Add tests for cargo project with a dependency.

PiperOrigin-RevId: 895398959

Author: thunderseethe

cargo/cc_bindings_from_rs/cargo-cpp_api_from_rust/tests/test.rs

@@ -180,3 +180,35 @@ fn test_subcommand_caching() -> Result<(), Box<dyn std::error::Error>> {
 
     Ok(())
 }
+
+#[test] // allow_core_test
+fn test_subcommand_with_dependency() -> Result<(), Box<dyn std::error::Error>> {
+    let tmp_dir = tempfile::tempdir()?;
+    let cwd = std::env::current_dir()?;
+    let project_dir = cwd.join("tests/test_with_dependency");
+
+    let mut cmd = setup_command(&tmp_dir, &project_dir);
+    cmd.arg("cpp_api_from_rust");
+
+    let output = cmd.output().expect("Failed to execute");
+
+    if !output.status.success() {
+        println!("{}", String::from_utf8_lossy(&output.stdout));
+        eprintln!("{}", String::from_utf8_lossy(&output.stderr));
+        panic!("cargo-cpp_api_from_rust failed");
+    }
+
+    // Verify output files
+    let target_dir = tmp_dir.path();
+    let debug_dir = target_dir.join("debug");
+    let headers_dir = debug_dir.join("headers");
+
+    // We expect to find headers for both the root crate and its dependency.
+    assert!(headers_dir.join("test_with_dependency.h").exists());
+    assert!(headers_dir.join("test_dependency.h").exists());
+
+    // We expect the final staticlib for the root crate.
+    assert!(debug_dir.join("libtest_with_dependency.a").exists());
+
+    Ok(())
+}

cargo/cc_bindings_from_rs/cargo-cpp_api_from_rust/tests/test_with_dependency/Cargo.toml

@@ -0,0 +1,13 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+[package]
+name = "test_with_dependency"
+version = "0.1.0"
+edition = "2024"
+
+# This is needed to prevent this project from being part of the `crubit/` workspace.
+[workspace]
+
+[dependencies]
+test_dependency = { path = "test_dependency" }

cargo/cc_bindings_from_rs/cargo-cpp_api_from_rust/tests/test_with_dependency/src/lib.rs

@@ -0,0 +1,7 @@
+// Part of the Crubit project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+pub fn add_with_dep(left: u64, right: u64) -> u64 {
+    test_dependency::dependency_add(left, right)
+}

cargo/cc_bindings_from_rs/cargo-cpp_api_from_rust/tests/test_with_dependency/test_dependency/Cargo.toml

@@ -0,0 +1,9 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+[package]
+name = "test_dependency"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

cargo/cc_bindings_from_rs/cargo-cpp_api_from_rust/tests/test_with_dependency/test_dependency/src/lib.rs

@@ -0,0 +1,7 @@
+// Part of the Crubit project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+pub fn dependency_add(left: u64, right: u64) -> u64 {
+    left + right
+}

cc_bindings_from_rs/cargo-cpp_api_from_rust.rs

@@ -192,6 +192,7 @@ fn main() -> Result<()> {
         let rs_crate_name = crate_name.replace('-', "_");
         let hash = &artifact_info.hash;
         let intermediate_h = deps_dir.join(format!("{}-{}.h", crate_name, hash));
+        let final_h = headers_dir.join(format!("{}.h", crate_name));
         let intermediate_rs = deps_dir.join(format!("lib{}-{}.rs", crate_name, hash));
 
         if artifact_info.fresh && intermediate_h.exists() && intermediate_rs.exists() {
@@ -200,6 +201,10 @@ fn main() -> Result<()> {
                 "#[path = {:?}]pub mod r#{};\n",
                 intermediate_rs, rs_crate_name
             ));
+            // Final outputs: copy/rename from deps/ to their final locations.
+            if !final_h.exists() {
+                fs::copy(&intermediate_h, &final_h)?;
+            }
             continue;
         }
 
@@ -246,7 +251,7 @@ fn main() -> Result<()> {
         pkg_to_header.insert(pkg_id.repr, intermediate_h.to_string());
 
         // Final outputs: copy/rename from deps/ to their final locations.
-        fs::copy(&intermediate_h, headers_dir.join(format!("{}.h", crate_name)))?;
+        fs::copy(&intermediate_h, &final_h)?;
     }
 
     let root_name = &root.name;