7 files changed, 57 insertions, 28 deletions

diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 04f7eb741..6d1154056 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -24,7 +24,7 @@ use rustc_hash::FxHashMap;
 ///
 /// We use absolute paths here, `cargo metadata` guarantees to always produce
 /// abs paths.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct CargoWorkspace {
     packages: Arena<PackageData>,
     targets: Arena<TargetData>,
@@ -68,7 +68,7 @@ pub type Package = Idx<PackageData>;
 
 pub type Target = Idx<TargetData>;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct PackageData {
     pub version: String,
     pub name: String,
@@ -83,13 +83,13 @@ pub struct PackageData {
     pub proc_macro_dylib_path: Option<AbsPathBuf>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct PackageDependency {
     pub pkg: Package,
     pub name: String,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct TargetData {
     pub package: Package,
     pub name: String,
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 5d1f871c4..b9c5424bf 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -24,7 +24,7 @@ pub use crate::{
 };
 pub use ra_proc_macro::ProcMacroClient;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub enum ProjectWorkspace {
     /// Project workspace was discovered by running `cargo metadata` and `rustc --print sysroot`.
     Cargo { cargo: CargoWorkspace, sysroot: Sysroot },
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index fc1673ede..68d134da4 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -3,19 +3,19 @@
 use std::{convert::TryFrom, env, ops, path::Path, process::Command};
 
 use anyhow::{bail, format_err, Result};
+use paths::{AbsPath, AbsPathBuf};
 use ra_arena::{Arena, Idx};
 
 use crate::output;
-use paths::{AbsPath, AbsPathBuf};
 
-#[derive(Default, Debug, Clone)]
+#[derive(Default, Debug, Clone, Eq, PartialEq)]
 pub struct Sysroot {
     crates: Arena<SysrootCrateData>,
 }
 
 pub type SysrootCrate = Idx<SysrootCrateData>;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct SysrootCrateData {
     pub name: String,
     pub root: AbsPathBuf,
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 9dd81b4fc..ed5e52871 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -29,6 +29,7 @@ pub struct Config {
     pub files: FilesConfig,
     pub notifications: NotificationsConfig,
 
+    pub cargo_autoreload: bool,
     pub cargo: CargoConfig,
     pub rustfmt: RustfmtConfig,
     pub flycheck: Option<FlycheckConfig>,
@@ -141,6 +142,7 @@ impl Config {
             files: FilesConfig { watcher: FilesWatcher::Notify, exclude: Vec::new() },
             notifications: NotificationsConfig { cargo_toml_not_found: true },
 
+            cargo_autoreload: true,
             cargo: CargoConfig::default(),
             rustfmt: RustfmtConfig::Rustfmt { extra_args: Vec::new() },
             flycheck: Some(FlycheckConfig::CargoCommand {
@@ -189,6 +191,7 @@ impl Config {
         };
         self.notifications =
             NotificationsConfig { cargo_toml_not_found: data.notifications_cargoTomlNotFound };
+        self.cargo_autoreload = data.cargo_autoreload;
         self.cargo = CargoConfig {
             no_default_features: data.cargo_noDefaultFeatures,
             all_features: data.cargo_allFeatures,
@@ -364,6 +367,7 @@ config_data! {
     struct ConfigData {
         callInfo_full: bool = true,
 
+        cargo_autoreload: bool           = true,
         cargo_allFeatures: bool          = false,
         cargo_features: Vec<String>      = Vec::new(),
         cargo_loadOutDirsFromCheck: bool = false,
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index b48239058..96e2399ce 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -314,19 +314,6 @@ impl GlobalState {
         Ok(())
     }
 
-    fn transition(&mut self, new_status: Status) {
-        self.status = Status::Ready;
-        if self.config.client_caps.status_notification {
-            let lsp_status = match new_status {
-                Status::Loading => lsp_ext::Status::Loading,
-                Status::Ready => lsp_ext::Status::Ready,
-                Status::Invalid => lsp_ext::Status::Invalid,
-                Status::NeedsReload => lsp_ext::Status::NeedsReload,
-            };
-            self.send_notification::<lsp_ext::StatusNotification>(lsp_status);
-        }
-    }
-
     fn on_request(&mut self, request_received: Instant, req: Request) -> Result<()> {
         self.register_request(&req, request_received);
 
@@ -441,12 +428,7 @@ impl GlobalState {
                 if let Some(flycheck) = &this.flycheck {
                     flycheck.handle.update();
                 }
-                let uri = params.text_document.uri.as_str();
-                if uri.ends_with("Cargo.toml") || uri.ends_with("Cargo.lock") {
-                    if matches!(this.status, Status::Ready | Status::Invalid) {
-                        this.transition(Status::NeedsReload);
-                    }
-                }
+                this.maybe_refresh(params.text_document.uri.as_str());
                 Ok(())
             })?
             .on::<lsp_types::notification::DidChangeConfiguration>(|this, _params| {
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
index 74c3344df..0a201fceb 100644
--- a/crates/rust-analyzer/src/reload.rs
+++ b/crates/rust-analyzer/src/reload.rs
@@ -10,7 +10,8 @@ use vfs::{file_set::FileSetConfig, AbsPath};
 
 use crate::{
     config::{Config, FilesWatcher, LinkedProject},
-    global_state::{GlobalState, Handle},
+    global_state::{GlobalState, Handle, Status},
+    lsp_ext,
     main_loop::Task,
 };
 
@@ -26,6 +27,32 @@ impl GlobalState {
             self.reload_flycheck();
         }
     }
+    pub(crate) fn maybe_refresh(&mut self, saved_doc_url: &str) {
+        if !(saved_doc_url.ends_with("Cargo.toml") || saved_doc_url.ends_with("Cargo.lock")) {
+            return;
+        }
+        match self.status {
+            Status::Loading | Status::NeedsReload => return,
+            Status::Ready | Status::Invalid => (),
+        }
+        if self.config.cargo_autoreload {
+            self.fetch_workspaces();
+        } else {
+            self.transition(Status::NeedsReload);
+        }
+    }
+    pub(crate) fn transition(&mut self, new_status: Status) {
+        self.status = new_status;
+        if self.config.client_caps.status_notification {
+            let lsp_status = match new_status {
+                Status::Loading => lsp_ext::Status::Loading,
+                Status::Ready => lsp_ext::Status::Ready,
+                Status::Invalid => lsp_ext::Status::Invalid,
+                Status::NeedsReload => lsp_ext::Status::NeedsReload,
+            };
+            self.send_notification::<lsp_ext::StatusNotification>(lsp_status);
+        }
+    }
     pub(crate) fn fetch_workspaces(&mut self) {
         self.task_pool.handle.spawn({
             let linked_projects = self.config.linked_projects.clone();
@@ -53,10 +80,13 @@ impl GlobalState {
     }
     pub(crate) fn switch_workspaces(&mut self, workspaces: Vec<anyhow::Result<ProjectWorkspace>>) {
         log::info!("reloading projects: {:?}", self.config.linked_projects);
+
+        let mut has_errors = false;
         let workspaces = workspaces
             .into_iter()
             .filter_map(|res| {
                 res.map_err(|err| {
+                    has_errors = true;
                     log::error!("failed to load workspace: {:#}", err);
                     self.show_message(
                         lsp_types::MessageType::Error,
@@ -67,6 +97,14 @@ impl GlobalState {
             })
             .collect::<Vec<_>>();
 
+        if &*self.workspaces == &workspaces {
+            return;
+        }
+
+        if !self.workspaces.is_empty() && has_errors {
+            return;
+        }
+
         if let FilesWatcher::Client = self.config.files.watcher {
             let registration_options = lsp_types::DidChangeWatchedFilesRegistrationOptions {
                 watchers: workspaces
diff --git a/editors/code/package.json b/editors/code/package.json
index 743a2290c..aac4ba94f 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -237,6 +237,11 @@
                     "default": true,
                     "markdownDescription": "Whether to show `can't find Cargo.toml` error message"
                 },
+                "rust-analyzer.cargo.autoreload": {
+                    "type": "boolean",
+                    "default": true,
+                    "markdownDescription": "Automatically refresh project info via `cargo metadata` on Cargo.toml changes"
+                },
                 "rust-analyzer.cargo.noDefaultFeatures": {
                     "type": "boolean",
                     "default": false,