Merge #8054

8054: Item movers r=matklad a=ivan770

Closes #6823

https://user-images.githubusercontent.com/14003886/111331579-b4f43480-8679-11eb-9af0-e4dabacc4923.mp4

Implementation issues:
- [ ] Most of items are non-movable, since _movability_ of any item has to be determined manually. Common ones are movable though
- [x] Cursor should move with the item

Co-authored-by: ivan770 <leshenko.ivan770@gmail.com>

crates/rust-analyzer/src/handlers.rs

@@ -1427,6 +1427,25 @@ pub(crate) fn handle_open_cargo_toml(
     Ok(Some(res))
 }
 
+pub(crate) fn handle_move_item(
+    snap: GlobalStateSnapshot,
+    params: lsp_ext::MoveItemParams,
+) -> Result<Option<lsp_types::TextDocumentEdit>> {
+    let _p = profile::span("handle_move_item");
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let range = from_proto::file_range(&snap, params.text_document, params.range)?;
+
+    let direction = match params.direction {
+        lsp_ext::MoveItemDirection::Up => ide::Direction::Up,
+        lsp_ext::MoveItemDirection::Down => ide::Direction::Down,
+    };
+
+    match snap.analysis.move_item(range, direction)? {
+        Some(text_edit) => Ok(Some(to_proto::text_document_edit(&snap, file_id, text_edit)?)),
+        None => Ok(None),
+    }
+}
+
 fn to_command_link(command: lsp_types::Command, tooltip: String) -> lsp_ext::CommandLink {
     lsp_ext::CommandLink { tooltip: Some(tooltip), command }
 }

crates/rust-analyzer/src/lsp_ext.rs

@@ -402,3 +402,25 @@ pub(crate) enum CodeLensResolveData {
 pub fn supports_utf8(caps: &lsp_types::ClientCapabilities) -> bool {
     caps.offset_encoding.as_deref().unwrap_or_default().iter().any(|it| it == "utf-8")
 }
+
+pub enum MoveItem {}
+
+impl Request for MoveItem {
+    type Params = MoveItemParams;
+    type Result = Option<lsp_types::TextDocumentEdit>;
+    const METHOD: &'static str = "experimental/moveItem";
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct MoveItemParams {
+    pub direction: MoveItemDirection,
+    pub text_document: TextDocumentIdentifier,
+    pub range: Range,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub enum MoveItemDirection {
+    Up,
+    Down,
+}

crates/rust-analyzer/src/main_loop.rs

@@ -504,6 +504,7 @@ impl GlobalState {
             .on::<lsp_ext::HoverRequest>(handlers::handle_hover)
             .on::<lsp_ext::ExternalDocs>(handlers::handle_open_docs)
             .on::<lsp_ext::OpenCargoToml>(handlers::handle_open_cargo_toml)
+            .on::<lsp_ext::MoveItem>(handlers::handle_move_item)
             .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)
             .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)
             .on::<lsp_types::request::WorkspaceSymbol>(handlers::handle_workspace_symbol)

crates/rust-analyzer/src/to_proto.rs

@@ -658,6 +658,18 @@ pub(crate) fn goto_definition_response(
     }
 }
 
+pub(crate) fn text_document_edit(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    edit: TextEdit,
+) -> Result<lsp_types::TextDocumentEdit> {
+    let text_document = optional_versioned_text_document_identifier(snap, file_id);
+    let line_index = snap.file_line_index(file_id)?;
+    let edits =
+        edit.into_iter().map(|it| lsp_types::OneOf::Left(text_edit(&line_index, it))).collect();
+    Ok(lsp_types::TextDocumentEdit { text_document, edits })
+}
+
 pub(crate) fn snippet_text_document_edit(
     snap: &GlobalStateSnapshot,
     is_snippet: bool,