fix version matching, now works with semver

src/drivers.rs

@@ -2,45 +2,90 @@
 use std::time::Duration;
 use std::path::{Path, PathBuf};
 
-use log::{debug, error};
+use log::{debug};
+use anyhow::{Context, anyhow};
+use semver::{Version, VersionReq};
 
 use crates_io_api::AsyncClient;
 
 use crate::PkgFmt;
 use crate::helpers::*;
 
+fn find_version<'a, V: Iterator<Item=&'a str>>(requirement: &str, version_iter: V) -> Result<String, anyhow::Error> {
+    // Parse version requirement
+    let version_req = VersionReq::parse(requirement)?;
+
+    // Filter for matching versions
+    let mut filtered: Vec<_> = version_iter.filter(|v| {
+        // Remove leading `v` for git tags
+        let ver_str = match v.strip_prefix("s") {
+            Some(v) => v,
+            None => v,
+        };
+
+        // Parse out version
+        let ver = match Version::parse(ver_str) {
+            Ok(sv) => sv,
+            Err(_) => return false,
+        };
+
+        debug!("Version: {:?}", ver);
+
+        // Filter by version match
+        version_req.matches(&ver)
+    }).collect();
+
+    // Sort by highest matching version
+    filtered.sort_by(|a, b| {
+        let a = Version::parse(a).unwrap();
+        let b = Version::parse(b).unwrap();
+
+        b.partial_cmp(&a).unwrap()
+    });
+
+    debug!("Filtered: {:?}", filtered);
+
+    // Return highest version
+    match filtered.get(0) {
+        Some(v) => Ok(v.to_string()),
+        None => Err(anyhow!("No matching version for requirement: '{}'", version_req))
+    }
+}
+
 /// Fetch a crate by name and version from crates.io
-pub async fn fetch_crate_cratesio(name: &str, version: Option<&str>, temp_dir: &Path) -> Result<PathBuf, anyhow::Error> {
-    // Build crates.io api client and fetch info
-    let api_client = AsyncClient::new("cargo-binstall (https://github.com/ryankurte/cargo-binstall)", Duration::from_millis(100))?;
+pub async fn fetch_crate_cratesio(name: &str, version_req: &str, temp_dir: &Path) -> Result<PathBuf, anyhow::Error> {
 
-    debug!("Fetching information for crate: '{}'", name);
+    // Fetch / update index
+    debug!("Updating crates.io index");
+    let index = crates_index::Index::new_cargo_default();
+    index.retrieve_or_update()?;
 
-    // Fetch overall crate info
-    let info = match api_client.get_crate(name.as_ref()).await {
-        Ok(i) => i,
-        Err(e) => {
-            error!("Error fetching information for crate {}: {}", name, e);
-            return Err(e.into())
+    // Lookup crate in index
+    debug!("Looking up crate information");
+    let base_info = match index.crate_(name) {
+        Some(i) => i,
+        None => {
+            return Err(anyhow::anyhow!("Error fetching information for crate {}", name));
         }
     };
 
-    // Use specified or latest version
-    let version_num = match version {
-        Some(v) => v.to_string(),
-        None => info.crate_data.max_version,
-    };
+    // Locate matching version
+    let version_iter = base_info.versions().iter().map(|v| v.version() );
+    let version_name = find_version(version_req, version_iter)?;
+    
+    // Build crates.io api client
+    let api_client = AsyncClient::new("cargo-binstall (https://github.com/ryankurte/cargo-binstall)", Duration::from_millis(100))?;
 
-    // Fetch crates.io information for the specified version
-    // Note it is not viable to use a semver match here as crates.io
-    // appears to elide alpha and yanked versions in the generic response...
-    let versions = info.versions.clone();
-    let version = match versions.iter().find(|v| v.num == version_num) {
+    // Fetch online crate information
+    let crate_info = api_client.get_crate(name.as_ref()).await
+        .context("Error fetching crate information")?;
+
+    // Fetch information for the filtered version
+    let version = match crate_info.versions.iter().find(|v| v.num == version_name) {
         Some(v) => v,
         None => {
-            error!("No crates.io information found for crate: '{}' version: '{}'", 
-                    name, version_num);
-            return Err(anyhow::anyhow!("No crate information found"));
+            return Err(anyhow::anyhow!("No information found for crate: '{}' version: '{}'", 
+                    name, version_name));
         }
     };
 
@@ -58,7 +103,7 @@ pub async fn fetch_crate_cratesio(name: &str, version: Option<&str>, temp_dir: &
     // Decompress downloaded tgz
     debug!("Decompressing crate archive");
     extract(&tgz_path, PkgFmt::Tgz, &temp_dir)?;
-    let crate_path = temp_dir.join(format!("{}-{}", name, version_num));
+    let crate_path = temp_dir.join(format!("{}-{}", name, version_name));
 
     // Return crate directory
     Ok(crate_path)