Fix ArtifactId::path (paritytech#3027)

* issue with ArtifactId::path

* fix artifacts path

* Wrap an overly long line

Co-authored-by: Sergei Shulepov <s.pepyakin@gmail.com>

node/core/pvf/src/artifacts.rs

@@ -82,7 +82,7 @@ impl ArtifactId {
 
 	/// Returns the expected path to this artifact given the root of the cache.
 	pub fn path(&self, cache_path: &Path) -> PathBuf {
-		let file_name = format!("{}{}", Self::PREFIX, self.code_hash.to_string());
+		let file_name = format!("{}{:#x}", Self::PREFIX, self.code_hash);
 		cache_path.join(file_name)
 	}
 }
@@ -276,7 +276,10 @@ async fn scan_for_known_artifacts(
 
 #[cfg(test)]
 mod tests {
+	use async_std::path::Path;
 	use super::ArtifactId;
+	use sp_core::H256;
+	use std::str::FromStr;
 
 	#[test]
 	fn ensure_wasmtime_version() {
@@ -308,4 +311,15 @@ mod tests {
 			)),
 		);
 	}
+
+	#[test]
+	fn path() {
+		let path = Path::new("/test");
+		let hash = H256::from_str("1234567890123456789012345678901234567890123456789012345678901234").unwrap();
+
+		assert_eq!(
+			ArtifactId::new(hash).path(path).to_str(),
+			Some("/test/wasmtime_1_0x1234567890123456789012345678901234567890123456789012345678901234"),
+		);
+	}
 }