Use single languages::{rust_lang, markdown_lang} in tests across the codebase (#44282)

This allows referencing proper queries and keeping the tests up-to-date.

Release Notes:

- N/A

crates/edit_prediction_context/src/edit_prediction_context_tests.rs

@@ -2,12 +2,12 @@ use super::*;
 use futures::channel::mpsc::UnboundedReceiver;
 use gpui::TestAppContext;
 use indoc::indoc;
-use language::{Language, LanguageConfig, LanguageMatcher, Point, ToPoint as _, tree_sitter_rust};
+use language::{Point, ToPoint as _, rust_lang};
 use lsp::FakeLanguageServer;
 use project::{FakeFs, LocationLink, Project};
 use serde_json::json;
 use settings::SettingsStore;
-use std::{fmt::Write as _, sync::Arc};
+use std::fmt::Write as _;
 use util::{path, test::marked_text_ranges};
 
 #[gpui::test]
@@ -508,23 +508,3 @@ fn format_excerpts(buffer: &Buffer, excerpts: &[RelatedExcerpt]) -> String {
     }
     output
 }
-
-pub(crate) fn rust_lang() -> Arc<Language> {
-    Arc::new(
-        Language::new(
-            LanguageConfig {
-                name: "Rust".into(),
-                matcher: LanguageMatcher {
-                    path_suffixes: vec!["rs".to_string()],
-                    first_line_pattern: None,
-                },
-                ..Default::default()
-            },
-            Some(tree_sitter_rust::LANGUAGE.into()),
-        )
-        .with_highlights_query(include_str!("../../languages/src/rust/highlights.scm"))
-        .unwrap()
-        .with_outline_query(include_str!("../../languages/src/rust/outline.scm"))
-        .unwrap(),
-    )
-}

crates/edit_prediction_context/src/excerpt.rs

@@ -419,30 +419,14 @@ fn node_line_end(node: Node) -> Point {
 mod tests {
     use super::*;
     use gpui::{AppContext, TestAppContext};
-    use language::{Buffer, Language, LanguageConfig, LanguageMatcher, tree_sitter_rust};
+    use language::Buffer;
     use util::test::{generate_marked_text, marked_text_offsets_by};
 
     fn create_buffer(text: &str, cx: &mut TestAppContext) -> BufferSnapshot {
-        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(rust_lang().into(), cx));
+        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(language::rust_lang(), cx));
         buffer.read_with(cx, |buffer, _| buffer.snapshot())
     }
 
-    fn rust_lang() -> Language {
-        Language::new(
-            LanguageConfig {
-                name: "Rust".into(),
-                matcher: LanguageMatcher {
-                    path_suffixes: vec!["rs".to_string()],
-                    ..Default::default()
-                },
-                ..Default::default()
-            },
-            Some(tree_sitter_rust::LANGUAGE.into()),
-        )
-        .with_outline_query(include_str!("../../languages/src/rust/outline.scm"))
-        .unwrap()
-    }
-
     fn cursor_and_excerpt_range(text: &str) -> (String, usize, Range<usize>) {
         let (text, offsets) = marked_text_offsets_by(text, vec!['ˇ', '«', '»']);
         (text, offsets[&'ˇ'][0], offsets[&'«'][0]..offsets[&'»'][0])