Fix CI: rustfmt and keep GUI deps off the Linux lib job

Make xcap/winit/pixels/image optional under the default `gui` feature so
`cargo clippy/test --lib --no-default-features` no longer needs dbus on
Ubuntu. Format main.rs for rustfmt.

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Check formatting
         run: cargo fmt --all -- --check
 
-  # Pure logic only — no windowing / screenshot deps, runs on Linux.
+  # Pure logic only — no GUI / capture deps (feature "gui" off).
   lib:
     name: clippy + test (lib)
     runs-on: ubuntu-latest
@@ -31,9 +31,7 @@ jobs:
         with:
           components: clippy
       - uses: Swatinem/rust-cache@v2
-      # --lib only: pure logic, no GUI binary. (Do not use --all-targets / --tests
-      # here — those also compile the macOS-only binary target.)
-      - name: Clippy (lib)
-        run: cargo clippy --lib -- -D warnings
-      - name: Tests (lib)
-        run: cargo test --lib
+      - name: Clippy (lib, no gui)
+        run: cargo clippy --lib --no-default-features -- -D warnings
+      - name: Tests (lib, no gui)
+        run: cargo test --lib --no-default-features

Cargo.toml

@@ -10,13 +10,19 @@ path = "src/lib.rs"
 [[bin]]
 name = "moomer"
 path = "src/main.rs"
+required-features = ["gui"]
+
+[features]
+default = ["gui"]
+# GUI / capture stack — only needed for the binary. Lib CI uses --no-default-features.
+gui = ["dep:xcap", "dep:winit", "dep:pixels", "dep:image"]
 
 [dependencies]
-# screenshots is unmaintained (future-incompat) and points users at xcap.
-xcap = "0.4"
-winit = "0.28"
-pixels = "0.13"
-image = "0.25"
+# screenshots is unmaintained (future-incompat); xcap is the maintained replacement.
+xcap = { version = "0.4", optional = true }
+winit = { version = "0.28", optional = true }
+pixels = { version = "0.13", optional = true }
+image = { version = "0.25", optional = true }
 
 [target.'cfg(target_os = "macos")'.dependencies]
 cocoa = "0.25"
@@ -27,4 +33,3 @@ libc = "0.2"
 # Declare it so rustc's unexpected_cfgs lint stays quiet.
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = ['cfg(feature, values("cargo-clippy"))'] }
-

README.md

@@ -48,11 +48,12 @@ GitHub Actions (Linux) runs:
 
 ```bash
 $ cargo fmt --all -- --check
-$ cargo clippy --lib -- -D warnings
-$ cargo test --lib
+$ cargo clippy --lib --no-default-features -- -D warnings
+$ cargo test --lib --no-default-features
 ```
 
-Platform-independent logic lives in `src/lib.rs` so those jobs do not need macOS or a display.
+Platform-independent logic lives in `src/lib.rs`. The `gui` feature (default on) pulls in
+`xcap` / `winit` / `pixels` for the binary; CI disables it so Linux runners never need dbus/X11.
 
 ## Running
 

src/main.rs

@@ -3,7 +3,6 @@ use moomer::best_capture_for_monitor;
 use moomer::{apply_zoom, physical_dims, ViewState};
 use pixels::{Pixels, SurfaceTexture};
 use std::collections::HashMap;
-use xcap::Monitor;
 use std::fs::OpenOptions;
 use std::io::Write;
 use std::sync::Mutex;
@@ -16,6 +15,7 @@ use winit::{
     event_loop::{ControlFlow, EventLoop},
     window::{Window, WindowBuilder, WindowId},
 };
+use xcap::Monitor;
 
 /// Dual log: stderr + /tmp/moomer.log (so hotkey / Raycast launches still leave a trail).
 static LOG_FILE: Mutex<Option<std::fs::File>> = Mutex::new(None);
@@ -910,9 +910,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let target_monitor = {
         #[cfg(target_os = "macos")]
         {
-            let by_id = macos::display_id_under_cursor().and_then(|id| {
-                monitors.iter().find(|m| m.id().ok() == Some(id)).cloned()
-            });
+            let by_id = macos::display_id_under_cursor()
+                .and_then(|id| monitors.iter().find(|m| m.id().ok() == Some(id)).cloned());
             if let Some(m) = by_id {
                 log(format!(
                     "main: target display under cursor = id={} primary={} {}x{} @ ({},{})",