Merge #593

593: Docs for completion r=matklad a=kjeremy

The first commit adds documentation support to CompletionItems.

The second one I am unsure about. Is that the right way to add docs for functions? If so should I do something similar for other `hir` types and CompletionItems?

Co-authored-by: Jeremy Kolb <kjeremy@gmail.com>
Co-authored-by: Jeremy A. Kolb <jkolb@ara.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 88eda5ed0fd..9ae620efd4c 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use relative_path::RelativePathBuf;
 use ra_db::{CrateId, FileId};
-use ra_syntax::{ast, TreeArc, SyntaxNode};
+use ra_syntax::{ast::{self, AstNode, DocCommentsOwner}, TreeArc, SyntaxNode};
 
 use crate::{
     Name, DefId, Path, PerNs, ScopesWithSyntaxMapping, Ty, HirFileId,
@@ -352,6 +352,20 @@ impl Function {
     pub fn generic_params(&self, db: &impl HirDatabase) -> Arc<GenericParams> {
         db.generic_params(self.def_id)
     }
+
+    pub fn docs(&self, db: &impl HirDatabase) -> Option<String> {
+        let def_loc = self.def_id.loc(db);
+        let syntax = db.file_item(def_loc.source_item_id);
+        let fn_def = ast::FnDef::cast(&syntax).expect("fn def should point to FnDef node");
+
+        // doc_comment_text unconditionally returns a String
+        let comments = fn_def.doc_comment_text();
+        if comments.is_empty() {
+            None
+        } else {
+            Some(comments)
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]