Test against clippy warnings in stubs (#1830)

.gitignore

@@ -5,6 +5,6 @@
 tmp
 /bin/configlet
 exercises/*/*/Cargo.lock
-exercises/*/*/clippy.log
+clippy.log
 .vscode
 .prob-spec

exercises/concept/csv-builder/Cargo.toml

@@ -2,3 +2,6 @@
 name = "csv_builder"
 version = "0.1.0"
 edition = "2021"
+
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/bowling/Cargo.toml

@@ -2,3 +2,6 @@
 edition = "2021"
 name = "bowling"
 version = "1.2.0"
+
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/fizzy/Cargo.toml

@@ -3,4 +3,5 @@ name = "fizzy"
 version = "0.0.0"
 edition = "2021"
 
-[dependencies]
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/forth/Cargo.toml

@@ -2,3 +2,6 @@
 edition = "2021"
 name = "forth"
 version = "1.7.0"
+
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/grade-school/Cargo.toml

@@ -2,3 +2,6 @@
 edition = "2021"
 name = "grade-school"
 version = "0.0.0"
+
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/react/Cargo.toml

@@ -2,3 +2,6 @@
 edition = "2021"
 name = "react"
 version = "2.0.0"
+
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/robot-name/Cargo.toml

@@ -3,4 +3,5 @@ edition = "2021"
 name = "robot-name"
 version = "0.0.0"
 
-[dependencies]
+[lints.clippy]
+new_without_default = "allow"

exercises/practice/simple-linked-list/Cargo.toml

@@ -3,4 +3,5 @@ edition = "2021"
 name = "simple_linked_list"
 version = "0.1.0"
 
-[dependencies]
+[lints.clippy]
+new_without_default = "allow"

rust-tooling/ci-tests/Cargo.toml

@@ -14,4 +14,5 @@ glob = "0.3.1"
 ignore = "0.4.20"
 models = { version = "0.1.0", path = "../models" }
 serde_json = "1.0.108"
+tempdir = "0.3.7"
 utils = { version = "0.1.0", path = "../utils" }

rust-tooling/ci-tests/tests/stubs_are_warning_free.rs

@@ -0,0 +1,83 @@
+use std::process::{Command, Stdio};
+
+use glob::glob;
+
+#[test]
+fn stubs_are_warning_free() {
+    utils::fs::cd_into_repo_root();
+
+    let temp_dir = tempdir::TempDir::new("exercism-rust").unwrap();
+
+    let mut handles = vec![];
+
+    for manifest in glob("exercises/*/*/Cargo.toml")
+        .unwrap()
+        .map(Result::unwrap)
+    {
+        if std::fs::read_to_string(&manifest.parent().unwrap().join(".meta").join("config.json"))
+            .unwrap()
+            .contains("allowed-to-not-compile")
+        {
+            continue;
+        }
+        let slug = manifest
+            .parent()
+            .unwrap()
+            .file_name()
+            .unwrap()
+            .to_str()
+            .unwrap();
+        let handle = Command::new("cargo")
+            .args([
+                "clippy",
+                "--quiet",
+                "--manifest-path",
+                &manifest.display().to_string(),
+                "--target-dir",
+                &temp_dir.path().join(slug).display().to_string(),
+                "--",
+                // necessary for clippy to return a non-zero exit code
+                // if it finds warnings
+                "--deny",
+                "warnings",
+            ])
+            .stderr(Stdio::piped())
+            .spawn()
+            .unwrap();
+
+        handles.push((slug.to_string(), handle));
+    }
+
+    let mut log = String::new();
+
+    for (slug, handle) in handles {
+        let output = handle.wait_with_output().unwrap();
+
+        if output.status.success() {
+            continue;
+        }
+        let stderr = String::from_utf8(output.stderr).unwrap();
+        log.push_str(&format!(
+            "\
+################################################################
+################
+################    {slug}
+
+{stderr}
+
+"
+        ));
+    }
+
+    if !log.is_empty() {
+        std::fs::write("clippy.log", &log).expect("should write clippy.log");
+    }
+    assert!(
+        log.is_empty(),
+        "
+    ╔═════════════════════════════════════════╗
+    ║ clippy found warnings, check clippy.log ║
+    ╚═════════════════════════════════════════╝
+    "
+    );
+}