feat(core): allow config app dir override

.changes/app-directories-override.md

@@ -0,0 +1,5 @@
+---
+"tauri": minor:feat
+---
+
+Introduce a new config `appDirectoriesOverride` that changes what `app_*_dir` APIs return, useful for putting all your data besides the executable for testing or as portable apps

crates/tauri-cli/config.schema.json

@@ -217,6 +217,13 @@
           "description": "If set to true \"identifier\" will be set as GTK app ID (on systems that use GTK).",
           "default": false,
           "type": "boolean"
+        },
+        "appDirectoriesOverride": {
+          "description": "Override the path returned from `app_*_dir` APIs,\n this is useful for making portable apps that stores all the data inside a single place\n\n Note:\n   - Relative paths are resolved based on the app's executable path,\n   - The path can start with a variable that resolves to a system base directory.\n     The variables are: `$AUDIO`, `$CACHE`, `$CONFIG`, `$DATA`, `$LOCALDATA`, `$DOCUMENT`, `$DOWNLOAD`, `$PICTURE`,\n     `$PUBLIC`, `$VIDEO`, `$RESOURCE`, `$TEMP`, `$HOME`, `$DESKTOP`, `$EXE`, `$FONT`, `$RUNTIME`, `$TEMPLATE`\n\n ## Example:\n\n To put all the data besides your current executable:\n\n ```json\n {\n   \"app\": {\n     \"appDirectoriesOverride\": \"./\"\n   }\n }\n ```\n\n `app.path().app_local_data_dir()` should now return `${current_exe_dir}/`\n\n ## Platform-specific:\n\n - **Android**: Unsupported.",
+          "type": [
+            "string",
+            "null"
+          ]
         }
       },
       "additionalProperties": false

crates/tauri-schema-generator/schemas/config.schema.json

@@ -217,6 +217,13 @@
           "description": "If set to true \"identifier\" will be set as GTK app ID (on systems that use GTK).",
           "default": false,
           "type": "boolean"
+        },
+        "appDirectoriesOverride": {
+          "description": "Override the path returned from `app_*_dir` APIs,\n this is useful for making portable apps that stores all the data inside a single place\n\n Note:\n   - Relative paths are resolved based on the app's executable path,\n   - The path can start with a variable that resolves to a system base directory.\n     The variables are: `$AUDIO`, `$CACHE`, `$CONFIG`, `$DATA`, `$LOCALDATA`, `$DOCUMENT`, `$DOWNLOAD`, `$PICTURE`,\n     `$PUBLIC`, `$VIDEO`, `$RESOURCE`, `$TEMP`, `$HOME`, `$DESKTOP`, `$EXE`, `$FONT`, `$RUNTIME`, `$TEMPLATE`\n\n ## Example:\n\n To put all the data besides your current executable:\n\n ```json\n {\n   \"app\": {\n     \"appDirectoriesOverride\": \"./\"\n   }\n }\n ```\n\n `app.path().app_local_data_dir()` should now return `${current_exe_dir}/`\n\n ## Platform-specific:\n\n - **Android**: Unsupported.",
+          "type": [
+            "string",
+            "null"
+          ]
         }
       },
       "additionalProperties": false

crates/tauri-utils/src/config.rs

@@ -2763,6 +2763,34 @@ pub struct AppConfig {
   /// If set to true "identifier" will be set as GTK app ID (on systems that use GTK).
   #[serde(rename = "enableGTKAppId", alias = "enable-gtk-app-id", default)]
   pub enable_gtk_app_id: bool,
+  /// Override the path returned from `app_*_dir` APIs,
+  /// this is useful for making portable apps that stores all the data inside a single place
+  ///
+  /// Note:
+  ///   - Relative paths are resolved based on the app's executable path,
+  ///   - The path can start with a variable that resolves to a system base directory.
+  ///     The variables are: `$AUDIO`, `$CACHE`, `$CONFIG`, `$DATA`, `$LOCALDATA`, `$DOCUMENT`, `$DOWNLOAD`, `$PICTURE`,
+  ///     `$PUBLIC`, `$VIDEO`, `$RESOURCE`, `$TEMP`, `$HOME`, `$DESKTOP`, `$EXE`, `$FONT`, `$RUNTIME`, `$TEMPLATE`
+  ///
+  /// ## Example:
+  ///
+  /// To put all the data besides your current executable:
+  ///
+  /// ```json
+  /// {
+  ///   "app": {
+  ///     "appDirectoriesOverride": "./"
+  ///   }
+  /// }
+  /// ```
+  ///
+  /// `app.path().app_local_data_dir()` should now return `${current_exe_dir}/`
+  ///
+  /// ## Platform-specific:
+  ///
+  /// - **Android**: Unsupported.
+  #[serde(alias = "app-directories-override")]
+  pub app_directories_override: Option<PathBuf>,
 }
 
 impl AppConfig {
@@ -4029,6 +4057,13 @@ mod build {
       let macos_private_api = self.macos_private_api;
       let with_global_tauri = self.with_global_tauri;
       let enable_gtk_app_id = self.enable_gtk_app_id;
+      let app_directories_override = opt_lit(
+        self
+          .app_directories_override
+          .as_ref()
+          .map(path_buf_lit)
+          .as_ref(),
+      );
 
       literal_struct!(
         tokens,
@@ -4038,7 +4073,8 @@ mod build {
         tray_icon,
         macos_private_api,
         with_global_tauri,
-        enable_gtk_app_id
+        enable_gtk_app_id,
+        app_directories_override
       );
     }
   }
@@ -4119,6 +4155,7 @@ mod test {
       macos_private_api: false,
       with_global_tauri: false,
       enable_gtk_app_id: false,
+      app_directories_override: None,
     };
 
     // create a build config

crates/tauri/src/manager/webview.rs

@@ -506,11 +506,7 @@ impl<R: Runtime> WebviewManager<R> {
     // but we do respect user-specification
     #[cfg(any(target_os = "linux", target_os = "windows"))]
     if pending.webview_attributes.data_directory.is_none() {
-      let local_app_data = manager.path().resolve(
-        &app_manager.config.identifier,
-        crate::path::BaseDirectory::LocalData,
-      );
-      if let Ok(user_data_dir) = local_app_data {
+      if let Ok(user_data_dir) = manager.path().app_local_data_dir() {
         pending.webview_attributes.data_directory = Some(user_data_dir);
       }
     }

crates/tauri/src/path/desktop.rs

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 
 use super::{Error, Result};
-use crate::{AppHandle, Manager, Runtime};
+use crate::{path::BaseDirectory, AppHandle, Manager, Runtime};
 use std::path::{Path, PathBuf};
 
 /// The path resolver is a helper class for general and application-specific path APIs.
@@ -236,6 +236,10 @@ impl<R: Runtime> PathResolver<R> {
   ///
   /// Resolves to [`config_dir`](Self::config_dir)`/${bundle_identifier}`.
   pub fn app_config_dir(&self) -> Result<PathBuf> {
+    if let Some(app_directories_override) = self.resolve_app_directories_override() {
+      return app_directories_override;
+    }
+
     dirs::config_dir()
       .ok_or(Error::UnknownPath)
       .map(|dir| dir.join(&self.0.config().identifier))
@@ -245,6 +249,10 @@ impl<R: Runtime> PathResolver<R> {
   ///
   /// Resolves to [`data_dir`](Self::data_dir)`/${bundle_identifier}`.
   pub fn app_data_dir(&self) -> Result<PathBuf> {
+    if let Some(app_directories_override) = self.resolve_app_directories_override() {
+      return app_directories_override;
+    }
+
     dirs::data_dir()
       .ok_or(Error::UnknownPath)
       .map(|dir| dir.join(&self.0.config().identifier))
@@ -254,6 +262,10 @@ impl<R: Runtime> PathResolver<R> {
   ///
   /// Resolves to [`local_data_dir`](Self::local_data_dir)`/${bundle_identifier}`.
   pub fn app_local_data_dir(&self) -> Result<PathBuf> {
+    if let Some(app_directories_override) = self.resolve_app_directories_override() {
+      return app_directories_override;
+    }
+
     dirs::data_local_dir()
       .ok_or(Error::UnknownPath)
       .map(|dir| dir.join(&self.0.config().identifier))
@@ -263,6 +275,10 @@ impl<R: Runtime> PathResolver<R> {
   ///
   /// Resolves to [`cache_dir`](Self::cache_dir)`/${bundle_identifier}`.
   pub fn app_cache_dir(&self) -> Result<PathBuf> {
+    if let Some(app_directories_override) = self.resolve_app_directories_override() {
+      return Ok(app_directories_override?.join("caches"));
+    }
+
     dirs::cache_dir()
       .ok_or(Error::UnknownPath)
       .map(|dir| dir.join(&self.0.config().identifier))
@@ -276,6 +292,10 @@ impl<R: Runtime> PathResolver<R> {
   /// - **macOS:** Resolves to [`home_dir`](Self::home_dir)`/Library/Logs/${bundle_identifier}`
   /// - **Windows:** Resolves to [`local_data_dir`](Self::local_data_dir)`/${bundle_identifier}/logs`.
   pub fn app_log_dir(&self) -> Result<PathBuf> {
+    if let Some(app_directories_override) = self.resolve_app_directories_override() {
+      return Ok(app_directories_override?.join("logs"));
+    }
+
     #[cfg(target_os = "macos")]
     let path = dirs::home_dir()
       .ok_or(Error::UnknownPath)
@@ -293,4 +313,39 @@ impl<R: Runtime> PathResolver<R> {
   pub fn temp_dir(&self) -> Result<PathBuf> {
     Ok(std::env::temp_dir())
   }
+
+  /// Resolves the `app_directories_override` based on `current_exe` if it exists
+  fn resolve_app_directories_override(&self) -> Option<Result<PathBuf>> {
+    let app_directories_override = self.0.config().app.app_directories_override.as_ref();
+    app_directories_override.map(|app_directories_override| {
+      if let Some(base_directory) = app_directories_override
+        .components()
+        .next()
+        .and_then(|str| BaseDirectory::from_variable(str.as_os_str().to_str()?))
+      {
+        return if matches!(
+          base_directory,
+          BaseDirectory::AppCache
+            | BaseDirectory::AppConfig
+            | BaseDirectory::AppData
+            | BaseDirectory::AppLocalData
+            | BaseDirectory::AppLog
+        ) {
+          // TODO: Maybe add a new variant?
+          Err(crate::Error::UnknownPath)
+        } else {
+          self.parse(app_directories_override)
+        };
+      }
+
+      Ok(if app_directories_override.is_absolute() {
+        app_directories_override.clone()
+      } else {
+        crate::process::current_binary(&self.0.env())?
+          .parent()
+          .ok_or(crate::Error::NoParent)?
+          .join(app_directories_override)
+      })
+    })
+  }
 }

crates/tauri/src/test/mod.rs

@@ -121,6 +121,7 @@ pub fn mock_context<R: Runtime, A: Assets<R>>(assets: A) -> crate::Context<R> {
         tray_icon: None,
         macos_private_api: false,
         enable_gtk_app_id: false,
+        app_directories_override: None,
       },
       bundle: Default::default(),
       build: Default::default(),