lsp: Check bounds when converting lsp positions (#204)

* lsp: Make position conversion funcs return `Option`

* Add tests

* Fixes

* Revert pos_to_lsp_pos to panic

2 files changed, 25 insertions, 13 deletions

diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index bf829f2c..3d043441 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -178,7 +178,7 @@ impl Application {
                             let diagnostics = params
                                 .diagnostics
                                 .into_iter()
-                                .map(|diagnostic| {
+                                .filter_map(|diagnostic| {
                                     use helix_core::{
                                         diagnostic::{Range, Severity, Severity::*},
                                         Diagnostic,
@@ -189,18 +189,29 @@ impl Application {
                                     let language_server = doc.language_server().unwrap();
 
                                     // TODO: convert inside server
-                                    let start = lsp_pos_to_pos(
+                                    let start = if let Some(start) = lsp_pos_to_pos(
                                         text,
                                         diagnostic.range.start,
                                         language_server.offset_encoding(),
-                                    );
-                                    let end = lsp_pos_to_pos(
+                                    ) {
+                                        start
+                                    } else {
+                                        log::warn!("lsp position out of bounds - {:?}", diagnostic);
+                                        return None;
+                                    };
+
+                                    let end = if let Some(end) = lsp_pos_to_pos(
                                         text,
                                         diagnostic.range.end,
                                         language_server.offset_encoding(),
-                                    );
+                                    ) {
+                                        end
+                                    } else {
+                                        log::warn!("lsp position out of bounds - {:?}", diagnostic);
+                                        return None;
+                                    };
 
-                                    Diagnostic {
+                                    Some(Diagnostic {
                                         range: Range { start, end },
                                         line: diagnostic.range.start.line as usize,
                                         message: diagnostic.message,
@@ -214,7 +225,7 @@ impl Application {
                                         ),
                                         // code
                                         // source
-                                    }
+                                    })
                                 })
                                 .collect();
 
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index edc3dcfd..f9db5581 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -1407,7 +1407,12 @@ fn _goto(
         let (view, doc) = editor.current();
         let definition_pos = location.range.start;
         // TODO: convert inside server
-        let new_pos = lsp_pos_to_pos(doc.text(), definition_pos, offset_encoding);
+        let new_pos =
+            if let Some(new_pos) = lsp_pos_to_pos(doc.text(), definition_pos, offset_encoding) {
+                new_pos
+            } else {
+                return;
+            };
         doc.set_selection(view.id, Selection::point(new_pos));
         align_view(doc, view, Align::Center);
     }
@@ -2297,11 +2302,7 @@ pub fn completion(cx: &mut Context) {
 
     let offset_encoding = language_server.offset_encoding();
 
-    let pos = pos_to_lsp_pos(
-        doc.text(),
-        doc.selection(view.id).cursor(),
-        language_server.offset_encoding(),
-    );
+    let pos = pos_to_lsp_pos(doc.text(), doc.selection(view.id).cursor(), offset_encoding);
 
     // TODO: handle fails
     let future = language_server.completion(doc.identifier(), pos);