &'a Config,
+        progress: &'a Progress<ProgressBar>,
+    ) -> Self {
+        Self {
+            package_req,
+            package_db: None,
+            config,
+            progress,
+        }
+    }
+
+    /// Sets the package database to use for searching for packages.
+    /// Instantiated from the config if not set.
+    pub fn package_db(self, package_db: RemotePackageDB) -> Self {
+        Self {
+            package_db: Some(package_db),
+            ..self
+        }
+    }
+
+    /// Download the package's Rockspec.
+    pub async fn download_rockspec(self) -> Result<Rockspec, SearchAndDownloadError> {
+        let package_db = match self.package_db {
+            Some(db) => db,
+            None => RemotePackageDB::from_config(self.config).await?,
+        };
+        download_rockspec(self.package_req, &package_db, self.progress).await
+    }
+
+    /// Download a `.src.rock` to a file.
+    /// `destination_dir` defaults to the current working directory if not set.
+    pub async fn download_src_rock_to_file(
+        self,
+        destination_dir: Option<PathBuf>,
+    ) -> Result<DownloadedSrcRock, SearchAndDownloadError> {
+        let package_db = match self.package_db {
+            Some(db) => db,
+            None => RemotePackageDB::from_config(self.config).await?,
+        };
+        download_src_rock_to_file(
+            self.package_req,
+            destination_dir,
+            &package_db,
+            self.progress,
+        )
+        .await
+    }
+
+    /// Search for a `.src.rock` and download it to memory.
+    pub async fn search_and_download_src_rock(
+        self,
+    ) -> Result<DownloadedSrcRockBytes, SearchAndDownloadError> {
+        let package_db = match self.package_db {
+            Some(db) => db,
+            None => RemotePackageDB::from_config(self.config).await?,
+        };
+        search_and_download_src_rock(self.package_req, &package_db, self.progress).await
+    }
+}
+
 pub struct DownloadedSrcRockBytes {
     pub name: PackageName,
     pub version: PackageVersion,
@@ -29,9 +102,11 @@ pub enum DownloadRockspecError {
     Request(#[from] reqwest::Error),
     #[error("failed to convert rockspec response: {0}")]
     ResponseConversion(#[from] FromUtf8Error),
+    #[error("error initialising remote package DB: {0}")]
+    RemotePackageDB(#[from] RemotePackageDBError),
 }
 
-pub async fn download_rockspec(
+async fn download_rockspec(
     package_req: &PackageReq,
     package_db: &RemotePackageDB,
     progress: &Progress<ProgressBar>,
@@ -55,9 +130,11 @@ pub enum SearchAndDownloadError {
     Utf8(#[from] FromUtf8Error),
     #[error(transparent)]
     Rockspec(#[from] RockspecError),
+    #[error("error initialising remote package DB: {0}")]
+    RemotePackageDB(#[from] RemotePackageDBError),
 }
 
-pub async fn search_and_download_src_rock(
+async fn search_and_download_src_rock(
     package_req: &PackageReq,
     package_db: &RemotePackageDB,
     progress: &Progress<ProgressBar>,
@@ -79,7 +156,7 @@ pub(crate) async fn download_src_rock(
     download_src_rock_impl(remote_package).await
 }
 
-pub async fn download_to_file(
+async fn download_src_rock_to_file(
     package_req: &PackageReq,
     destination_dir: Option<PathBuf>,
     package_db: &RemotePackageDB,

rocks-lib/src/operations/resolve.rs

@@ -16,7 +16,7 @@ use crate::{
     rockspec::Rockspec,
 };
 
-use super::{download_rockspec, SearchAndDownloadError};
+use super::{Download, SearchAndDownloadError};
 
 #[derive(Clone, Debug)]
 pub(crate) struct PackageInstallSpec {
@@ -52,9 +52,9 @@ pub(crate) async fn get_all_dependencies(
                 tokio::spawn(async move {
                     let bar = progress.map(|p| p.new_bar());
 
-                    let rockspec = download_rockspec(&package, &package_db, &bar)
-                        .await
-                        .unwrap();
+                    let rockspec = Download::new(&package, &config, &bar)
+                        .download_rockspec()
+                        .await?;
 
                     let constraint =
                         if *package.version_req() == PackageVersionReq::SemVer(VersionReq::STAR) {