tests(cargo-codspeed): create a testcase for handling rustflags from the cargo config

Author: art049

crates/cargo-codspeed/tests/.gitignore

@@ -1,2 +1,2 @@
+*/target
 */Cargo.lock
-*/target/

crates/cargo-codspeed/tests/cargo_config.in/.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+rustflags = ["--cfg", "custom_feature_flag"]

crates/cargo-codspeed/tests/cargo_config.in/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "cargo_config_test"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+codspeed-criterion-compat = { path = "../../../criterion_compat" }
+
+[workspace]
+
+[[bench]]
+name = "cargo_config_bench"
+harness = false

crates/cargo-codspeed/tests/cargo_config.in/benches/cargo_config_bench.rs

@@ -0,0 +1,17 @@
+use codspeed_criterion_compat::{criterion_group, criterion_main, Criterion};
+
+fn bench_failing_without_custom_flag(c: &mut Criterion) {
+    c.bench_function("custom_flag_disabled", |b| {
+        b.iter(|| {
+            // This will cause a compilation error if custom_feature_flag is not set
+            #[cfg(not(custom_feature_flag))]
+            compile_error!(
+                "custom_feature_flag is not enabled - .cargo/config.toml rustflags not applied"
+            );
+        })
+    });
+}
+
+criterion_group!(benches, bench_failing_without_custom_flag);
+
+criterion_main!(benches);

crates/cargo-codspeed/tests/cargo_config.in/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo::rustc-check-cfg=cfg(custom_feature_flag)");
+}

crates/cargo-codspeed/tests/cargo_config.rs

@@ -0,0 +1,35 @@
+use std::process::Command;
+
+mod helpers;
+use helpers::*;
+
+#[test]
+fn test_cargo_config_rustflags() {
+    let tmp_dir = setup("tests/cargo_config.in", Project::Simple);
+
+    // Test that cargo bench works with the custom flag
+    let output = Command::new("cargo")
+        .arg("bench")
+        .arg("--no-run")
+        .current_dir(&tmp_dir)
+        .output()
+        .expect("Failed to execute cargo bench");
+
+    assert!(
+        output.status.success(),
+        "cargo codspeed bench should succeed with .cargo/config.toml rustflags",
+    );
+
+    // Test that cargo codspeed build also works with the custom flag
+    let output = cargo_codspeed(&tmp_dir)
+        .arg("build")
+        .output()
+        .expect("Failed to execute cargo codspeed build");
+
+    assert!(
+        output.status.success(),
+        "cargo codspeed build should succeed with .cargo/config.toml rustflags",
+    );
+
+    teardown(tmp_dir);
+}