Merge #6140

6140: honour hover.content_format client capability r=lnicola a=robinvd

This removes all markdown when the client does not support the markdown MarkupKind.

Otherwise the output on the editor will have some markdown boilerplate, making it less readable.

For example kak_lsp does not currently support markdown.
![image](https://user-images.githubusercontent.com/22073483/95112949-ef0ff080-0741-11eb-82a7-0594fa2cd736.png)

after:
![image](https://user-images.githubusercontent.com/22073483/95113089-2bdbe780-0742-11eb-94fa-bcfec6d7347a.png)



Co-authored-by: Robin van Dijk <robin@robinjint.nl>

crates/ide/src/hover.rs

@@ -15,6 +15,7 @@ use test_utils::mark;
 use crate::{
     display::{macro_label, ShortLabel, ToNav, TryToNav},
     link_rewrite::{remove_links, rewrite_links},
+    markdown_remove::remove_markdown,
     markup::Markup,
     runnables::runnable,
     FileId, FilePosition, NavigationTarget, RangeInfo, Runnable,
@@ -27,6 +28,7 @@ pub struct HoverConfig {
     pub debug: bool,
     pub goto_type_def: bool,
     pub links_in_hover: bool,
+    pub markdown: bool,
 }
 
 impl Default for HoverConfig {
@@ -37,6 +39,7 @@ impl Default for HoverConfig {
             debug: true,
             goto_type_def: true,
             links_in_hover: true,
+            markdown: true,
         }
     }
 }
@@ -48,6 +51,7 @@ impl HoverConfig {
         debug: false,
         goto_type_def: false,
         links_in_hover: true,
+        markdown: true,
     };
 
     pub fn any(&self) -> bool {
@@ -91,6 +95,7 @@ pub(crate) fn hover(
     db: &RootDatabase,
     position: FilePosition,
     links_in_hover: bool,
+    markdown: bool,
 ) -> Option<RangeInfo<HoverResult>> {
     let sema = Semantics::new(db);
     let file = sema.parse(position.file_id).syntax().clone();
@@ -109,7 +114,9 @@ pub(crate) fn hover(
     };
     if let Some(definition) = definition {
         if let Some(markup) = hover_for_definition(db, definition) {
-            let markup = if links_in_hover {
+            let markup = if !markdown {
+                remove_markdown(&markup.as_str())
+            } else if links_in_hover {
                 rewrite_links(db, &markup.as_str(), &definition)
             } else {
                 remove_links(&markup.as_str())
@@ -147,7 +154,11 @@ pub(crate) fn hover(
         }
     };
 
-    res.markup = Markup::fenced_block(&ty.display(db));
+    res.markup = if markdown {
+        Markup::fenced_block(&ty.display(db))
+    } else {
+        ty.display(db).to_string().into()
+    };
     let range = sema.original_range(&node).range;
     Some(RangeInfo::new(range, res))
 }
@@ -383,12 +394,12 @@ mod tests {
 
     fn check_hover_no_result(ra_fixture: &str) {
         let (analysis, position) = fixture::position(ra_fixture);
-        assert!(analysis.hover(position, true).unwrap().is_none());
+        assert!(analysis.hover(position, true, true).unwrap().is_none());
     }
 
     fn check(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, true).unwrap().unwrap();
+        let hover = analysis.hover(position, true, true).unwrap().unwrap();
 
         let content = analysis.db.file_text(position.file_id);
         let hovered_element = &content[hover.range];
@@ -399,7 +410,18 @@ mod tests {
 
     fn check_hover_no_links(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, false).unwrap().unwrap();
+        let hover = analysis.hover(position, false, true).unwrap().unwrap();
+
+        let content = analysis.db.file_text(position.file_id);
+        let hovered_element = &content[hover.range];
+
+        let actual = format!("*{}*\n{}\n", hovered_element, hover.info.markup);
+        expect.assert_eq(&actual)
+    }
+
+    fn check_hover_no_markdown(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let hover = analysis.hover(position, true, false).unwrap().unwrap();
 
         let content = analysis.db.file_text(position.file_id);
         let hovered_element = &content[hover.range];
@@ -410,7 +432,7 @@ mod tests {
 
     fn check_actions(ra_fixture: &str, expect: Expect) {
         let (analysis, position) = fixture::position(ra_fixture);
-        let hover = analysis.hover(position, true).unwrap().unwrap();
+        let hover = analysis.hover(position, true, true).unwrap().unwrap();
         expect.assert_debug_eq(&hover.info.actions)
     }
 
@@ -433,6 +455,23 @@ fn main() {
         );
     }
 
+    #[test]
+    fn hover_remove_markdown_if_configured() {
+        check_hover_no_markdown(
+            r#"
+pub fn foo() -> u32 { 1 }
+
+fn main() {
+    let foo_test = foo()<|>;
+}
+"#,
+            expect![[r#"
+                *foo()*
+                u32
+            "#]],
+        );
+    }
+
     #[test]
     fn hover_shows_long_type_of_an_expression() {
         check(

crates/ide/src/lib.rs

@@ -46,6 +46,7 @@ mod syntax_highlighting;
 mod syntax_tree;
 mod typing;
 mod link_rewrite;
+mod markdown_remove;
 
 use std::sync::Arc;
 
@@ -376,8 +377,9 @@ impl Analysis {
         &self,
         position: FilePosition,
         links_in_hover: bool,
+        markdown: bool,
     ) -> Cancelable<Option<RangeInfo<HoverResult>>> {
-        self.with_db(|db| hover::hover(db, position, links_in_hover))
+        self.with_db(|db| hover::hover(db, position, links_in_hover, markdown))
     }
 
     /// Computes parameter information for the given call expression.

crates/ide/src/markdown_remove.rs

@@ -0,0 +1,23 @@
+//! Removes markdown from strings.
+
+use pulldown_cmark::{Event, Parser, Tag};
+
+/// Removes all markdown, keeping the text and code blocks
+///
+/// Currently limited in styling, i.e. no ascii tables or lists
+pub fn remove_markdown(markdown: &str) -> String {
+    let mut out = String::new();
+    let parser = Parser::new(markdown);
+
+    for event in parser {
+        match event {
+            Event::Text(text) | Event::Code(text) => out.push_str(&text),
+            Event::SoftBreak | Event::HardBreak | Event::Rule | Event::End(Tag::CodeBlock(_)) => {
+                out.push('\n')
+            }
+            _ => {}
+        }
+    }
+
+    out
+}

crates/rust-analyzer/src/config.rs

@@ -15,7 +15,7 @@ use ide::{
     AssistConfig, CompletionConfig, DiagnosticsConfig, HoverConfig, InlayHintsConfig,
     MergeBehaviour,
 };
-use lsp_types::ClientCapabilities;
+use lsp_types::{ClientCapabilities, MarkupKind};
 use project_model::{CargoConfig, ProjectJson, ProjectJsonData, ProjectManifest};
 use rustc_hash::FxHashSet;
 use serde::Deserialize;
@@ -333,6 +333,7 @@ impl Config {
             debug: data.hoverActions_enable && data.hoverActions_debug,
             goto_type_def: data.hoverActions_enable && data.hoverActions_gotoTypeDef,
             links_in_hover: data.hoverActions_linksInHover,
+            markdown: true,
         };
 
         log::info!("Config::update() = {:#?}", self);
@@ -340,6 +341,9 @@ impl Config {
 
     pub fn update_caps(&mut self, caps: &ClientCapabilities) {
         if let Some(doc_caps) = caps.text_document.as_ref() {
+            if let Some(value) = doc_caps.hover.as_ref().and_then(|it| it.content_format.as_ref()) {
+                self.hover.markdown = value.contains(&MarkupKind::Markdown)
+            }
             if let Some(value) = doc_caps.definition.as_ref().and_then(|it| it.link_support) {
                 self.client_caps.location_link = value;
             }

crates/rust-analyzer/src/handlers.rs

@@ -618,7 +618,11 @@ pub(crate) fn handle_hover(
 ) -> Result<Option<lsp_ext::Hover>> {
     let _p = profile::span("handle_hover");
     let position = from_proto::file_position(&snap, params.text_document_position_params)?;
-    let info = match snap.analysis.hover(position, snap.config.hover.links_in_hover)? {
+    let info = match snap.analysis.hover(
+        position,
+        snap.config.hover.links_in_hover,
+        snap.config.hover.markdown,
+    )? {
         None => return Ok(None),
         Some(info) => info,
     };