feat: support supplementary environment variables for hooks in App

apps/app-frontend/src/components/ui/instance_settings/HooksSettings.vue

@@ -56,6 +56,35 @@ const messages = defineMessages({
 		defaultMessage:
 			'Hooks allow advanced users to run certain system commands before and after launching the game.',
 	},
+	hookVariablesDescription: {
+		id: 'instance.settings.tabs.hooks.variables.description',
+		defaultMessage:
+			'Hooks run in the working directory of the instance, with the following variables:',
+	},
+	instanceNameDescription: {
+		id: 'instance.settings.tabs.hooks.variables.inst-name.description',
+		defaultMessage: '$INST_NAME: The name of the instance',
+	},
+	instanceIdDescription: {
+		id: 'instance.settings.tabs.hooks.variables.inst-id.description',
+		defaultMessage: "$INST_ID: The name of the instance's folder",
+	},
+	instanceDirDescription: {
+		id: 'instance.settings.tabs.hooks.variables.inst-dir.description',
+		defaultMessage: "$INST_DIR: The absolute path to the instance's folder",
+	},
+	instanceMcDirDescription: {
+		id: 'instance.settings.tabs.hooks.variables.inst-mc-dir.description',
+		defaultMessage: '$INST_MC_DIR: An alias for $INST_DIR',
+	},
+	instanceJavaDescription: {
+		id: 'instance.settings.tabs.hooks.variables.inst-java.description',
+		defaultMessage: '$INST_JAVA: The absolute path to the java binary',
+	},
+	instanceJavaArgsDescription: {
+		id: 'instance.settings.tabs.hooks.variables.inst-java-args.description',
+		defaultMessage: '$INST_JAVA_ARGS: The JVM Arguments provided to the game',
+	},
 	customHooks: {
 		id: 'instance.settings.tabs.hooks.custom-hooks',
 		defaultMessage: 'Custom launch hooks',
@@ -153,5 +182,17 @@ const messages = defineMessages({
 		<p class="m-0">
 			{{ formatMessage(messages.postExitDescription) }}
 		</p>
+
+		<div class="m-0 mt-6">
+			{{ formatMessage(messages.hookVariablesDescription) }}
+		</div>
+		<ul class="m-0 mt-2">
+			<li>{{ formatMessage(messages.instanceNameDescription) }}</li>
+			<li>{{ formatMessage(messages.instanceIdDescription) }}</li>
+			<li>{{ formatMessage(messages.instanceDirDescription) }}</li>
+			<li>{{ formatMessage(messages.instanceMcDirDescription) }}</li>
+			<li>{{ formatMessage(messages.instanceJavaDescription) }}</li>
+			<li>{{ formatMessage(messages.instanceJavaArgsDescription) }}</li>
+		</ul>
 	</div>
 </template>

apps/app-frontend/src/components/ui/settings/DefaultInstanceSettings.vue

@@ -181,6 +181,18 @@ watch(
 				/>
 				<p class="m-0 leading-tight">Ran after the game closes.</p>
 			</div>
+
+			<div class="m-0 leading-tight">
+				Hooks run in the working directory of the instance, with the following variables:
+				<ul>
+					<li>$INST_NAME: The name of the instance</li>
+					<li>$INST_ID: The name of the instance's folder</li>
+					<li>$INST_DIR: The absolute path to the instance's folder</li>
+					<li>$INST_MC_DIR: An alias for $INST_DIR</li>
+					<li>$INST_JAVA: The absolute path to the java binary</li>
+					<li>$INST_JAVA_ARGS: The JVM Arguments provided to the game</li>
+				</ul>
+			</div>
 		</div>
 	</div>
 </template>

apps/app-frontend/src/locales/en-US/index.json

@@ -593,6 +593,27 @@
   "instance.settings.tabs.hooks.title": {
     "message": "Game launch hooks"
   },
+  "instance.settings.tabs.hooks.variables.description": {
+    "message": "Hooks run in the working directory of the instance, with the following variables:"
+  },
+  "instance.settings.tabs.hooks.variables.inst-dir.description": {
+    "message": "$INST_DIR: The absolute path to the instance's folder"
+  },
+  "instance.settings.tabs.hooks.variables.inst-id.description": {
+    "message": "$INST_ID: The name of the instance's folder"
+  },
+  "instance.settings.tabs.hooks.variables.inst-java-args.description": {
+    "message": "$INST_JAVA_ARGS: The JVM Arguments provided to the game"
+  },
+  "instance.settings.tabs.hooks.variables.inst-java.description": {
+    "message": "$INST_JAVA: The absolute path to the java binary"
+  },
+  "instance.settings.tabs.hooks.variables.inst-mc-dir.description": {
+    "message": "$INST_MC_DIR: An alias for $INST_DIR"
+  },
+  "instance.settings.tabs.hooks.variables.inst-name.description": {
+    "message": "$INST_NAME: The name of the instance"
+  },
   "instance.settings.tabs.hooks.wrapper": {
     "message": "Wrapper"
   },

packages/app-lib/src/api/profile/mod.rs

@@ -785,15 +785,84 @@ async fn run_credentials(
         ))
     })?;
 
-    let pre_launch_hooks = profile
+    let pre_launch_hook = profile
         .hooks
         .pre_launch
         .as_ref()
         .or(settings.hooks.pre_launch.as_ref())
         .filter(|hook_command| !hook_command.is_empty());
-    if let Some(hook) = pre_launch_hooks {
-        // TODO: hook parameters
-        let mut cmd = shlex::split(hook)
+
+    let java_args = profile
+        .extra_launch_args
+        .clone()
+        .unwrap_or(settings.extra_launch_args);
+
+    let wrapper = profile
+        .hooks
+        .wrapper
+        .clone()
+        .or(settings.hooks.wrapper)
+        .filter(|hook_command| !hook_command.is_empty());
+
+    let env_args = profile
+        .custom_env_vars
+        .clone()
+        .unwrap_or(settings.custom_env_vars);
+
+    // Post post exit hooks
+    let post_exit_hook = profile
+        .hooks
+        .post_exit
+        .clone()
+        .or(settings.hooks.post_exit)
+        .filter(|hook_command| !hook_command.is_empty());
+
+    let memory = profile.memory.unwrap_or(settings.memory);
+    let resolution =
+        profile.game_resolution.unwrap_or(settings.game_resolution);
+    let has_hook_commands = pre_launch_hook.is_some()
+        || wrapper.is_some()
+        || post_exit_hook.is_some();
+    let full_path = if has_hook_commands {
+        Some(get_full_path(&profile.path).await?)
+    } else {
+        None
+    };
+    let hook_environment = if has_hook_commands {
+        let full_path = full_path
+            .as_ref()
+            .expect("hooked launches always resolve their instance path");
+        let java_version =
+            crate::launcher::resolve_java_for_launch(&profile).await?;
+
+        Some(crate::launcher::hooks::HookEnvironment::from_current_env(
+            &env_args,
+            crate::launcher::hooks::HookVariables {
+                instance_name: profile.name.clone(),
+                instance_id: profile.path.clone(),
+                instance_dir: full_path.to_string_lossy().to_string(),
+                java_path: java_version.path.clone(),
+                java_args: crate::launcher::hooks::build_hook_java_args(
+                    &java_args,
+                    memory,
+                    &java_version,
+                ),
+            },
+        ))
+    } else {
+        None
+    };
+    let launch_env_args = hook_environment
+        .as_ref()
+        .map_or_else(|| env_args.clone(), |env| env.injected_envs());
+
+    if let (Some(hook), Some(hook_environment), Some(full_path)) = (
+        pre_launch_hook,
+        hook_environment.as_ref(),
+        full_path.as_ref(),
+    ) {
+        let expanded_hook = hook_environment.expand(hook);
+        let mut cmd = shlex::split(&expanded_hook)
             .ok_or_else(|| {
                 crate::ErrorKind::LauncherError(format!(
                     "Invalid pre-launch command: {hook}",
@@ -802,12 +871,12 @@ async fn run_credentials(
             .into_iter();
 
         if let Some(command) = cmd.next() {
-            let full_path = get_full_path(&profile.path).await?;
             let result = Command::new(command)
                 .args(cmd)
-                .current_dir(&full_path)
+                .envs(launch_env_args.iter().cloned())
+                .current_dir(full_path)
                 .spawn()
-                .map_err(|e| IOError::with_path(e, &full_path))?
+                .map_err(|e| IOError::with_path(e, full_path))?
                 .wait()
                 .await
                 .map_err(IOError::from)?;
@@ -822,33 +891,19 @@ async fn run_credentials(
         }
     }
 
-    let java_args = profile
-        .extra_launch_args
-        .clone()
-        .unwrap_or(settings.extra_launch_args);
-
-    let wrapper = profile
-        .hooks
-        .wrapper
-        .clone()
-        .or(settings.hooks.wrapper)
+    let wrapper = wrapper
+        .map(|hook| {
+            hook_environment
+                .as_ref()
+                .map_or(hook.clone(), |env| env.expand(&hook))
+        })
         .filter(|hook_command| !hook_command.is_empty());
-
-    let memory = profile.memory.unwrap_or(settings.memory);
-    let resolution =
-        profile.game_resolution.unwrap_or(settings.game_resolution);
-
-    let env_args = profile
-        .custom_env_vars
-        .clone()
-        .unwrap_or(settings.custom_env_vars);
-
-    // Post post exit hooks
-    let post_exit_hook = profile
-        .hooks
-        .post_exit
-        .clone()
-        .or(settings.hooks.post_exit)
+    let post_exit_hook = post_exit_hook
+        .map(|hook| {
+            hook_environment
+                .as_ref()
+                .map_or(hook.clone(), |env| env.expand(&hook))
+        })
         .filter(|hook_command| !hook_command.is_empty());
 
     // Any options.txt settings that we want set, add here
@@ -919,7 +974,7 @@ async fn run_credentials(
 
     crate::launcher::launch_minecraft(
         &java_args,
-        &env_args,
+        &launch_env_args,
         &mc_set_options,
         &wrapper,
         &memory,