Fix clippy warnings for //tools/rust_analyzer:gen_rust_project (#746)

* Fix clippy warnings for //tools/rust_analyzer:gen_rust_project

* buildifier tools/rustfmt/BUILD.bazel

tools/rust_analyzer/BUILD.bazel

@@ -1,4 +1,4 @@
-load("//rust:defs.bzl", "rust_binary")
+load("//rust:defs.bzl", "rust_binary", "rust_clippy")
 
 rust_binary(
     name = "gen_rust_project",
@@ -11,3 +11,12 @@ rust_binary(
         "//util/label",
     ],
 )
+
+rust_clippy(
+    name = "gen_rust_project_clippy",
+    testonly = True,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":gen_rust_project",
+    ],
+)

tools/rust_analyzer/main.rs

@@ -108,8 +108,8 @@ fn parse_config() -> anyhow::Result<Config> {
     let output = String::from_utf8_lossy(&output.stdout.as_slice());
     let bazel_info = output
         .trim()
-        .split("\n")
-        .map(|line| line.split_at(line.find(":").expect("missing `:` in bazel info output")))
+        .split('\n')
+        .map(|line| line.split_at(line.find(':').expect("missing `:` in bazel info output")))
         .map(|(k, v)| (k, (&v[1..]).trim()))
         .collect::<HashMap<_, _>>();
 

tools/rustfmt/BUILD.bazel

@@ -1,4 +1,4 @@
-load("//rust:defs.bzl", "rust_binary", "rust_library")
+load("//rust:defs.bzl", "rust_binary", "rust_clippy", "rust_library")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -58,3 +58,12 @@ rust_binary(
         "//tools/runfiles",
     ],
 )
+
+rust_clippy(
+    name = "rustfmt_clippy",
+    testonly = True,
+    visibility = ["//visibility:private"],
+    deps = [
+        ":rustfmt",
+    ],
+)