Rust implementation of integration test

Cargo.toml

@@ -38,6 +38,8 @@ clippy_lints = { version = "0.0.212", path = "clippy_lints" }
 regex = "1"
 semver = "0.9"
 rustc_tools_util = { version = "0.2.0", path = "rustc_tools_util"}
+git2 = { version = "0.10", optional = true }
+tempfile = { version = "3.1.0", optional = true }
 
 [dev-dependencies]
 cargo_metadata = "0.9.0"
@@ -58,3 +60,4 @@ rustc_tools_util = { version = "0.2.0", path = "rustc_tools_util"}
 
 [features]
 deny-warnings = []
+integration = ["git2", "tempfile"]

tests/integration.rs

@@ -0,0 +1,75 @@
+#![cfg(feature = "integration")]
+
+use git2::Repository;
+use tempfile;
+
+use std::env;
+use std::process::Command;
+
+#[cfg_attr(feature = "integration", test)]
+fn integration_test() {
+    let repo_name = env::var("INTEGRATION").expect("`INTEGRATION` var not set");
+    let repo_url = format!("https://github.com/{}", repo_name);
+    let crate_name = repo_name
+        .split('/')
+        .nth(1)
+        .expect("repo name should have format `<org>/<name>`");
+
+    let repo_dir = tempfile::tempdir()
+        .expect("couldn't create temp dir")
+        .path()
+        .join(crate_name);
+
+    Repository::clone(&repo_url, &repo_dir).expect("clone of repo failed");
+
+    let root_dir = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let target_dir = std::path::Path::new(&root_dir).join("target");
+    let clippy_binary = target_dir.join(env!("PROFILE")).join("cargo-clippy");
+
+    let output = Command::new(clippy_binary)
+        .current_dir(repo_dir)
+        .env("RUST_BACKTRACE", "full")
+        .env("CARGO_TARGET_DIR", target_dir)
+        .args(&[
+            "clippy",
+            "--all-targets",
+            "--all-features",
+            "--",
+            "--cap-lints",
+            "warn",
+            "-Wclippy::pedantic",
+            "-Wclippy::nursery",
+        ])
+        .output()
+        .expect("unable to run clippy");
+
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    if stderr.contains("internal compiler error") {
+        let backtrace_start = stderr
+            .find("thread 'rustc' panicked at")
+            .expect("start of backtrace not found");
+        let backtrace_end = stderr
+            .rfind("error: internal compiler error")
+            .expect("end of backtrace not found");
+
+        panic!(
+            "internal compiler error\nBacktrace:\n\n{}",
+            &stderr[backtrace_start..backtrace_end]
+        );
+    } else if stderr.contains("query stack during panic") {
+        panic!("query stack during panic in the output");
+    } else if stderr.contains("E0463") {
+        panic!("error: E0463");
+    }
+
+    match output.status.code() {
+        Some(code) => {
+            if code == 0 {
+                eprintln!("Compilation successful");
+            } else {
+                eprintln!("Compilation failed. Exit code: {}", code);
+            }
+        },
+        None => panic!("Process terminated by signal"),
+    }
+}