9 files changed, 33 insertions, 52 deletions

diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index e0bb75666..eeca67ee1 100644
--- a/crates/ra_lsp_server/src/caps.rs
+++ b/crates/ra_lsp_server/src/caps.rs
@@ -1,11 +1,12 @@
-//! FIXME: write short doc here
+//! Advertizes the capabilities of the LSP Server.
 
 use lsp_types::{
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions,
-    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability, GenericCapability,
-    ImplementationProviderCapability, RenameOptions, RenameProviderCapability, ServerCapabilities,
-    SignatureHelpOptions, TextDocumentSyncCapability, TextDocumentSyncKind,
-    TextDocumentSyncOptions, TypeDefinitionProviderCapability, WorkDoneProgressOptions,
+    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability,
+    ImplementationProviderCapability, RenameOptions, RenameProviderCapability,
+    SelectionRangeProviderCapability, ServerCapabilities, SignatureHelpOptions,
+    TextDocumentSyncCapability, TextDocumentSyncKind, TextDocumentSyncOptions,
+    TypeDefinitionProviderCapability, WorkDoneProgressOptions,
 };
 
 pub fn server_capabilities() -> ServerCapabilities {
@@ -44,7 +45,7 @@ pub fn server_capabilities() -> ServerCapabilities {
             first_trigger_character: "=".to_string(),
             more_trigger_character: Some(vec![".".to_string(), ">".to_string()]),
         }),
-        selection_range_provider: Some(GenericCapability::default()),
+        selection_range_provider: Some(SelectionRangeProviderCapability::Simple(true)),
         folding_range_provider: Some(FoldingRangeProviderCapability::Simple(true)),
         rename_provider: Some(RenameProviderCapability::Options(RenameOptions {
             prepare_provider: Some(true),
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index 5561f6270..e93d4ea33 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Convenience module responsible for translating between rust-analyzer's types and LSP types.
 
 use lsp_types::{
     self, CreateFile, DiagnosticSeverity, DocumentChangeOperation, DocumentChanges, Documentation,
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 965e7c53c..81fd08c91 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -1,4 +1,5 @@
-//! FIXME: write short doc here
+//! The main loop of `ra_lsp_server` responsible for dispatching LSP requests/replies and
+//! notifications back to the client.
 
 mod handlers;
 mod subscriptions;
@@ -131,7 +132,7 @@ pub fn main_loop(
         let feature_flags = {
             let mut ff = FeatureFlags::default();
             for (flag, value) in config.feature_flags {
-                if let Err(_) = ff.set(flag.as_str(), value) {
+                if ff.set(flag.as_str(), value).is_err() {
                     log::error!("unknown feature flag: {:?}", flag);
                     show_message(
                         req::MessageType::Error,
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 5b64b27cd..39eb3df3e 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -1,4 +1,5 @@
-//! FIXME: write short doc here
+//! This module is responsible for implementing handlers for Lanuage Server Protocol.
+//! The majority of requests are fulfilled by calling into the `ra_ide` crate.
 
 use std::{fmt::Write as _, io::Write as _};
 
@@ -164,7 +165,7 @@ pub fn handle_on_type_formatting(
 
     // in `ra_ide`, the `on_type` invariant is that
     // `text.char_at(position) == typed_char`.
-    position.offset = position.offset - TextUnit::of_char('.');
+    position.offset -= TextUnit::of_char('.');
     let char_typed = params.ch.chars().next().unwrap_or('\0');
 
     // We have an assist that inserts ` ` after typing `->` in `fn foo() ->{`,
diff --git a/crates/ra_lsp_server/src/main_loop/pending_requests.rs b/crates/ra_lsp_server/src/main_loop/pending_requests.rs
index e7ea7aa5b..2d2213464 100644
--- a/crates/ra_lsp_server/src/main_loop/pending_requests.rs
+++ b/crates/ra_lsp_server/src/main_loop/pending_requests.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Datastructures that keep track of inflight requests.
 
 use std::time::{Duration, Instant};
 
diff --git a/crates/ra_lsp_server/src/main_loop/subscriptions.rs b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
index 609b2adcc..b0bae90f5 100644
--- a/crates/ra_lsp_server/src/main_loop/subscriptions.rs
+++ b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Keeps track of file subscriptions.
 
 use ra_ide::FileId;
 use rustc_hash::FxHashSet;
diff --git a/crates/ra_lsp_server/src/markdown.rs b/crates/ra_lsp_server/src/markdown.rs
index f51fc4ade..76bef45cc 100644
--- a/crates/ra_lsp_server/src/markdown.rs
+++ b/crates/ra_lsp_server/src/markdown.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Transforms markdown
 
 pub(crate) fn format_docs(src: &str) -> String {
     let mut processed_lines = Vec::new();
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index 39361b7e8..b34e6f9b8 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Defines `rust-analyzer` specific custom messages.
 
 use lsp_types::{Location, Position, Range, TextDocumentIdentifier, Url};
 use rustc_hash::FxHashMap;
@@ -10,8 +10,9 @@ pub use lsp_types::{
     DidChangeWatchedFilesParams, DidChangeWatchedFilesRegistrationOptions,
     DocumentOnTypeFormattingParams, DocumentSymbolParams, DocumentSymbolResponse,
     FileSystemWatcher, Hover, InitializeResult, MessageType, PublishDiagnosticsParams,
-    ReferenceParams, Registration, RegistrationParams, ShowMessageParams, SignatureHelp,
-    TextDocumentEdit, TextDocumentPositionParams, TextEdit, WorkspaceEdit, WorkspaceSymbolParams,
+    ReferenceParams, Registration, RegistrationParams, SelectionRange, SelectionRangeParams,
+    ShowMessageParams, SignatureHelp, TextDocumentEdit, TextDocumentPositionParams, TextEdit,
+    WorkspaceEdit, WorkspaceSymbolParams,
 };
 
 pub enum AnalyzerStatus {}
@@ -67,28 +68,6 @@ pub struct ExpandMacroParams {
     pub position: Option<Position>,
 }
 
-pub enum SelectionRangeRequest {}
-
-impl Request for SelectionRangeRequest {
-    type Params = SelectionRangeParams;
-    type Result = Vec<SelectionRange>;
-    const METHOD: &'static str = "textDocument/selectionRange";
-}
-
-#[derive(Deserialize, Debug)]
-#[serde(rename_all = "camelCase")]
-pub struct SelectionRangeParams {
-    pub text_document: TextDocumentIdentifier,
-    pub positions: Vec<Position>,
-}
-
-#[derive(Serialize, Debug)]
-#[serde(rename_all = "camelCase")]
-pub struct SelectionRange {
-    pub range: Range,
-    pub parent: Option<Box<SelectionRange>>,
-}
-
 pub enum FindMatchingBrace {}
 
 impl Request for FindMatchingBrace {
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 16cc11e8c..5e53b0278 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -1,4 +1,7 @@
-//! FIXME: write short doc here
+//! The context or environment in which the language server functions.
+//! In our server implementation this is know as the `WorldState`.
+//!
+//! Each tick provides an immutable snapshot of the state as `WorldSnapshot`.
 
 use std::{
     path::{Path, PathBuf},
@@ -287,19 +290,15 @@ impl WorldSnapshot {
 ///
 /// When processing non-windows path, this is essentially the same as `Url::from_file_path`.
 fn url_from_path_with_drive_lowercasing(path: impl AsRef<Path>) -> Result<Url> {
-    let component_has_windows_drive = path
-        .as_ref()
-        .components()
-        .find(|comp| {
-            if let Component::Prefix(c) = comp {
-                match c.kind() {
-                    Prefix::Disk(_) | Prefix::VerbatimDisk(_) => return true,
-                    _ => return false,
-                }
+    let component_has_windows_drive = path.as_ref().components().any(|comp| {
+        if let Component::Prefix(c) = comp {
+            match c.kind() {
+                Prefix::Disk(_) | Prefix::VerbatimDisk(_) => return true,
+                _ => return false,
             }
-            false
-        })
-        .is_some();
+        }
+        false
+    });
 
     // VSCode expects drive letters to be lowercased, where rust will uppercase the drive letters.
     if component_has_windows_drive {