feat(editor): highlight Arduino sketches as C++ (#1874)

Open .ino sketches with C++ highlighting and the C++ file icon. Sketches get their own Arduino language with no language server: clangd can't compile a sketch on its own (implicit Arduino.h, generated prototypes) and reported "Unable to handle compilation" on line 1 of every sketch.

Co-authored-by: mushketer888 <[email protected]>

crates/ide-language/src/registry.rs

@@ -9,6 +9,7 @@ use std::sync::{Arc, OnceLock};
 
 /// Built-in definitions, embedded at compile time. Add new languages here.
 const BUILTIN: &[(&str, &str)] = &[
+    ("arduino", include_str!("../../../languages/arduino.toml")),
     ("asciidoc", include_str!("../../../languages/asciidoc.toml")),
     ("astro", include_str!("../../../languages/astro.toml")),
     ("bat", include_str!("../../../languages/bat.toml")),
@@ -860,6 +861,7 @@ mod tests {
             ("x.h", "c"),
             ("x.hpp", "cpp"),
             ("x.cc", "cpp"),
+            ("blink.ino", "arduino"),
             ("P.cs", "csharp"),
             ("V.swift", "swift"),
             ("AppDelegate.m", "objective-c"),

languages/arduino.toml

@@ -0,0 +1,10 @@
+id = "arduino"
+name = "Arduino"
+# Sketches are C++ with an implicit `Arduino.h` and generated prototypes; clangd can't compile
+# them on its own, so they get C++ highlighting without a language server.
+extensions = ["ino"]
+line-comment = "//"
+block-comment = ["/*", "*/"]
+indent = { tab-size = 2, insert-spaces = true }
+ui-mode = "C++"
+tree-sitter = "cpp"

src/ui/icons.tsx

@@ -991,7 +991,7 @@ const EXT_ICONS = table({
   "file-perl": "pl pm pod psgi cgi",
   "file-c": "c",
   "file-h": "h hpp hh hxx h++",
-  "file-cpp": "cpp cc cxx c++ ipp tpp inl ixx cppm",
+  "file-cpp": "cpp cc cxx c++ ipp tpp inl ixx cppm ino",
   "file-objc": "m",
   "file-objcpp": "mm",
   "file-csharp": "cs csx",