From cd62e60eba6b4dbb69955f128ecdaa9303c6fa3a Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Mon, 22 Aug 2022 11:43:26 +0200
Subject: [PATCH] Implement `ElixirLspAdapter::label_for_completion`

---
 crates/zed/src/languages/elixir.rs            | 54 +++++++++++++++++++
 .../zed/src/languages/elixir/highlights.scm   |  4 +-
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/crates/zed/src/languages/elixir.rs b/crates/zed/src/languages/elixir.rs
index 32abbec4c6..c6c7c8d161 100644
--- a/crates/zed/src/languages/elixir.rs
+++ b/crates/zed/src/languages/elixir.rs
@@ -4,6 +4,7 @@ use async_trait::async_trait;
 use client::http::HttpClient;
 use futures::StreamExt;
 pub use language::*;
+use lsp::CompletionItemKind;
 use smol::fs::{self, File};
 use std::{any::Any, path::PathBuf, sync::Arc};
 use util::ResultExt;
@@ -108,4 +109,57 @@ impl LspAdapter for ElixirLspAdapter {
         .await
         .log_err()
     }
+
+    async fn label_for_completion(
+        &self,
+        completion: &lsp::CompletionItem,
+        language: &Language,
+    ) -> Option<CodeLabel> {
+        match completion.kind.zip(completion.detail.as_ref()) {
+            Some((_, detail)) if detail.starts_with("(function)") => {
+                let text = detail.strip_prefix("(function) ")?;
+                let filter_range = 0..text.find('(').unwrap_or(text.len());
+                let source = Rope::from(format!("def {text}").as_str());
+                let runs = language.highlight_text(&source, 4..4 + text.len());
+                return Some(CodeLabel {
+                    text: text.to_string(),
+                    runs,
+                    filter_range,
+                });
+            }
+            Some((_, detail)) if detail.starts_with("(macro)") => {
+                let text = detail.strip_prefix("(macro) ")?;
+                let filter_range = 0..text.find('(').unwrap_or(text.len());
+                let source = Rope::from(format!("defmacro {text}").as_str());
+                let runs = language.highlight_text(&source, 9..9 + text.len());
+                return Some(CodeLabel {
+                    text: text.to_string(),
+                    runs,
+                    filter_range,
+                });
+            }
+            Some((
+                CompletionItemKind::MODULE
+                | CompletionItemKind::INTERFACE
+                | CompletionItemKind::STRUCT,
+                _,
+            )) => {
+                let filter_range = 0..completion
+                    .label
+                    .find(" (")
+                    .unwrap_or(completion.label.len());
+                let text = &completion.label[filter_range.clone()];
+                let source = Rope::from(format!("defmodule {text}").as_str());
+                let runs = language.highlight_text(&source, 10..10 + text.len());
+                return Some(CodeLabel {
+                    text: completion.label.clone(),
+                    runs,
+                    filter_range,
+                });
+            }
+            _ => {}
+        }
+
+        None
+    }
 }
diff --git a/crates/zed/src/languages/elixir/highlights.scm b/crates/zed/src/languages/elixir/highlights.scm
index 9324990391..5c256f341c 100644
--- a/crates/zed/src/languages/elixir/highlights.scm
+++ b/crates/zed/src/languages/elixir/highlights.scm
@@ -43,11 +43,11 @@
   (float)
 ] @number
 
-(alias) @module
+(alias) @type
 
 (call
   target: (dot
-    left: (atom) @module))
+    left: (atom) @type))
 
 (char) @constant