feat: reduce Debug format size for binary buffers (#13809)

* feat: reduce Image debug output

For example now:
`Image { rgba: Cow::Borrowed([u8; 4096]), width: 32, height: 32 }) }`

* feat: reduce EmbeddedAssets debug size

For example now:
```
EmbeddedAssets {
    assets: {
        "/index.html": [u8; 1835],
        "/index.js": [u8; 212],
    },
    global_hashes: [
        Script(
            "'sha256-EOd6N98xxmK5s7VvxV7W2w7YG+dmP52MqNiZUq1NLeE='",
        ),
        Style(
            "'sha256-YEercZJImS+vUX2bz7vkQ0aA4rtBIPLuCEWz+yraQ/g='",
        ),
    ],
    html_hashes: {
        "/index.html": [
            Script(
                "'sha256-3g8CfFrjFLGpwD2o+hwMt+lh/hsHbQ3XY+EPJ35fFKk='",
            ),
            Script(
                "'sha256-EOd6N98xxmK5s7VvxV7W2w7YG+dmP52MqNiZUq1NLeE='",
            ),
        ],
    },
}
```

* feat: reduce `app_icon` debug size

* chore: changelog

* chore: include tauri-utils in changelog

* doc: comment had extra closing brackets [skip ci]

.changes/reduce-debug-format-size.md

@@ -0,0 +1,6 @@
+---
+"tauri": patch:enhance
+"tauri-utils": patch:enhance
+---
+
+Reduced `Debug` format size for binary buffers.

crates/tauri-utils/src/assets.rs

@@ -113,7 +113,6 @@ impl CspHash<'_> {
 }
 
 /// [`Assets`] implementation that only contains compile-time compressed and embedded assets.
-#[derive(Debug)]
 pub struct EmbeddedAssets {
   assets: phf::Map<&'static str, &'static [u8]>,
   // Hashes that must be injected to the CSP of every HTML file.
@@ -122,6 +121,36 @@ pub struct EmbeddedAssets {
   html_hashes: phf::Map<&'static str, &'static [CspHash<'static>]>,
 }
 
+/// Temporary struct that overrides the Debug formatting for the `assets` field.
+///
+/// It reduces the output size compared to the default, as that would format the binary
+/// data as a slice of numbers like `[65, 66, 67]` for "ABC". This instead shows the length
+/// of the slice.
+///
+/// For example: `{"/index.html": [u8; 1835], "/index.js": [u8; 212]}`
+struct DebugAssetMap<'a>(&'a phf::Map<&'static str, &'static [u8]>);
+
+impl std::fmt::Debug for DebugAssetMap<'_> {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    let mut map = f.debug_map();
+    for (k, v) in self.0.entries() {
+      map.key(k);
+      map.value(&format_args!("[u8; {}]", v.len()));
+    }
+    map.finish()
+  }
+}
+
+impl std::fmt::Debug for EmbeddedAssets {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    f.debug_struct("EmbeddedAssets")
+      .field("assets", &DebugAssetMap(&self.assets))
+      .field("global_hashes", &self.global_hashes)
+      .field("html_hashes", &self.html_hashes)
+      .finish()
+  }
+}
+
 impl EmbeddedAssets {
   /// Creates a new instance from the given asset map and script hash list.
   pub const fn new(

crates/tauri/src/image/mod.rs

@@ -12,13 +12,37 @@ use std::sync::Arc;
 use crate::{Resource, ResourceId, ResourceTable};
 
 /// An RGBA Image in row-major order from top to bottom.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct Image<'a> {
   rgba: Cow<'a, [u8]>,
   width: u32,
   height: u32,
 }
 
+impl std::fmt::Debug for Image<'_> {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    f.debug_struct("Image")
+      .field(
+        "rgba",
+        // Reduces the debug size compared to the derived default, as the default
+        // would format the raw bytes as numbers `[0, 0, 0, 0]` for 1 pixel.
+        // The custom format doesn't grow as much with larger images:
+        // `Image { rgba: Cow::Borrowed([u8; 4096]), width: 32, height: 32 }`
+        &format_args!(
+          "Cow::{}([u8; {}])",
+          match &self.rgba {
+            Cow::Borrowed(_) => "Borrowed",
+            Cow::Owned(_) => "Owned",
+          },
+          self.rgba.len()
+        ),
+      )
+      .field("width", &self.width)
+      .field("height", &self.height)
+      .finish()
+  }
+}
+
 impl Resource for Image<'static> {}
 
 impl Image<'static> {

crates/tauri/src/lib.rs

@@ -397,12 +397,32 @@ pub struct Context<R: Runtime> {
   pub(crate) plugin_global_api_scripts: Option<&'static [&'static str]>,
 }
 
+/// Temporary struct that overrides the Debug formatting for the `app_icon` field.
+///
+/// It reduces the output size compared to the default, as that would format the binary
+/// data as a slice of numbers `[65, 66, 67]`. This instead shows the length of the Vec.
+///
+/// For example: `Some([u8; 493])`
+pub(crate) struct DebugAppIcon<'a>(&'a Option<Vec<u8>>);
+
+impl std::fmt::Debug for DebugAppIcon<'_> {
+  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+    match self.0 {
+      Option::None => f.write_str("None"),
+      Option::Some(icon) => f
+        .debug_tuple("Some")
+        .field(&format_args!("[u8; {}]", icon.len()))
+        .finish(),
+    }
+  }
+}
+
 impl<R: Runtime> fmt::Debug for Context<R> {
   fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
     let mut d = f.debug_struct("Context");
     d.field("config", &self.config)
       .field("default_window_icon", &self.default_window_icon)
-      .field("app_icon", &self.app_icon)
+      .field("app_icon", &DebugAppIcon(&self.app_icon))
       .field("package_info", &self.package_info)
       .field("pattern", &self.pattern)
       .field("plugin_global_api_scripts", &self.plugin_global_api_scripts);

crates/tauri/src/manager/mod.rs

@@ -18,7 +18,6 @@ use tauri_utils::{
   config::{Csp, CspDirectiveSources},
 };
 
-use crate::resources::ResourceTable;
 use crate::{
   app::{
     AppHandle, ChannelInterceptor, GlobalWebviewEventListener, GlobalWindowEventListener,
@@ -27,8 +26,9 @@ use crate::{
   event::{EmitArgs, Event, EventId, EventTarget, Listeners},
   ipc::{Invoke, InvokeHandler, RuntimeAuthority},
   plugin::PluginStore,
+  resources::ResourceTable,
   utils::{config::Config, PackageInfo},
-  Assets, Context, EventName, Pattern, Runtime, StateManager, Webview, Window,
+  Assets, Context, DebugAppIcon, EventName, Pattern, Runtime, StateManager, Webview, Window,
 };
 
 #[cfg(desktop)]
@@ -233,7 +233,7 @@ impl<R: Runtime> fmt::Debug for AppManager<R> {
       .field("plugins", &self.plugins)
       .field("state", &self.state)
       .field("config", &self.config)
-      .field("app_icon", &self.app_icon)
+      .field("app_icon", &DebugAppIcon(&self.app_icon))
       .field("package_info", &self.package_info)
       .field("pattern", &self.pattern);