make path changes LSP spec conform (#8949)

Currently, helix implements operations which change the paths of files
incorrectly and inconsistently. This PR ensures that we do the following
whenever a buffer is renamed (`:move` and workspace edits)

* always send did_open/did_close notifications
* send will_rename/did_rename requests correctly
  * send them to all LSP servers not just those that are active for a
    buffer
  * also send these requests for paths that are not yet open in a buffer (if
    triggered from workspace edit).
  * only send these if the server registered interests in the path
* autodetect language, indent, line ending, ..

This PR also centralizes the infrastructure for path setting and
therefore `:w <path>` benefits from similar fixed (but without didRename)

helix-lsp/src/client.rs

@@ -1,4 +1,5 @@
 use crate::{
+    file_operations::FileOperationsInterest,
     find_lsp_workspace, jsonrpc,
     transport::{Payload, Transport},
     Call, Error, OffsetEncoding, Result,
@@ -9,20 +10,20 @@ use helix_loader::{self, VERSION_AND_GIT_HASH};
 use helix_stdx::path;
 use lsp::{
     notification::DidChangeWorkspaceFolders, CodeActionCapabilityResolveSupport,
-    DidChangeWorkspaceFoldersParams, OneOf, PositionEncodingKind, SignatureHelp, WorkspaceFolder,
+    DidChangeWorkspaceFoldersParams, OneOf, PositionEncodingKind, SignatureHelp, Url,
-    WorkspaceFoldersChangeEvent,
+    WorkspaceFolder, WorkspaceFoldersChangeEvent,
 };
 use lsp_types as lsp;
 use parking_lot::Mutex;
 use serde::Deserialize;
 use serde_json::Value;
-use std::future::Future;
-use std::process::Stdio;
 use std::sync::{
     atomic::{AtomicU64, Ordering},
     Arc,
 };
 use std::{collections::HashMap, path::PathBuf};
+use std::{future::Future, sync::OnceLock};
+use std::{path::Path, process::Stdio};
 use tokio::{
     io::{BufReader, BufWriter},
     process::{Child, Command},
@@ -51,6 +52,7 @@ pub struct Client {
     server_tx: UnboundedSender<Payload>,
     request_counter: AtomicU64,
     pub(crate) capabilities: OnceCell<lsp::ServerCapabilities>,
+    pub(crate) file_operation_interest: OnceLock<FileOperationsInterest>,
     config: Option<Value>,
     root_path: std::path::PathBuf,
     root_uri: Option<lsp::Url>,
@@ -233,6 +235,7 @@ impl Client {
             server_tx,
             request_counter: AtomicU64::new(0),
             capabilities: OnceCell::new(),
+            file_operation_interest: OnceLock::new(),
             config,
             req_timeout,
             root_path,
@@ -278,6 +281,11 @@ impl Client {
             .expect("language server not yet initialized!")
     }
 
+    pub(crate) fn file_operations_intests(&self) -> &FileOperationsInterest {
+        self.file_operation_interest
+            .get_or_init(|| FileOperationsInterest::new(self.capabilities()))
+    }
+
     /// Client has to be initialized otherwise this function panics
     #[inline]
     pub fn supports_feature(&self, feature: LanguageServerFeature) -> bool {
@@ -717,27 +725,27 @@ impl Client {
         })
     }
 
-    pub fn prepare_file_rename(
+    pub fn will_rename(
         &self,
-        old_uri: &lsp::Url,
+        old_path: &Path,
-        new_uri: &lsp::Url,
+        new_path: &Path,
+        is_dir: bool,
     ) -> Option<impl Future<Output = Result<lsp::WorkspaceEdit>>> {
-        let capabilities = self.capabilities.get().unwrap();
+        let capabilities = self.file_operations_intests();
-
+        if !capabilities.will_rename.has_interest(old_path, is_dir) {
-        // Return early if the server does not support willRename feature
+            return None;
-        match &capabilities.workspace {
-            Some(workspace) => match &workspace.file_operations {
-                Some(op) => {
-                    op.will_rename.as_ref()?;
-                }
-                _ => return None,
-            },
-            _ => return None,
         }
-
+        let url_from_path = |path| {
+            let url = if is_dir {
+                Url::from_directory_path(path)
+            } else {
+                Url::from_file_path(path)
+            };
+            Some(url.ok()?.to_string())
+        };
         let files = vec![lsp::FileRename {
-            old_uri: old_uri.to_string(),
+            old_uri: url_from_path(old_path)?,
-            new_uri: new_uri.to_string(),
+            new_uri: url_from_path(new_path)?,
         }];
         let request = self.call_with_timeout::<lsp::request::WillRenameFiles>(
             lsp::RenameFilesParams { files },
@@ -751,27 +759,28 @@ impl Client {
         })
     }
 
-    pub fn did_file_rename(
+    pub fn did_rename(
         &self,
-        old_uri: &lsp::Url,
+        old_path: &Path,
-        new_uri: &lsp::Url,
+        new_path: &Path,
+        is_dir: bool,
     ) -> Option<impl Future<Output = std::result::Result<(), Error>>> {
-        let capabilities = self.capabilities.get().unwrap();
+        let capabilities = self.file_operations_intests();
-
+        if !capabilities.did_rename.has_interest(new_path, is_dir) {
-        // Return early if the server does not support DidRename feature
+            return None;
-        match &capabilities.workspace {
-            Some(workspace) => match &workspace.file_operations {
-                Some(op) => {
-                    op.did_rename.as_ref()?;
-                }
-                _ => return None,
-            },
-            _ => return None,
         }
+        let url_from_path = |path| {
+            let url = if is_dir {
+                Url::from_directory_path(path)
+            } else {
+                Url::from_file_path(path)
+            };
+            Some(url.ok()?.to_string())
+        };
 
         let files = vec![lsp::FileRename {
-            old_uri: old_uri.to_string(),
+            old_uri: url_from_path(old_path)?,
-            new_uri: new_uri.to_string(),
+            new_uri: url_from_path(new_path)?,
         }];
         Some(self.notify::<lsp::notification::DidRenameFiles>(lsp::RenameFilesParams { files }))
     }

helix-lsp/src/file_operations.rs

@@ -0,0 +1,105 @@
+use std::path::Path;
+
+use globset::{GlobBuilder, GlobSet};
+
+use crate::lsp;
+
+#[derive(Default, Debug)]
+pub(crate) struct FileOperationFilter {
+    dir_globs: GlobSet,
+    file_globs: GlobSet,
+}
+
+impl FileOperationFilter {
+    fn new(capability: Option<&lsp::FileOperationRegistrationOptions>) -> FileOperationFilter {
+        let Some(cap) = capability else {
+            return FileOperationFilter::default();
+        };
+        let mut dir_globs = GlobSet::builder();
+        let mut file_globs = GlobSet::builder();
+        for filter in &cap.filters {
+            // TODO: support other url schemes
+            let is_non_file_schema = filter
+                .scheme
+                .as_ref()
+                .is_some_and(|schema| schema != "file");
+            if is_non_file_schema {
+                continue;
+            }
+            let ignore_case = filter
+                .pattern
+                .options
+                .as_ref()
+                .and_then(|opts| opts.ignore_case)
+                .unwrap_or(false);
+            let mut glob_builder = GlobBuilder::new(&filter.pattern.glob);
+            glob_builder.case_insensitive(!ignore_case);
+            let glob = match glob_builder.build() {
+                Ok(glob) => glob,
+                Err(err) => {
+                    log::error!("invalid glob send by LS: {err}");
+                    continue;
+                }
+            };
+            match filter.pattern.matches {
+                Some(lsp::FileOperationPatternKind::File) => {
+                    file_globs.add(glob);
+                }
+                Some(lsp::FileOperationPatternKind::Folder) => {
+                    dir_globs.add(glob);
+                }
+                None => {
+                    file_globs.add(glob.clone());
+                    dir_globs.add(glob);
+                }
+            };
+        }
+        let file_globs = file_globs.build().unwrap_or_else(|err| {
+            log::error!("invalid globs send by LS: {err}");
+            GlobSet::empty()
+        });
+        let dir_globs = dir_globs.build().unwrap_or_else(|err| {
+            log::error!("invalid globs send by LS: {err}");
+            GlobSet::empty()
+        });
+        FileOperationFilter {
+            dir_globs,
+            file_globs,
+        }
+    }
+
+    pub(crate) fn has_interest(&self, path: &Path, is_dir: bool) -> bool {
+        if is_dir {
+            self.dir_globs.is_match(path)
+        } else {
+            self.file_globs.is_match(path)
+        }
+    }
+}
+
+#[derive(Default, Debug)]
+pub(crate) struct FileOperationsInterest {
+    // TODO: support other notifications
+    // did_create: FileOperationFilter,
+    // will_create: FileOperationFilter,
+    pub did_rename: FileOperationFilter,
+    pub will_rename: FileOperationFilter,
+    // did_delete: FileOperationFilter,
+    // will_delete: FileOperationFilter,
+}
+
+impl FileOperationsInterest {
+    pub fn new(capabilities: &lsp::ServerCapabilities) -> FileOperationsInterest {
+        let capabilities = capabilities
+            .workspace
+            .as_ref()
+            .and_then(|capabilities| capabilities.file_operations.as_ref());
+        let Some(capabilities) = capabilities else {
+            return FileOperationsInterest::default();
+        };
+        FileOperationsInterest {
+            did_rename: FileOperationFilter::new(capabilities.did_rename.as_ref()),
+            will_rename: FileOperationFilter::new(capabilities.will_rename.as_ref()),
+        }
+    }
+}

helix-lsp/src/lib.rs

@@ -1,5 +1,6 @@
 mod client;
 pub mod file_event;
+mod file_operations;
 pub mod jsonrpc;
 pub mod snippet;
 mod transport;

helix-term/src/application.rs

@@ -21,7 +21,6 @@ use tui::backend::Backend;
 
 use crate::{
     args::Args,
-    commands::apply_workspace_edit,
     compositor::{Compositor, Event},
     config::Config,
     handlers,
@@ -573,26 +572,8 @@ impl Application {
         let lines = doc_save_event.text.len_lines();
         let bytes = doc_save_event.text.len_bytes();
 
-        if doc.path() != Some(&doc_save_event.path) {
+        self.editor
-            doc.set_path(Some(&doc_save_event.path));
+            .set_doc_path(doc_save_event.doc_id, &doc_save_event.path);
-
-            let loader = self.editor.syn_loader.clone();
-
-            // borrowing the same doc again to get around the borrow checker
-            let doc = doc_mut!(self.editor, &doc_save_event.doc_id);
-            let id = doc.id();
-            doc.detect_language(loader);
-            self.editor.refresh_language_servers(id);
-            // and again a borrow checker workaround...
-            let doc = doc_mut!(self.editor, &doc_save_event.doc_id);
-            let diagnostics = Editor::doc_diagnostics(
-                &self.editor.language_servers,
-                &self.editor.diagnostics,
-                doc,
-            );
-            doc.replace_diagnostics(diagnostics, &[], None);
-        }
-
         // TODO: fix being overwritten by lsp
         self.editor.set_status(format!(
             "'{}' written, {}L {}B",
@@ -1011,11 +992,9 @@ impl Application {
                         let language_server = language_server!();
                         if language_server.is_initialized() {
                             let offset_encoding = language_server.offset_encoding();
-                            let res = apply_workspace_edit(
+                            let res = self
-                                &mut self.editor,
+                                .editor
-                                offset_encoding,
+                                .apply_workspace_edit(offset_encoding, &params.edit);
-                                &params.edit,
-                            );
 
                             Ok(json!(lsp::ApplyWorkspaceEditResponse {
                                 applied: res.is_ok(),

helix-term/src/commands/lsp.rs

@@ -726,8 +726,7 @@ pub fn code_action(cx: &mut Context) {
                             resolved_code_action.as_ref().unwrap_or(code_action);
 
                         if let Some(ref workspace_edit) = resolved_code_action.edit {
-                            log::debug!("edit: {:?}", workspace_edit);
+                            let _ = editor.apply_workspace_edit(offset_encoding, workspace_edit);
-                            let _ = apply_workspace_edit(editor, offset_encoding, workspace_edit);
                         }
 
                         // if code action provides both edit and command first the edit
@@ -787,63 +786,6 @@ pub fn execute_lsp_command(editor: &mut Editor, language_server_id: usize, cmd:
     });
 }
 
-pub fn apply_document_resource_op(op: &lsp::ResourceOp) -> std::io::Result<()> {
-    use lsp::ResourceOp;
-    use std::fs;
-    match op {
-        ResourceOp::Create(op) => {
-            let path = op.uri.to_file_path().unwrap();
-            let ignore_if_exists = op.options.as_ref().map_or(false, |options| {
-                !options.overwrite.unwrap_or(false) && options.ignore_if_exists.unwrap_or(false)
-            });
-            if ignore_if_exists && path.exists() {
-                Ok(())
-            } else {
-                // Create directory if it does not exist
-                if let Some(dir) = path.parent() {
-                    if !dir.is_dir() {
-                        fs::create_dir_all(dir)?;
-                    }
-                }
-
-                fs::write(&path, [])
-            }
-        }
-        ResourceOp::Delete(op) => {
-            let path = op.uri.to_file_path().unwrap();
-            if path.is_dir() {
-                let recursive = op
-                    .options
-                    .as_ref()
-                    .and_then(|options| options.recursive)
-                    .unwrap_or(false);
-
-                if recursive {
-                    fs::remove_dir_all(&path)
-                } else {
-                    fs::remove_dir(&path)
-                }
-            } else if path.is_file() {
-                fs::remove_file(&path)
-            } else {
-                Ok(())
-            }
-        }
-        ResourceOp::Rename(op) => {
-            let from = op.old_uri.to_file_path().unwrap();
-            let to = op.new_uri.to_file_path().unwrap();
-            let ignore_if_exists = op.options.as_ref().map_or(false, |options| {
-                !options.overwrite.unwrap_or(false) && options.ignore_if_exists.unwrap_or(false)
-            });
-            if ignore_if_exists && to.exists() {
-                Ok(())
-            } else {
-                fs::rename(from, &to)
-            }
-        }
-    }
-}
-
 #[derive(Debug)]
 pub struct ApplyEditError {
     pub kind: ApplyEditErrorKind,
@@ -871,142 +813,6 @@ impl ToString for ApplyEditErrorKind {
     }
 }
 
-///TODO make this transactional (and set failureMode to transactional)
-pub fn apply_workspace_edit(
-    editor: &mut Editor,
-    offset_encoding: OffsetEncoding,
-    workspace_edit: &lsp::WorkspaceEdit,
-) -> Result<(), ApplyEditError> {
-    let mut apply_edits = |uri: &helix_lsp::Url,
-                           version: Option<i32>,
-                           text_edits: Vec<lsp::TextEdit>|
-     -> Result<(), ApplyEditErrorKind> {
-        let path = match uri.to_file_path() {
-            Ok(path) => path,
-            Err(_) => {
-                let err = format!("unable to convert URI to filepath: {}", uri);
-                log::error!("{}", err);
-                editor.set_error(err);
-                return Err(ApplyEditErrorKind::UnknownURISchema);
-            }
-        };
-
-        let doc_id = match editor.open(&path, Action::Load) {
-            Ok(doc_id) => doc_id,
-            Err(err) => {
-                let err = format!("failed to open document: {}: {}", uri, err);
-                log::error!("{}", err);
-                editor.set_error(err);
-                return Err(ApplyEditErrorKind::FileNotFound);
-            }
-        };
-
-        let doc = doc!(editor, &doc_id);
-        if let Some(version) = version {
-            if version != doc.version() {
-                let err = format!("outdated workspace edit for {path:?}");
-                log::error!("{err}, expected {} but got {version}", doc.version());
-                editor.set_error(err);
-                return Err(ApplyEditErrorKind::DocumentChanged);
-            }
-        }
-
-        // Need to determine a view for apply/append_changes_to_history
-        let view_id = editor.get_synced_view_id(doc_id);
-        let doc = doc_mut!(editor, &doc_id);
-
-        let transaction = helix_lsp::util::generate_transaction_from_edits(
-            doc.text(),
-            text_edits,
-            offset_encoding,
-        );
-        let view = view_mut!(editor, view_id);
-        doc.apply(&transaction, view.id);
-        doc.append_changes_to_history(view);
-        Ok(())
-    };
-
-    if let Some(ref document_changes) = workspace_edit.document_changes {
-        match document_changes {
-            lsp::DocumentChanges::Edits(document_edits) => {
-                for (i, document_edit) in document_edits.iter().enumerate() {
-                    let edits = document_edit
-                        .edits
-                        .iter()
-                        .map(|edit| match edit {
-                            lsp::OneOf::Left(text_edit) => text_edit,
-                            lsp::OneOf::Right(annotated_text_edit) => {
-                                &annotated_text_edit.text_edit
-                            }
-                        })
-                        .cloned()
-                        .collect();
-                    apply_edits(
-                        &document_edit.text_document.uri,
-                        document_edit.text_document.version,
-                        edits,
-                    )
-                    .map_err(|kind| ApplyEditError {
-                        kind,
-                        failed_change_idx: i,
-                    })?;
-                }
-            }
-            lsp::DocumentChanges::Operations(operations) => {
-                log::debug!("document changes - operations: {:?}", operations);
-                for (i, operation) in operations.iter().enumerate() {
-                    match operation {
-                        lsp::DocumentChangeOperation::Op(op) => {
-                            apply_document_resource_op(op).map_err(|io| ApplyEditError {
-                                kind: ApplyEditErrorKind::IoError(io),
-                                failed_change_idx: i,
-                            })?;
-                        }
-
-                        lsp::DocumentChangeOperation::Edit(document_edit) => {
-                            let edits = document_edit
-                                .edits
-                                .iter()
-                                .map(|edit| match edit {
-                                    lsp::OneOf::Left(text_edit) => text_edit,
-                                    lsp::OneOf::Right(annotated_text_edit) => {
-                                        &annotated_text_edit.text_edit
-                                    }
-                                })
-                                .cloned()
-                                .collect();
-                            apply_edits(
-                                &document_edit.text_document.uri,
-                                document_edit.text_document.version,
-                                edits,
-                            )
-                            .map_err(|kind| ApplyEditError {
-                                kind,
-                                failed_change_idx: i,
-                            })?;
-                        }
-                    }
-                }
-            }
-        }
-
-        return Ok(());
-    }
-
-    if let Some(ref changes) = workspace_edit.changes {
-        log::debug!("workspace changes: {:?}", changes);
-        for (i, (uri, text_edits)) in changes.iter().enumerate() {
-            let text_edits = text_edits.to_vec();
-            apply_edits(uri, None, text_edits).map_err(|kind| ApplyEditError {
-                kind,
-                failed_change_idx: i,
-            })?;
-        }
-    }
-
-    Ok(())
-}
-
 /// Precondition: `locations` should be non-empty.
 fn goto_impl(
     editor: &mut Editor,
@@ -1263,7 +1069,7 @@ pub fn rename_symbol(cx: &mut Context) {
 
                 match block_on(future) {
                     Ok(edits) => {
-                        let _ = apply_workspace_edit(cx.editor, offset_encoding, &edits);
+                        let _ = cx.editor.apply_workspace_edit(offset_encoding, &edits);
                     }
                     Err(err) => cx.editor.set_error(err.to_string()),
                 }

helix-term/src/commands/typed.rs

@@ -8,7 +8,6 @@ use super::*;
 use helix_core::fuzzy::fuzzy_match;
 use helix_core::indent::MAX_INDENT;
 use helix_core::{encoding, line_ending, shellwords::Shellwords};
-use helix_lsp::{OffsetEncoding, Url};
 use helix_view::document::DEFAULT_LANGUAGE_NAME;
 use helix_view::editor::{Action, CloseError, ConfigEvent};
 use serde_json::Value;
@@ -2404,67 +2403,14 @@ fn move_buffer(
 
     ensure!(args.len() == 1, format!(":move takes one argument"));
     let doc = doc!(cx.editor);
-
-    let new_path =
-        helix_stdx::path::canonicalize(&PathBuf::from(args.first().unwrap().to_string()));
     let old_path = doc
         .path()
-        .ok_or_else(|| anyhow!("Scratch buffer cannot be moved. Use :write instead"))?
+        .context("Scratch buffer cannot be moved. Use :write instead")?
         .clone();
-    let old_path_as_url = doc.url().unwrap();
+    let new_path = args.first().unwrap().to_string();
-    let new_path_as_url = Url::from_file_path(&new_path).unwrap();
+    if let Err(err) = cx.editor.move_path(&old_path, new_path.as_ref()) {
-
+        bail!("Could not move file: {err}");
-    let edits: Vec<(
-        helix_lsp::Result<helix_lsp::lsp::WorkspaceEdit>,
-        OffsetEncoding,
-        String,
-    )> = doc
-        .language_servers()
-        .map(|lsp| {
-            (
-                lsp.prepare_file_rename(&old_path_as_url, &new_path_as_url),
-                lsp.offset_encoding(),
-                lsp.name().to_owned(),
-            )
-        })
-        .filter(|(f, _, _)| f.is_some())
-        .map(|(f, encoding, name)| (helix_lsp::block_on(f.unwrap()), encoding, name))
-        .collect();
-
-    for (lsp_reply, encoding, name) in edits {
-        match lsp_reply {
-            Ok(edit) => {
-                if let Err(e) = apply_workspace_edit(cx.editor, encoding, &edit) {
-                    log::error!(
-                        ":move command failed to apply edits from lsp {}: {:?}",
-                        name,
-                        e
-                    );
-                };
-            }
-            Err(e) => {
-                log::error!("LSP {} failed to treat willRename request: {:?}", name, e);
-            }
-        };
     }
-
-    let doc = doc_mut!(cx.editor);
-
-    doc.set_path(Some(new_path.as_path()));
-    if let Err(e) = std::fs::rename(&old_path, &new_path) {
-        doc.set_path(Some(old_path.as_path()));
-        bail!("Could not move file: {}", e);
-    };
-
-    doc.language_servers().for_each(|lsp| {
-        lsp.did_file_rename(&old_path_as_url, &new_path_as_url);
-    });
-
-    cx.editor
-        .language_servers
-        .file_event_handler
-        .file_changed(new_path);
-
     Ok(())
 }
 

helix-view/src/document.rs

@@ -1041,6 +1041,9 @@ impl Document {
         self.encoding
     }
 
+    /// sets the document path without sending events to various
+    /// observers (like LSP), in most cases `Editor::set_doc_path`
+    /// should be used instead
     pub fn set_path(&mut self, path: Option<&Path>) {
         let path = path.map(helix_stdx::path::canonicalize);
 

helix-view/src/editor.rs

@@ -23,7 +23,8 @@ use std::{
     borrow::Cow,
     cell::Cell,
     collections::{BTreeMap, HashMap},
-    io::stdin,
+    fs,
+    io::{self, stdin},
     num::NonZeroUsize,
     path::{Path, PathBuf},
     pin::Pin,
@@ -45,6 +46,7 @@ use helix_core::{
 };
 use helix_dap as dap;
 use helix_lsp::lsp;
+use helix_stdx::path::canonicalize;
 
 use serde::{ser::SerializeMap, Deserialize, Deserializer, Serialize, Serializer};
 
@@ -1215,6 +1217,90 @@ impl Editor {
         self.launch_language_servers(doc_id)
     }
 
+    /// moves/renames a path, invoking any event handlers (currently only lsp)
+    /// and calling `set_doc_path` if the file is open in the editor
+    pub fn move_path(&mut self, old_path: &Path, new_path: &Path) -> io::Result<()> {
+        let new_path = canonicalize(new_path);
+        // sanity check
+        if old_path == new_path {
+            return Ok(());
+        }
+        let is_dir = old_path.is_dir();
+        let language_servers: Vec<_> = self
+            .language_servers
+            .iter_clients()
+            .filter(|client| client.is_initialized())
+            .cloned()
+            .collect();
+        for language_server in language_servers {
+            let Some(request) = language_server.will_rename(old_path, &new_path, is_dir) else {
+                continue;
+            };
+            let edit = match helix_lsp::block_on(request) {
+                Ok(edit) => edit,
+                Err(err) => {
+                    log::error!("invalid willRename response: {err:?}");
+                    continue;
+                }
+            };
+            if let Err(err) = self.apply_workspace_edit(language_server.offset_encoding(), &edit) {
+                log::error!("failed to apply workspace edit: {err:?}")
+            }
+        }
+        fs::rename(old_path, &new_path)?;
+        if let Some(doc) = self.document_by_path(old_path) {
+            self.set_doc_path(doc.id(), &new_path);
+        }
+        let is_dir = new_path.is_dir();
+        for ls in self.language_servers.iter_clients() {
+            if let Some(notification) = ls.did_rename(old_path, &new_path, is_dir) {
+                tokio::spawn(notification);
+            };
+        }
+        self.language_servers
+            .file_event_handler
+            .file_changed(old_path.to_owned());
+        self.language_servers
+            .file_event_handler
+            .file_changed(new_path);
+        Ok(())
+    }
+
+    pub fn set_doc_path(&mut self, doc_id: DocumentId, path: &Path) {
+        let doc = doc_mut!(self, &doc_id);
+        let old_path = doc.path();
+
+        if let Some(old_path) = old_path {
+            // sanity check, should not occur but some callers (like an LSP) may
+            // create bogus calls
+            if old_path == path {
+                return;
+            }
+            // if we are open in LSPs send did_close notification
+            for language_server in doc.language_servers() {
+                tokio::spawn(language_server.text_document_did_close(doc.identifier()));
+            }
+        }
+        // we need to clear the list of language servers here so that
+        // refresh_doc_language/refresh_language_servers doesn't resend
+        // text_document_did_close. Since we called `text_document_did_close`
+        // we have fully unregistered this document from its LS
+        doc.language_servers.clear();
+        doc.set_path(Some(path));
+        self.refresh_doc_language(doc_id)
+    }
+
+    pub fn refresh_doc_language(&mut self, doc_id: DocumentId) {
+        let loader = self.syn_loader.clone();
+        let doc = doc_mut!(self, &doc_id);
+        doc.detect_language(loader);
+        doc.detect_indent_and_line_ending();
+        self.refresh_language_servers(doc_id);
+        let doc = doc_mut!(self, &doc_id);
+        let diagnostics = Editor::doc_diagnostics(&self.language_servers, &self.diagnostics, doc);
+        doc.replace_diagnostics(diagnostics, &[], None);
+    }
+
     /// Launch a language server for a given document
     fn launch_language_servers(&mut self, doc_id: DocumentId) {
         if !self.config().lsp.enable {
@@ -1257,7 +1343,7 @@ impl Editor {
                 .collect::<HashMap<_, _>>()
         });
 
-        if language_servers.is_empty() {
+        if language_servers.is_empty() && doc.language_servers.is_empty() {
             return;
         }
 

helix-view/src/handlers/lsp.rs

@@ -1,4 +1,8 @@
+use crate::editor::Action;
+use crate::Editor;
 use crate::{DocumentId, ViewId};
+use helix_lsp::util::generate_transaction_from_edits;
+use helix_lsp::{lsp, OffsetEncoding};
 
 pub enum CompletionEvent {
     /// Auto completion was triggered by typing a word char
@@ -39,3 +43,228 @@ pub enum SignatureHelpEvent {
     Cancel,
     RequestComplete { open: bool },
 }
+
+#[derive(Debug)]
+pub struct ApplyEditError {
+    pub kind: ApplyEditErrorKind,
+    pub failed_change_idx: usize,
+}
+
+#[derive(Debug)]
+pub enum ApplyEditErrorKind {
+    DocumentChanged,
+    FileNotFound,
+    UnknownURISchema,
+    IoError(std::io::Error),
+    // TODO: check edits before applying and propagate failure
+    // InvalidEdit,
+}
+
+impl ToString for ApplyEditErrorKind {
+    fn to_string(&self) -> String {
+        match self {
+            ApplyEditErrorKind::DocumentChanged => "document has changed".to_string(),
+            ApplyEditErrorKind::FileNotFound => "file not found".to_string(),
+            ApplyEditErrorKind::UnknownURISchema => "URI schema not supported".to_string(),
+            ApplyEditErrorKind::IoError(err) => err.to_string(),
+        }
+    }
+}
+
+impl Editor {
+    fn apply_text_edits(
+        &mut self,
+        uri: &helix_lsp::Url,
+        version: Option<i32>,
+        text_edits: Vec<lsp::TextEdit>,
+        offset_encoding: OffsetEncoding,
+    ) -> Result<(), ApplyEditErrorKind> {
+        let path = match uri.to_file_path() {
+            Ok(path) => path,
+            Err(_) => {
+                let err = format!("unable to convert URI to filepath: {}", uri);
+                log::error!("{}", err);
+                self.set_error(err);
+                return Err(ApplyEditErrorKind::UnknownURISchema);
+            }
+        };
+
+        let doc_id = match self.open(&path, Action::Load) {
+            Ok(doc_id) => doc_id,
+            Err(err) => {
+                let err = format!("failed to open document: {}: {}", uri, err);
+                log::error!("{}", err);
+                self.set_error(err);
+                return Err(ApplyEditErrorKind::FileNotFound);
+            }
+        };
+
+        let doc = doc_mut!(self, &doc_id);
+        if let Some(version) = version {
+            if version != doc.version() {
+                let err = format!("outdated workspace edit for {path:?}");
+                log::error!("{err}, expected {} but got {version}", doc.version());
+                self.set_error(err);
+                return Err(ApplyEditErrorKind::DocumentChanged);
+            }
+        }
+
+        // Need to determine a view for apply/append_changes_to_history
+        let view_id = self.get_synced_view_id(doc_id);
+        let doc = doc_mut!(self, &doc_id);
+
+        let transaction = generate_transaction_from_edits(doc.text(), text_edits, offset_encoding);
+        let view = view_mut!(self, view_id);
+        doc.apply(&transaction, view.id);
+        doc.append_changes_to_history(view);
+        Ok(())
+    }
+
+    // TODO make this transactional (and set failureMode to transactional)
+    pub fn apply_workspace_edit(
+        &mut self,
+        offset_encoding: OffsetEncoding,
+        workspace_edit: &lsp::WorkspaceEdit,
+    ) -> Result<(), ApplyEditError> {
+        if let Some(ref document_changes) = workspace_edit.document_changes {
+            match document_changes {
+                lsp::DocumentChanges::Edits(document_edits) => {
+                    for (i, document_edit) in document_edits.iter().enumerate() {
+                        let edits = document_edit
+                            .edits
+                            .iter()
+                            .map(|edit| match edit {
+                                lsp::OneOf::Left(text_edit) => text_edit,
+                                lsp::OneOf::Right(annotated_text_edit) => {
+                                    &annotated_text_edit.text_edit
+                                }
+                            })
+                            .cloned()
+                            .collect();
+                        self.apply_text_edits(
+                            &document_edit.text_document.uri,
+                            document_edit.text_document.version,
+                            edits,
+                            offset_encoding,
+                        )
+                        .map_err(|kind| ApplyEditError {
+                            kind,
+                            failed_change_idx: i,
+                        })?;
+                    }
+                }
+                lsp::DocumentChanges::Operations(operations) => {
+                    log::debug!("document changes - operations: {:?}", operations);
+                    for (i, operation) in operations.iter().enumerate() {
+                        match operation {
+                            lsp::DocumentChangeOperation::Op(op) => {
+                                self.apply_document_resource_op(op).map_err(|io| {
+                                    ApplyEditError {
+                                        kind: ApplyEditErrorKind::IoError(io),
+                                        failed_change_idx: i,
+                                    }
+                                })?;
+                            }
+
+                            lsp::DocumentChangeOperation::Edit(document_edit) => {
+                                let edits = document_edit
+                                    .edits
+                                    .iter()
+                                    .map(|edit| match edit {
+                                        lsp::OneOf::Left(text_edit) => text_edit,
+                                        lsp::OneOf::Right(annotated_text_edit) => {
+                                            &annotated_text_edit.text_edit
+                                        }
+                                    })
+                                    .cloned()
+                                    .collect();
+                                self.apply_text_edits(
+                                    &document_edit.text_document.uri,
+                                    document_edit.text_document.version,
+                                    edits,
+                                    offset_encoding,
+                                )
+                                .map_err(|kind| {
+                                    ApplyEditError {
+                                        kind,
+                                        failed_change_idx: i,
+                                    }
+                                })?;
+                            }
+                        }
+                    }
+                }
+            }
+
+            return Ok(());
+        }
+
+        if let Some(ref changes) = workspace_edit.changes {
+            log::debug!("workspace changes: {:?}", changes);
+            for (i, (uri, text_edits)) in changes.iter().enumerate() {
+                let text_edits = text_edits.to_vec();
+                self.apply_text_edits(uri, None, text_edits, offset_encoding)
+                    .map_err(|kind| ApplyEditError {
+                        kind,
+                        failed_change_idx: i,
+                    })?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn apply_document_resource_op(&mut self, op: &lsp::ResourceOp) -> std::io::Result<()> {
+        use lsp::ResourceOp;
+        use std::fs;
+        match op {
+            ResourceOp::Create(op) => {
+                let path = op.uri.to_file_path().unwrap();
+                let ignore_if_exists = op.options.as_ref().map_or(false, |options| {
+                    !options.overwrite.unwrap_or(false) && options.ignore_if_exists.unwrap_or(false)
+                });
+                if !ignore_if_exists || !path.exists() {
+                    // Create directory if it does not exist
+                    if let Some(dir) = path.parent() {
+                        if !dir.is_dir() {
+                            fs::create_dir_all(dir)?;
+                        }
+                    }
+
+                    fs::write(&path, [])?;
+                    self.language_servers.file_event_handler.file_changed(path);
+                }
+            }
+            ResourceOp::Delete(op) => {
+                let path = op.uri.to_file_path().unwrap();
+                if path.is_dir() {
+                    let recursive = op
+                        .options
+                        .as_ref()
+                        .and_then(|options| options.recursive)
+                        .unwrap_or(false);
+
+                    if recursive {
+                        fs::remove_dir_all(&path)?
+                    } else {
+                        fs::remove_dir(&path)?
+                    }
+                    self.language_servers.file_event_handler.file_changed(path);
+                } else if path.is_file() {
+                    fs::remove_file(&path)?;
+                }
+            }
+            ResourceOp::Rename(op) => {
+                let from = op.old_uri.to_file_path().unwrap();
+                let to = op.new_uri.to_file_path().unwrap();
+                let ignore_if_exists = op.options.as_ref().map_or(false, |options| {
+                    !options.overwrite.unwrap_or(false) && options.ignore_if_exists.unwrap_or(false)
+                });
+                if !ignore_if_exists || !to.exists() {
+                    self.move_path(&from, &to)?;
+                }
+            }
+        }
+        Ok(())
+    }
+}