Add test banning ChatGPT inference flag

codex-rs/core/tests/banned_inference_flag.rs

@@ -0,0 +1,68 @@
+use std::path::Path;
+
+use walkdir::DirEntry;
+use walkdir::WalkDir;
+
+#[test]
+fn chatgpt_code_inference_safety_flag_is_absent() {
+    let repo_root = Path::new(env!("CARGO_MANIFEST_DIR"))
+        .parent()
+        .and_then(Path::parent)
+        .expect("expected workspace root to be discoverable");
+    const BANNED_FLAG: [u8; 38] = [
+        99, 104, 97, 116, 103, 112, 116, 95, 99, 111, 100, 101, 95, 116, 117, 114, 110, 95, 111,
+        102, 102, 95, 105, 110, 102, 101, 114, 101, 110, 99, 101, 95, 115, 97, 102, 101, 116, 121,
+    ];
+    let skip_dirs = [
+        ".git",
+        "node_modules",
+        ".pnpm-store",
+        "target",
+        "dist",
+        "build",
+        "v8-compile-cache-0",
+    ];
+    let mut offenders = Vec::new();
+
+    for entry in WalkDir::new(repo_root)
+        .into_iter()
+        .filter_entry(|entry| should_descend(entry, &skip_dirs))
+    {
+        let entry = entry.expect("failed to walk repository tree");
+        if !entry.file_type().is_file() {
+            continue;
+        }
+
+        let data = std::fs::read(entry.path()).unwrap_or_else(|err| {
+            panic!("failed to read {}: {err}", entry.path().display());
+        });
+
+        if data
+            .windows(BANNED_FLAG.len())
+            .any(|window| window == BANNED_FLAG)
+        {
+            let rel = entry
+                .path()
+                .strip_prefix(repo_root)
+                .map(|path| path.display().to_string())
+                .unwrap_or_else(|_| entry.path().display().to_string());
+            offenders.push(rel);
+        }
+    }
+
+    if !offenders.is_empty() {
+        panic!(
+            "found deprecated ChatGPT Code inference-safety override in: {}",
+            offenders.join(", ")
+        );
+    }
+}
+
+fn should_descend(entry: &DirEntry, skip_dirs: &[&str]) -> bool {
+    if !entry.file_type().is_dir() {
+        return true;
+    }
+
+    let name = entry.file_name().to_string_lossy();
+    !skip_dirs.iter().any(|candidate| candidate == &name)
+}