From 9ca4d8f618d89d5514792646ffa6707fcd79fc9c Mon Sep 17 00:00:00 2001
From: George Pollard <gpollard@microsoft.com>
Date: Wed, 5 Jul 2023 00:37:19 +0000
Subject: [PATCH] Simplify more

---
 src/agent/Cargo.lock                          |  7 ++++
 src/agent/onefuzz-task/Cargo.toml             |  1 +
 .../src/tasks/fuzz/libfuzzer/generic.rs       | 36 ++-----------------
 3 files changed, 11 insertions(+), 33 deletions(-)

diff --git a/src/agent/Cargo.lock b/src/agent/Cargo.lock
index c765c8edaba..58d13019e3a 100644
--- a/src/agent/Cargo.lock
+++ b/src/agent/Cargo.lock
@@ -420,6 +420,12 @@ version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "631ae5198c9be5e753e5cc215e1bd73c2b466a3565173db433f52bb9d3e66dba"
 
+[[package]]
+name = "cascade"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d499b43edbf784dd81e16f0395f5b4350a35b477da8a074251087adefc11cb52"
+
 [[package]]
 name = "cassowary"
 version = "0.3.0"
@@ -2292,6 +2298,7 @@ dependencies = [
  "azure_storage",
  "azure_storage_blobs",
  "backoff",
+ "cascade",
  "chrono",
  "clap",
  "cobertura",
diff --git a/src/agent/onefuzz-task/Cargo.toml b/src/agent/onefuzz-task/Cargo.toml
index 31bc99cc9a4..f6cf218d942 100644
--- a/src/agent/onefuzz-task/Cargo.toml
+++ b/src/agent/onefuzz-task/Cargo.toml
@@ -68,6 +68,7 @@ azure_storage_blobs = { version = "0.12", default-features = false, features = [
 ] }
 
 flexi_logger = "0.25"
+cascade = "1.0.1"
 
 [dev-dependencies]
 pretty_assertions = "1.3"
diff --git a/src/agent/onefuzz-task/src/tasks/fuzz/libfuzzer/generic.rs b/src/agent/onefuzz-task/src/tasks/fuzz/libfuzzer/generic.rs
index c7dbb0f494e..cf30e60ed1a 100644
--- a/src/agent/onefuzz-task/src/tasks/fuzz/libfuzzer/generic.rs
+++ b/src/agent/onefuzz-task/src/tasks/fuzz/libfuzzer/generic.rs
@@ -1,10 +1,9 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-use std::path::PathBuf;
-
 use anyhow::Result;
 use async_trait::async_trait;
+use cascade::cascade;
 use onefuzz::libfuzzer::LibFuzzer;
 
 use crate::tasks::fuzz::libfuzzer::common;
@@ -50,7 +49,8 @@ impl common::LibFuzzerType for GenericLibFuzzer {
         // The .local file is an empty file that tells DLL resolution to consider the same directory,
         // even for system (or KnownDLL) files.
         // See: https://learn.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-redirection#how-to-redirect-dlls-for-unpackaged-apps
-        let dotlocal_file = add_dotlocal_extension(target_exe);
+        let dotlocal_file = cascade! {target_exe; ..push(".local");};
+
         if let Err(e) = tokio::fs::write(dotlocal_file, &[]).await {
             // ignore already-exists error, report anything else
             if e.kind() != std::io::ErrorKind::AlreadyExists {
@@ -64,35 +64,5 @@ impl common::LibFuzzerType for GenericLibFuzzer {
     }
 }
 
-fn add_dotlocal_extension(mut path: PathBuf) -> PathBuf {
-    path.push(".local");
-    path
-}
-
 pub type Config = common::Config<GenericLibFuzzer>;
 pub type LibFuzzerFuzzTask = common::LibFuzzerFuzzTask<GenericLibFuzzer>;
-
-#[cfg(test)]
-mod test {
-    use std::path::PathBuf;
-
-    use super::add_dotlocal_extension;
-
-    #[test]
-    fn dotlocal_with_extension() {
-        let path = PathBuf::from("executable.exe");
-        assert_eq!(
-            PathBuf::from("executable.exe.local"),
-            add_dotlocal_extension(path)
-        );
-    }
-
-    #[test]
-    fn dotlocal_without_extension() {
-        let path = PathBuf::from("executable");
-        assert_eq!(
-            PathBuf::from("executable.local"),
-            add_dotlocal_extension(path)
-        );
-    }
-}