2 files changed, 120 insertions, 116 deletions

diff --git a/test_util/src/lib.rs b/test_util/src/lib.rs
index af4c814c4..bf81e01a6 100644
--- a/test_util/src/lib.rs
+++ b/test_util/src/lib.rs
@@ -14,7 +14,7 @@ use hyper::Request;
 use hyper::Response;
 use hyper::StatusCode;
 use lazy_static::lazy_static;
-use npm::custom_npm_cache;
+use npm::CUSTOM_NPM_PACKAGE_CACHE;
 use os_pipe::pipe;
 use pretty_assertions::assert_eq;
 use regex::Regex;
@@ -1009,19 +1009,18 @@ fn handle_custom_npm_registry_path(
     .split('/')
     .filter(|p| !p.is_empty())
     .collect::<Vec<_>>();
-  let cache = custom_npm_cache()?;
+  let cache = &CUSTOM_NPM_PACKAGE_CACHE;
   let package_name = format!("@denotest/{}", parts[0]);
   if parts.len() == 2 {
     if let Some(file_bytes) =
-      cache.tarball_bytes(&package_name, parts[1].trim_end_matches(".tgz"))
+      cache.tarball_bytes(&package_name, parts[1].trim_end_matches(".tgz"))?
     {
-      let file_resp = custom_headers("file.tgz", file_bytes.to_owned());
+      let file_resp = custom_headers("file.tgz", file_bytes);
       return Ok(Some(file_resp));
     }
   } else if parts.len() == 1 {
-    if let Some(registry_file) = cache.registry_file(&package_name) {
-      let file_resp =
-        custom_headers("registry.json", registry_file.as_bytes().to_vec());
+    if let Some(registry_file) = cache.registry_file(&package_name)? {
+      let file_resp = custom_headers("registry.json", registry_file);
       return Ok(Some(file_resp));
     }
   }
diff --git a/test_util/src/npm.rs b/test_util/src/npm.rs
index dd194facc..fad59e3b8 100644
--- a/test_util/src/npm.rs
+++ b/test_util/src/npm.rs
@@ -2,24 +2,17 @@ use std::collections::HashMap;
 use std::fs;
 
 use anyhow::Context;
+use anyhow::Result;
 use flate2::write::GzEncoder;
 use flate2::Compression;
 use once_cell::sync::Lazy;
+use parking_lot::Mutex;
 use tar::Builder;
 
 use crate::testdata_path;
 
-static CUSTOM_NPM_PACKAGE_CACHE: Lazy<Result<CustomNpmPackageCache, String>> =
-  Lazy::new(|| CustomNpmPackageCache::load().map_err(|e| e.to_string()));
-
-/// Get a reference to the custom npm cache which is lazily created.
-pub fn custom_npm_cache(
-) -> Result<&'static CustomNpmPackageCache, anyhow::Error> {
-  match &*CUSTOM_NPM_PACKAGE_CACHE {
-    Ok(cache) => Ok(cache),
-    Err(err) => Err(anyhow::anyhow!("{}", err)),
-  }
-}
+pub static CUSTOM_NPM_PACKAGE_CACHE: Lazy<CustomNpmPackageCache> =
+  Lazy::new(CustomNpmPackageCache::default);
 
 struct CustomNpmPackage {
   pub registry_file: String,
@@ -28,116 +21,128 @@ struct CustomNpmPackage {
 
 /// Creates tarballs and a registry json file for npm packages
 /// in the `testdata/npm/registry/@denotest` directory.
-pub struct CustomNpmPackageCache(HashMap<String, CustomNpmPackage>);
+#[derive(Default)]
+pub struct CustomNpmPackageCache(Mutex<HashMap<String, CustomNpmPackage>>);
 
 impl CustomNpmPackageCache {
-  pub fn load() -> Result<Self, anyhow::Error> {
-    use ring::digest::Context;
-    use ring::digest::SHA512;
-
-    // read all the packages in the @denotest folder
-    let custom_packages_path = testdata_path().join("npm/registry/@denotest");
-    let mut packages = HashMap::new();
-    for entry in fs::read_dir(&custom_packages_path)? {
-      let entry = entry?;
-      let file_type = entry.file_type()?;
-      if !file_type.is_dir() {
-        continue;
-      }
+  pub fn tarball_bytes(
+    &self,
+    name: &str,
+    version: &str,
+  ) -> Result<Option<Vec<u8>>> {
+    Ok(
+      self
+        .get_package_property(name, |p| p.tarballs.get(version).cloned())?
+        .flatten(),
+    )
+  }
 
-      // read all the package's versions
-      let mut tarballs = HashMap::new();
-      let package_folder_name = entry.file_name().to_string_lossy().to_string();
-      let package_name = format!("@denotest/{}", package_folder_name);
-      let package_folder = custom_packages_path.join(&package_folder_name);
-      let mut versions = serde_json::Map::new();
-      for entry in fs::read_dir(&package_folder)? {
-        let entry = entry?;
-        let file_type = entry.file_type()?;
-        if !file_type.is_dir() {
-          continue;
-        }
-        let version = entry.file_name().to_string_lossy().to_string();
-        let version_folder = package_folder.join(&version);
-
-        // create the tarball
-        let mut tarball_bytes = Vec::new();
-        {
-          let mut encoder =
-            GzEncoder::new(&mut tarball_bytes, Compression::default());
-          {
-            let mut builder = Builder::new(&mut encoder);
-            builder
-              .append_dir_all("package", &version_folder)
-              .with_context(|| {
-                format!(
-                  "Error adding tarball for directory: {}",
-                  version_folder.display()
-                )
-              })?;
-            builder.finish()?;
-          }
-          encoder.finish()?;
+  pub fn registry_file(&self, name: &str) -> Result<Option<Vec<u8>>> {
+    self.get_package_property(name, |p| p.registry_file.as_bytes().to_vec())
+  }
+
+  fn get_package_property<TResult>(
+    &self,
+    package_name: &str,
+    func: impl FnOnce(&CustomNpmPackage) -> TResult,
+  ) -> Result<Option<TResult>> {
+    // it's ok if multiple threads race here as they will do the same work twice
+    if !self.0.lock().contains_key(package_name) {
+      match get_npm_package(package_name)? {
+        Some(package) => {
+          self.0.lock().insert(package_name.to_string(), package);
         }
+        None => return Ok(None),
+      }
+    }
+    Ok(self.0.lock().get(package_name).map(func))
+  }
+}
+
+fn get_npm_package(package_name: &str) -> Result<Option<CustomNpmPackage>> {
+  use ring::digest::Context;
+  use ring::digest::SHA512;
+
+  let package_folder = testdata_path().join("npm/registry").join(package_name);
+  if !package_folder.exists() {
+    return Ok(None);
+  }
 
-        // get tarball hash
-        let mut hash_ctx = Context::new(&SHA512);
-        hash_ctx.update(&tarball_bytes);
-        let digest = hash_ctx.finish();
-        let tarball_checksum = base64::encode(digest.as_ref()).to_lowercase();
-
-        // create the registry file JSON for this version
-        let mut dist = serde_json::Map::new();
-        dist.insert(
-          "integrity".to_string(),
-          format!("sha512-{}", tarball_checksum).into(),
-        );
-        dist.insert("shasum".to_string(), "dummy-value".into());
-        dist.insert(
-          "tarball".to_string(),
-          format!(
-            "http://localhost:4545/npm/registry/{}/{}.tgz",
-            package_name, version
-          )
-          .into(),
-        );
-
-        tarballs.insert(version.clone(), tarball_bytes);
-        let package_json_path = version_folder.join("package.json");
-        let package_json_text = fs::read_to_string(&package_json_path)
+  // read all the package's versions
+  let mut tarballs = HashMap::new();
+  let mut versions = serde_json::Map::new();
+  for entry in fs::read_dir(&package_folder)? {
+    let entry = entry?;
+    let file_type = entry.file_type()?;
+    if !file_type.is_dir() {
+      continue;
+    }
+    let version = entry.file_name().to_string_lossy().to_string();
+    let version_folder = package_folder.join(&version);
+
+    // create the tarball
+    let mut tarball_bytes = Vec::new();
+    {
+      let mut encoder =
+        GzEncoder::new(&mut tarball_bytes, Compression::default());
+      {
+        let mut builder = Builder::new(&mut encoder);
+        builder
+          .append_dir_all("package", &version_folder)
           .with_context(|| {
             format!(
-              "Error reading package.json at {}",
-              package_json_path.display()
+              "Error adding tarball for directory: {}",
+              version_folder.display()
             )
           })?;
-        let mut version_info: serde_json::Map<String, serde_json::Value> =
-          serde_json::from_str(&package_json_text)?;
-        version_info.insert("dist".to_string(), dist.into());
-        versions.insert(version, version_info.into());
+        builder.finish()?;
       }
-
-      // create the registry file for this package
-      let mut registry_file = serde_json::Map::new();
-      registry_file.insert("name".to_string(), package_name.clone().into());
-      registry_file.insert("versions".to_string(), versions.into());
-      packages.insert(
-        package_name,
-        CustomNpmPackage {
-          registry_file: serde_json::to_string(&registry_file).unwrap(),
-          tarballs,
-        },
-      );
+      encoder.finish()?;
     }
 
-    Ok(Self(packages))
+    // get tarball hash
+    let mut hash_ctx = Context::new(&SHA512);
+    hash_ctx.update(&tarball_bytes);
+    let digest = hash_ctx.finish();
+    let tarball_checksum = base64::encode(digest.as_ref()).to_lowercase();
+
+    // create the registry file JSON for this version
+    let mut dist = serde_json::Map::new();
+    dist.insert(
+      "integrity".to_string(),
+      format!("sha512-{}", tarball_checksum).into(),
+    );
+    dist.insert("shasum".to_string(), "dummy-value".into());
+    dist.insert(
+      "tarball".to_string(),
+      format!(
+        "http://localhost:4545/npm/registry/{}/{}.tgz",
+        package_name, version
+      )
+      .into(),
+    );
+
+    tarballs.insert(version.clone(), tarball_bytes);
+    let package_json_path = version_folder.join("package.json");
+    let package_json_text = fs::read_to_string(&package_json_path)
+      .with_context(|| {
+        format!(
+          "Error reading package.json at {}",
+          package_json_path.display()
+        )
+      })?;
+    let mut version_info: serde_json::Map<String, serde_json::Value> =
+      serde_json::from_str(&package_json_text)?;
+    version_info.insert("dist".to_string(), dist.into());
+    versions.insert(version, version_info.into());
   }
 
-  pub fn tarball_bytes(&self, name: &str, version: &str) -> Option<&Vec<u8>> {
-    self.0.get(name).and_then(|p| p.tarballs.get(version))
-  }
-
-  pub fn registry_file(&self, name: &str) -> Option<&String> {
-    self.0.get(name).map(|p| &p.registry_file)
-  }
+  // create the registry file for this package
+  let mut registry_file = serde_json::Map::new();
+  registry_file.insert("name".to_string(), package_name.to_string().into());
+  registry_file.insert("versions".to_string(), versions.into());
+  Ok(Some(CustomNpmPackage {
+    registry_file: serde_json::to_string(&registry_file).unwrap(),
+    tarballs,
+  }))
 }