Resolve circular deps in testing

.gitignore

@@ -1,2 +1,3 @@
 **/target/*
 out.txt
+extensions/muxio-ext-test/tests/auto_tests.rs

Cargo.toml

@@ -19,6 +19,7 @@ publish.workspace = true # Inherit from workspace
 [workspace]
 members = [
     ".",
+    "extensions/muxio-ext-test",
     "extensions/muxio-rpc-service",
     "extensions/muxio-rpc-service-caller",
     "extensions/muxio-rpc-service-endpoint",
@@ -49,6 +50,7 @@ muxio-tokio-rpc-client = { path = "extensions/muxio-tokio-rpc-client", version =
 async-trait = "0.1.88"
 axum = { version = "0.8.4", features = ["ws"] }
 bitcode = "0.6.6"
+bytemuck = "1.23.1"
 criterion = { version = "0.6.0" }
 doc-comment = "0.3.3"
 bytes = "1.10.1"

extensions/muxio-ext-test/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "muxio-ext-test"
+authors.workspace = true
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+license.workspace = true
+publish = false
+
+[dev-dependencies]
+bytemuck.workspace = true
+tracing-subscriber = { workspace = true, features = ["fmt"] }
+muxio-tokio-rpc-client = { workspace = true }
+example-muxio-rpc-service-definition.workspace = true
+muxio-tokio-rpc-server = { workspace = true }
+muxio-rpc-service = { workspace = true }
+muxio-rpc-service-caller = { workspace = true }
+muxio-rpc-service-endpoint = { workspace = true, features = ["tokio_support"] }
+tracing = { workspace = true }
+tokio = { workspace = true, features = ["full"] }

extensions/muxio-ext-test/README.md

@@ -0,0 +1,13 @@
+# Muxio Ext Test
+
+This crate is intended for testing of crates that would otherwise have circular dependencies (and therefore not publishable).
+
+## Test discovery
+
+Any Rust files placed under the `tests/` directory (recursively) will be auto-included
+when running `cargo test`. A build script (`build.rs`) generates `tests/auto_tests.rs`
+which declares modules for each discovered `*.rs` file. Do not edit `tests/auto_tests.rs`
+manually; it is regenerated on test builds.
+
+If you need to add tests, create `.rs` files under `tests/` (for example `tests/foo/bar.rs`).
+The test runner will generate module names automatically.

extensions/muxio-ext-test/build.rs

@@ -0,0 +1,118 @@
+use std::collections::HashMap;
+use std::env;
+use std::fs::{self, File};
+use std::io::{self, Write};
+use std::path::{Path, PathBuf};
+
+fn main() {
+    let crate_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").expect("missing manifest dir"));
+    let tests_dir = crate_dir.join("tests");
+
+    if !tests_dir.is_dir() {
+        println!(
+            "cargo:rerun-if-changed={}",
+            crate_dir.join("tests").display()
+        );
+        return;
+    }
+
+    let mut discovered = Vec::new();
+    collect_test_files(&tests_dir, &tests_dir, &mut discovered)
+        .expect("failed to scan tests directory");
+    discovered.sort();
+
+    let out_path = tests_dir.join("auto_tests.rs");
+    let mut file = File::create(&out_path).expect("failed to create auto_tests.rs");
+
+    writeln!(file, "// @generated by build.rs. Do not edit.\n")
+        .expect("failed to write auto_tests header");
+
+    let mut suffix_counts: HashMap<String, usize> = HashMap::new();
+    for rel in &discovered {
+        if rel.file_name().and_then(|s| s.to_str()) == Some("auto_tests.rs") {
+            continue;
+        }
+        if rel.extension().and_then(|s| s.to_str()) != Some("rs") {
+            continue;
+        }
+
+        let rel_str = rel.to_string_lossy().replace('\\', "/");
+        let module_name = unique_ident(rel, &mut suffix_counts);
+
+        writeln!(file, "#[allow(non_snake_case)]").expect("failed to write attribute");
+        writeln!(file, "mod {} {{", module_name).expect("failed to start module");
+        writeln!(
+            file,
+            "    include!(concat!(env!(\"CARGO_MANIFEST_DIR\"), \"/tests/{}\"));",
+            rel_str
+        )
+        .expect("failed to write include");
+        writeln!(file, "}}\n").expect("failed to end module");
+    }
+
+    println!("cargo:rerun-if-changed={}", tests_dir.display());
+    for rel in &discovered {
+        println!("cargo:rerun-if-changed={}", tests_dir.join(rel).display());
+    }
+}
+
+fn collect_test_files(base: &Path, dir: &Path, acc: &mut Vec<PathBuf>) -> io::Result<()> {
+    for entry in fs::read_dir(dir)? {
+        let entry = entry?;
+        let path = entry.path();
+        if path
+            .file_name()
+            .and_then(|s| s.to_str())
+            .map(|s| s.starts_with('.'))
+            .unwrap_or(false)
+        {
+            continue;
+        }
+        if path.is_dir() {
+            collect_test_files(base, &path, acc)?;
+        } else if let Ok(rel) = path.strip_prefix(base) {
+            acc.push(rel.to_path_buf());
+        }
+    }
+    Ok(())
+}
+
+fn unique_ident(rel: &Path, suffix_counts: &mut HashMap<String, usize>) -> String {
+    let raw = rel.to_string_lossy();
+    let trimmed = raw.strip_suffix(".rs").unwrap_or(&raw);
+    let mut ident: String = trimmed
+        .chars()
+        .map(|c| match c {
+            'a'..='z' | 'A'..='Z' | '0'..='9' => c,
+            _ => '_',
+        })
+        .collect();
+
+    while ident.contains("__") {
+        ident = ident.replace("__", "_");
+    }
+    if ident.ends_with('_') {
+        ident.pop();
+    }
+    if ident.is_empty() {
+        ident.push_str("test");
+    }
+    if ident
+        .chars()
+        .next()
+        .map(|c| c.is_ascii_digit())
+        .unwrap_or(true)
+    {
+        ident.insert(0, '_');
+    }
+
+    let counter = suffix_counts.entry(ident.clone()).or_insert(0);
+    if *counter == 0 {
+        *counter = 1;
+        ident
+    } else {
+        let new_ident = format!("{}_{counter}", ident);
+        *counter += 1;
+        new_ident
+    }
+}

extensions/muxio-ext-test/src/lib.rs

@@ -0,0 +1 @@
+// no-op library crate used for housing integration tests.

extensions/muxio-tokio-rpc-server/tests/proxy_error_propagation_tests.rs → extensions/muxio-ext-test/tests/muxio-tokio-rpc-server/proxy_error_propagation_tests.rs

@@ -1,8 +1,8 @@
-//! This integration test verifies error propagation through a proxy server.
-//!
-//! Scenario: Client A -> Server (Proxy) -> Client B (Provider).
-//! When Client B disconnects (crashes) while a call from Client A is pending,
-//! the error must propagate back through Server to Client A.
+// This integration test verifies error propagation through a proxy server.
+//
+// Scenario: Client A -> Server (Proxy) -> Client B (Provider).
+// When Client B disconnects (crashes) while a call from Client A is pending,
+// the error must propagate back through Server to Client A.
 
 use example_muxio_rpc_service_definition::prebuffered::Echo;
 use muxio_rpc_service::{

extensions/muxio-tokio-rpc-client/Cargo.toml

@@ -22,6 +22,9 @@ futures = { workspace = true }
 tracing = { workspace = true }
 
 [dev-dependencies]
-muxio-tokio-rpc-server = { workspace = true }
+tokio = { workspace = true, features = ["full"] }
+tokio-tungstenite = { workspace = true }
 example-muxio-rpc-service-definition = { workspace = true }
+futures-util = { workspace = true }
 axum = { workspace = true }
+muxio-tokio-rpc-server = { workspace = true }

extensions/muxio-tokio-rpc-server/Cargo.toml

@@ -20,11 +20,3 @@ muxio-rpc-service = { workspace = true }
 muxio-rpc-service-endpoint = { workspace = true, features=["tokio_support"] }
 async-trait = { workspace = true }
 tracing = { workspace = true }
-
-[dev-dependencies]
-bitcode.workspace = true
-bytemuck = "1.23.1"
-example-muxio-rpc-service-definition.workspace = true
-muxio-tokio-rpc-client.workspace = true
-muxio-tokio-rpc-server.workspace = true
-tracing-subscriber = { workspace = true, features = ["fmt"] }

extensions/muxio-tokio-rpc-server/tests/README.md

@@ -0,0 +1 @@
+Note: `muxio-tokio-rpc-server` tests currently reside in [muxio-ext-test](../../muxio-ext-test/) in order to resolve issues with circular dependencies for publishing.