Send active diagnostics to LSP when requesting code actions. (#2005)

* Send active diagnostics to LSP when requesting code actions.

This allows for e.g. clangd to properly send the quickfix code actions
corresponding to those diagnostics as options.
The LSP spec v3.16.0 introduced an opaque `data` member that would allow
the server to persist arbitrary data between the diagnostic and the code
actions request, but this is not supported yet by this commit.

* Reuse existing range_to_lsp_range functionality

1 files changed, 22 insertions, 8 deletions

diff --git a/helix-term/src/commands/lsp.rs b/helix-term/src/commands/lsp.rs
index 1db57ecf..0a12ae39 100644
--- a/helix-term/src/commands/lsp.rs
+++ b/helix-term/src/commands/lsp.rs
@@ -1,6 +1,6 @@
 use helix_lsp::{
     block_on, lsp,
-    util::{lsp_pos_to_pos, lsp_range_to_range, range_to_lsp_range},
+    util::{diagnostic_to_lsp_diagnostic, lsp_pos_to_pos, lsp_range_to_range, range_to_lsp_range},
     OffsetEncoding,
 };
 
@@ -192,15 +192,29 @@ pub fn code_action(cx: &mut Context) {
 
     let language_server = language_server!(cx.editor, doc);
 
-    let range = range_to_lsp_range(
-        doc.text(),
-        doc.selection(view.id).primary(),
-        language_server.offset_encoding(),
-    );
-
-    let future = language_server.code_actions(doc.identifier(), range);
+    let selection_range = doc.selection(view.id).primary();
     let offset_encoding = language_server.offset_encoding();
 
+    let range = range_to_lsp_range(doc.text(), selection_range, offset_encoding);
+
+    let future = language_server.code_actions(
+        doc.identifier(),
+        range,
+        // Filter and convert overlapping diagnostics
+        lsp::CodeActionContext {
+            diagnostics: doc
+                .diagnostics()
+                .iter()
+                .filter(|&diag| {
+                    selection_range
+                        .overlaps(&helix_core::Range::new(diag.range.start, diag.range.end))
+                })
+                .map(|diag| diagnostic_to_lsp_diagnostic(doc.text(), diag, offset_encoding))
+                .collect(),
+            only: None,
+        },
+    );
+
     cx.callback(
         future,
         move |editor, compositor, response: Option<lsp::CodeActionResponse>| {