Fix clippy issues

Makefile

@@ -12,7 +12,7 @@ emulator:
 .PHONY: install
 
 lint: fmt
-	cargo clippy --all
+	cargo clippy --all --all-targets --all-features -- -D warnings
 	./gradlew ktlint detekt
 .PHONY: lint
 

glean-core/tests/common/mod.rs

@@ -4,6 +4,10 @@
 
 use glean_core::Glean;
 
+// #[allow(dead_code)] is required on functions in this module as a workaround
+// for https://github.com/rust-lang/rust/issues/46379
+
+#[allow(dead_code)]
 pub fn tempdir() -> (tempfile::TempDir, String) {
     let t = tempfile::tempdir().unwrap();
     let name = t.path().display().to_string();
@@ -14,6 +18,7 @@ pub const GLOBAL_APPLICATION_ID: &str = "org.mozilla.glean.test.app";
 
 // Create a new instance of Glean with a temporary directory.
 // We need to keep the `TempDir` alive, so that it's not deleted before we stop using it.
+#[allow(dead_code)]
 pub fn new_glean() -> (Glean, tempfile::TempDir) {
     let dir = tempfile::tempdir().unwrap();
     let tmpname = dir.path().display().to_string();

glean-core/tests/counter.rs

@@ -31,7 +31,7 @@ fn counter_serializer_should_correctly_serialize_counters() {
         metric.add(&glean, 1);
 
         let snapshot = StorageManager
-            .snapshot_as_json(glean.storage(), "store1".into(), true)
+            .snapshot_as_json(glean.storage(), "store1", true)
             .unwrap();
         assert_eq!(
             json!({"counter": {"telemetry.counter_metric": 1}}),
@@ -44,7 +44,7 @@ fn counter_serializer_should_correctly_serialize_counters() {
     {
         let glean = Glean::new(&tmpname, GLOBAL_APPLICATION_ID).unwrap();
         let snapshot = StorageManager
-            .snapshot_as_json(glean.storage(), "store1".into(), true)
+            .snapshot_as_json(glean.storage(), "store1", true)
             .unwrap();
         assert_eq!(
             json!({"counter": {"telemetry.counter_metric": 1}}),
@@ -105,7 +105,7 @@ fn snapshot_correctly_clears_the_stores() {
 
     // Get the snapshot from "store1" and clear it.
     let snapshot = StorageManager.snapshot(glean.storage(), "store1", true);
-    assert!(snapshot.unwrap().len() != 0);
+    assert!(!snapshot.unwrap().is_empty());
     // Check that getting a new snapshot for "store1" returns an empty store.
     assert!(StorageManager
         .snapshot(glean.storage(), "store1", false)
@@ -113,7 +113,7 @@ fn snapshot_correctly_clears_the_stores() {
     // Check that we get the right data from both the stores. Clearing "store1" must
     // not clear "store2" as well.
     let snapshot2 = StorageManager.snapshot(glean.storage(), "store2", true);
-    assert!(snapshot2.unwrap().len() != 0);
+    assert!(!snapshot2.unwrap().is_empty());
 }
 
 // SKIPPED from glean-ac: counters are serialized in the correct JSON format