diagnostics: Deduplicate diagnostics blocks

crates/diagnostics/src/diagnostic_renderer.rs

@@ -84,6 +84,7 @@ impl DiagnosticRenderer {
                     markdown: cx.new(|cx| {
                         Markdown::new(markdown.into(), language_registry.clone(), None, cx)
                     }),
+                    diagnostic_message: entry.diagnostic.message.clone(),
                 });
             } else {
                 if entry.range.start.row.abs_diff(primary.range.start.row) >= 5 {
@@ -98,6 +99,7 @@ impl DiagnosticRenderer {
                     markdown: cx.new(|cx| {
                         Markdown::new(markdown.into(), language_registry.clone(), None, cx)
                     }),
+                    diagnostic_message: entry.diagnostic.message.clone(),
                 });
             }
         }
@@ -190,9 +192,21 @@ pub(crate) struct DiagnosticBlock {
     pub(crate) initial_range: Range<Point>,
     pub(crate) severity: DiagnosticSeverity,
     pub(crate) markdown: Entity<Markdown>,
+    // Used solely for deduplicating purposes
+    pub(crate) diagnostic_message: String,
     pub(crate) diagnostics_editor: Option<Arc<dyn DiagnosticsToolbarEditor>>,
 }
 
+impl std::fmt::Debug for DiagnosticBlock {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("DiagnosticBlock")
+            .field("initial_range", &self.initial_range)
+            .field("severity", &self.severity)
+            .field("markdown", &self.markdown)
+            .finish()
+    }
+}
+
 impl DiagnosticBlock {
     pub fn render_block(&self, editor: WeakEntity<Editor>, bcx: &BlockContext) -> AnyElement {
         let cx = &bcx.app;

crates/diagnostics/src/diagnostics.rs

@@ -540,25 +540,43 @@ impl ProjectDiagnosticsEditor {
             let mut blocks: Vec<DiagnosticBlock> = Vec::new();
 
             let diagnostics_toolbar_editor = Arc::new(this.clone());
+            let languages = this
+                .read_with(cx, |t, cx| t.project.read(cx).languages().clone())
+                .ok();
+            let mut dedup_set = HashSet::default();
             for (_, group) in grouped {
                 let group_severity = group.iter().map(|d| d.diagnostic.severity).min();
                 if group_severity.is_none_or(|s| s > max_severity) {
                     continue;
                 }
-                let languages = this
-                    .read_with(cx, |t, cx| t.project.read(cx).languages().clone())
-                    .ok();
                 let more = cx.update(|_, cx| {
                     crate::diagnostic_renderer::DiagnosticRenderer::diagnostic_blocks_for_group(
                         group,
                         buffer_snapshot.remote_id(),
                         Some(diagnostics_toolbar_editor.clone()),
-                        languages,
+                        languages.clone(),
                         cx,
                     )
                 })?;
-
-                blocks.extend(more);
+                for block in more {
+                    // Remove duplicate blocks, they add no value to the user
+                    // Especially rustc tends to emit a lot of similar looking sub diagnostic spans
+                    // which can clobber the diagnostics ui
+                    //
+                    // Note we do not use the markdown output as we may modify
+                    // it to add backlinks to the diagnostics groups which will
+                    // thus always differ due to pointing to a different
+                    // diagnostic that is at the same location though
+                    //
+                    // TODO: We might steal diagnostics blocks away that are linked to givent he above
+                    if dedup_set.insert((
+                        block.initial_range,
+                        block.severity,
+                        block.diagnostic_message,
+                    )) {
+                        blocks.push(block);
+                    }
+                }
             }
 
             let cmp_excerpts = |buffer_snapshot: &BufferSnapshot,

crates/diagnostics/src/diagnostics_tests.rs

@@ -104,6 +104,30 @@ async fn test_diagnostics(cx: &mut TestAppContext) {
                     location: lsp::Location::new(uri.clone(), lsp::Range::new(lsp::Position::new(3,6),lsp::Position::new(3,7))),
                     message: "value moved here".to_string()
                 },
+                // intentional duplicate as we want to make sure that we do not render blocks with the same messages at the same locations
+                // rustc likes to do this at times
+                lsp::DiagnosticRelatedInformation {
+                    location: lsp::Location::new(uri.clone(), lsp::Range::new(lsp::Position::new(3,6),lsp::Position::new(3,7))),
+                    message: "value moved here".to_string()
+                },
+                ]),
+                ..Default::default()
+            },
+            // intentional duplicate as we want to make sure that we do not render blocks with the same messages at the same locations
+            // rustc likes to do this at times
+            lsp::Diagnostic{
+                range: lsp::Range::new(lsp::Position::new(8, 6),lsp::Position::new(8, 7)),
+                severity:Some(lsp::DiagnosticSeverity::ERROR),
+                message: "use of moved value\nvalue used here after move".to_string(),
+                related_information: Some(vec![
+                    lsp::DiagnosticRelatedInformation {
+                        location: lsp::Location::new(uri.clone(), lsp::Range::new(lsp::Position::new(1,8),lsp::Position::new(1,9))),
+                        message: "move occurs because `x` has type `Vec<char>`, which does not implement the `Copy` trait".to_string()
+                    },
+                    lsp::DiagnosticRelatedInformation {
+                        location: lsp::Location::new(uri.clone(), lsp::Range::new(lsp::Position::new(3,6),lsp::Position::new(3,7))),
+                        message: "value moved here".to_string()
+                    },
                 ]),
                 ..Default::default()
             }

crates/zeta/src/zeta.rs

@@ -423,7 +423,10 @@ impl Zeta {
         let cursor_offset = cursor_point.to_offset(&snapshot);
         let prompt_for_events = {
             let events = events.clone();
-            move || prompt_for_events_impl(&events, MAX_EVENT_TOKENS)
+            move || {
+                // let _move_me = &mut cx;
+                prompt_for_events_impl(&events, MAX_EVENT_TOKENS)
+            }
         };
         let gather_task = gather_context(
             full_path_str,