api: provide an error when the output does not exist where to add an tag

api/lua/pinnacle/grpc/defs.lua

@@ -1334,6 +1334,10 @@ local pinnacle_v1_Backend = {
 
 ---@class pinnacle.tag.v1.AddResponse
 ---@field tag_ids integer[]?
+---@field error pinnacle.tag.v1.AddResponse.Error?
+
+---@class pinnacle.tag.v1.AddResponse.Error
+---@field output_does_not_exist google.protobuf.Empty?
 
 ---@class pinnacle.tag.v1.RemoveRequest
 ---@field tag_ids integer[]?
@@ -1613,6 +1617,7 @@ pinnacle.tag.v1.GetRequest = {}
 pinnacle.tag.v1.GetResponse = {}
 pinnacle.tag.v1.AddRequest = {}
 pinnacle.tag.v1.AddResponse = {}
+pinnacle.tag.v1.AddResponse.Error = {}
 pinnacle.tag.v1.RemoveRequest = {}
 pinnacle.tag.v1.MoveToOutputRequest = {}
 pinnacle.tag.v1.MoveToOutputResponse = {}

api/lua/pinnacle/tag.lua

@@ -139,6 +139,7 @@ end
 ---@param ... string The names of the new tags.
 ---
 ---@return pinnacle.tag.TagHandle[] tags Handles to the created tags.
+---@return pinnacle.tag.AddError|nil err Error on failure.
 ---
 ---@overload fun(output: pinnacle.output.OutputHandle, tag_names: string[]): pinnacle.tag.TagHandle[]
 function tag.add(output, ...)
@@ -154,11 +155,15 @@ function tag.add(output, ...)
 
     if err then
         log.error(err)
-        return {}
+        return {}, nil
     end
 
     assert(response)
 
+    if response.error and response.error.output_does_not_exist then
+        return {}, { output_does_not_exist = true }
+    end
+
     ---@type pinnacle.tag.TagHandle[]
     local handles = {}
 
@@ -272,6 +277,9 @@ local signal_name_to_SignalName = {
 ---@field output_does_not_exist boolean?
 ---This operation would cause the provided windows to be on multiple outputs.
 ---@field same_window_on_two_outputs pinnacle.window.WindowHandle[]?
+---@class pinnacle.tag.AddError
+---`true` if the output does not exist.
+---@field output_does_not_exist boolean?
 
 ---Connects to a tag signal.
 ---

api/protobuf/pinnacle/tag/v1/tag.proto

@@ -15,7 +15,14 @@ message AddRequest {
     repeated string tag_names = 2;
 }
 message AddResponse {
+    message Error {
+        oneof kind {
+            google.protobuf.Empty output_does_not_exist = 1;
+        }
+    }
+
     repeated uint32 tag_ids = 1;
+    optional Error error = 2;
 }
 
 message RemoveRequest {

api/rust/examples/default_config/main.rs

@@ -386,7 +386,9 @@ async fn config() {
 
     // Setup all monitors with tags "1" through "9"
     output::for_each_output(move |output| {
-        let mut tags = tag::add(output, tag_names);
+        let Ok(mut tags) = tag::add(output, tag_names) else {
+            return;
+        };
         tags.next().unwrap().set_active(true);
     });
 

api/rust/src/output.rs

@@ -127,7 +127,7 @@ pub async fn get_focused_async() -> Option<OutputHandle> {
 /// # use pinnacle_api::tag;
 /// // Add tags 1-3 to all outputs and set tag "1" to active
 /// output::for_each_output(|op| {
-///     let mut tags = tag::add(op, ["1", "2", "3"]);
+///     let Ok(mut tags) = tag::add(op, ["1", "2", "3"]) else { return };
 ///     tags.next().unwrap().set_active(true);
 /// });
 /// ```

api/rust/src/tag.rs

@@ -28,7 +28,7 @@ use pinnacle_api_defs::pinnacle::{
     tag::v1::{
         AddRequest, GetActiveRequest, GetNameRequest, GetOutputNameRequest, GetRequest,
         MoveToOutputRequest, RemoveRequest, SetActiveRequest, SwitchToRequest,
-        move_to_output_response::error::Kind,
+        add_response::error::Kind as AddErrorKind, move_to_output_response::error::Kind,
     },
     util::v1::SetOrToggle,
 };
@@ -53,29 +53,37 @@ use crate::{
 /// # use pinnacle_api::output;
 /// # use pinnacle_api::tag;
 /// // Add tags 1-5 to the focused output
-/// if let Some(op) = output::get_focused() {
-///     let tags = tag::add(&op, ["1", "2", "3", "4", "5"]);
-/// }
+/// # || -> Result<(), tag::AddError> {
+/// let Some(op) = output::get_focused() else { return Ok(()); };
+/// let tags = tag::add(&op, ["1", "2", "3", "4", "5"])?;
+/// # Ok(())
+/// # };
 /// ```
-pub fn add<I, T>(output: &OutputHandle, tag_names: I) -> impl Iterator<Item = TagHandle> + use<I, T>
+pub fn add<I, T>(
+    output: &OutputHandle,
+    tag_names: I,
+) -> Result<impl Iterator<Item = TagHandle> + use<I, T>, AddError>
 where
     I: IntoIterator<Item = T>,
     T: ToString,
 {
     let output_name = output.name();
     let tag_names = tag_names.into_iter().map(|name| name.to_string()).collect();
 
-    Client::tag()
+    let response = Client::tag()
         .add(AddRequest {
             output_name,
             tag_names,
         })
         .block_on_tokio()
         .unwrap()
-        .into_inner()
-        .tag_ids
-        .into_iter()
-        .map(|id| TagHandle { id })
+        .into_inner();
+
+    let error = response.error.and_then(|error| error.kind);
+    match error {
+        None => Ok(response.tag_ids.into_iter().map(|id| TagHandle { id })),
+        Some(AddErrorKind::OutputDoesNotExist(_)) => Err(AddError::OutputDoesNotExist),
+    }
 }
 
 /// Gets handles to all tags across all outputs.
@@ -167,7 +175,7 @@ pub async fn get_on_output_async(name: impl ToString, output: &OutputHandle) ->
 /// # use pinnacle_api::tag;
 /// # use pinnacle_api::output;
 /// # || {
-/// let tags = tag::add(&output::get_by_name("DP-1")?, ["1", "2", "Buckle", "Shoe"]);
+/// let tags = tag::add(&output::get_by_name("DP-1")?, ["1", "2", "Buckle", "Shoe"]).ok()?;
 ///
 /// tag::remove(tags); // "DP-1" no longer has any tags
 /// # Some(())
@@ -240,6 +248,13 @@ where
     }
 }
 
+/// Error that happens when adding tags to a different output.
+#[derive(Debug, PartialEq, Clone)]
+pub enum AddError {
+    /// The requested output to add tags to, does not exist
+    OutputDoesNotExist,
+}
+
 /// Connects to a [`TagSignal`].
 ///
 /// # Examples
@@ -390,8 +405,8 @@ impl TagHandle {
     /// # use pinnacle_api::tag;
     /// # use pinnacle_api::output;
     /// # || {
-    /// let tags =
-    ///     tag::add(&output::get_by_name("DP-1")?, ["1", "2", "Buckle", "Shoe"]).collect::<Vec<_>>();
+    /// let tags = tag::add(&output::get_by_name("DP-1")?, ["1", "2", "Buckle", "Shoe"]).ok()?
+    ///     .collect::<Vec<_>>();
     ///
     /// tags[1].remove();
     /// tags[3].remove();

src/api/tag.rs

@@ -3,7 +3,6 @@ pub mod v1;
 use std::mem;
 
 use indexmap::IndexSet;
-use tracing::warn;
 
 use crate::{
     output::OutputName,
@@ -69,13 +68,9 @@ pub fn add(
     state: &mut State,
     tag_names: impl IntoIterator<Item = String>,
     output_name: OutputName,
-) -> Vec<Tag> {
+) -> Result<Vec<Tag>, TagAddError> {
     let Some(output) = output_name.output(&state.pinnacle) else {
-        warn!(
-            "Tried to add tags to output {} but it doesn't exist",
-            output_name.0
-        );
-        return Vec::new();
+        return Err(TagAddError::OutputDoesNotExist);
     };
 
     let new_tags = tag_names.into_iter().map(Tag::new).collect::<Vec<_>>();
@@ -106,7 +101,13 @@ pub fn add(
         state.pinnacle.signal_state.tag_created.signal(tag);
     }
 
-    new_tags
+    Ok(new_tags)
+}
+
+#[derive(Debug, PartialEq, Clone)]
+pub enum TagAddError {
+    /// Its impossible to add tags to an output that does not exist. Create it first
+    OutputDoesNotExist,
 }
 
 pub fn remove(state: &mut State, tags_to_remove: Vec<Tag>) {

src/api/tag/v1.rs

@@ -131,11 +131,23 @@ impl v1::tag_service_server::TagService for super::TagService {
         let tag_names = request.tag_names;
 
         run_unary(&self.sender, move |state| {
-            let tags = crate::api::tag::add(state, tag_names, output_name);
-
-            let tag_ids = tags.into_iter().map(|tag| tag.id().to_inner()).collect();
+            use crate::api::tag::TagAddError;
+            use pinnacle_api_defs::pinnacle::tag::v1::add_response::{Error, error::Kind};
+
+            let (tag_ids, error) = match crate::api::tag::add(state, tag_names, output_name) {
+                Ok(tags) => (
+                    tags.into_iter().map(|tag| tag.id().to_inner()).collect(),
+                    None,
+                ),
+                Err(TagAddError::OutputDoesNotExist) => (
+                    Vec::new(),
+                    Some(Error {
+                        kind: Some(Kind::OutputDoesNotExist(())),
+                    }),
+                ),
+            };
 
-            Ok(AddResponse { tag_ids })
+            Ok(AddResponse { tag_ids, error })
         })
         .await
     }

src/handlers/ext_workspace.rs

@@ -1,3 +1,4 @@
+use crate::api::tag::TagAddError;
 use crate::delegate_ext_workspace;
 use crate::output::OutputName;
 use crate::protocol::ext_workspace::{ExtWorkspaceHandler, ExtWorkspaceManagerState};
@@ -28,7 +29,15 @@ impl ExtWorkspaceHandler for State {
     }
 
     fn add_workspace(&mut self, output: &Output, name: String) {
-        crate::api::tag::add(self, [name.clone()], OutputName(output.name()));
+        match crate::api::tag::add(self, [name.clone()], OutputName(output.name())) {
+            Err(TagAddError::OutputDoesNotExist) => {
+                tracing::warn!(
+                    output_name = output.name(),
+                    "Tried to add tags to output but it doesn't exist",
+                );
+            }
+            Ok(_) => (),
+        }
     }
 }
 

tests/integration/api/tag.rs

@@ -115,6 +115,7 @@ fn tag_add() {
                     &pinnacle_api::output::get_focused().unwrap(),
                     ["nubby's", "number", "factory"],
                 );
+                let tags = tags.unwrap();
                 assert_eq!(tags.count(), 3);
             }),
             Lang::Lua => spawn_lua_blocking! {

wlcs_pinnacle/src/config.rs

@@ -4,6 +4,7 @@ mod inner {
     async fn config() {
         pinnacle_api::output::for_each_output(|output| {
             pinnacle_api::tag::add(output, ["1"])
+                .unwrap()
                 .next()
                 .unwrap()
                 .set_active(true);