Fix rust-lang#686: send showMessage when missing root Cargo.toml

Author: alexheretic

src/actions/mod.rs

@@ -83,6 +83,15 @@ impl ActionContext {
         client_capabilities: lsp_data::ClientCapabilities,
         out: O,
     ) {
+        let cargo_toml = current_project.join("Cargo.toml");
+        if !cargo_toml.is_file() {
+            let warning: Notification<ShowMessage> = Notification::new(ShowMessageParams {
+                typ: MessageType::Warning,
+                message: format!("A {:?} file is required to support all RLS features", cargo_toml)
+            });
+            out.notify(warning);
+        }
+
         let ctx = match *self {
             ActionContext::Uninit(ref uninit) => {
                 let ctx = InitActionContext::new(

src/test/mod.rs

@@ -15,6 +15,7 @@ extern crate json;
 
 #[macro_use]
 mod harness;
+mod warnings;
 
 use analysis;
 use actions::{requests, notifications};

src/test/warnings.rs

@@ -0,0 +1,34 @@
+use super::*;
+
+#[test]
+fn warn_missing_root_cargo_toml() {
+    let mut env = Environment::new("no_cargo_toml");
+
+    let root_path = env.cache.abs_path(Path::new("."));
+    let messages = vec![
+        initialize(0, root_path.as_os_str().to_str().map(|x| x.to_owned())).to_string(),
+    ];
+
+    let (mut server, results) = env.mock_server(messages);
+    // Initialize and build.
+    assert_eq!(
+        ls_server::LsService::handle_message(&mut server),
+        ls_server::ServerStateChange::Continue
+    );
+    {
+        wait_for_n_results!(1, results);
+        let response = json::parse(&results.lock().unwrap().remove(0)).unwrap();
+        println!("{}", response.pretty(2));
+        assert!(response["result"]["capabilities"].is_object());
+    }
+    {
+        // showMessage warning
+        wait_for_n_results!(1, results);
+        let response = json::parse(&results.lock().unwrap().remove(0)).unwrap();
+        println!("{}", response.pretty(2));
+        assert_eq!(response["method"], "window/showMessage");
+        assert_eq!(response["params"]["type"], 2, "Expected 'warning' message type");
+        let message = response["params"]["message"].as_str().unwrap();
+        assert!(message.contains("Cargo.toml"));
+    }
+}

test_data/no_cargo_toml/src/main.rs

@@ -0,0 +1,26 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+struct Bar {
+    x: u64,
+}
+
+#[test]
+pub fn test_fn() {
+    let bar = Bar { x: 4 };
+    println!("bar: {}", bar.x);
+}
+
+pub fn main() {
+    let world = "world";
+    println!("Hello, {}!", world);
+
+    let bar2 = Bar { x: 5 };
+    println!("bar2: {}", bar2.x);
+}