Add schemars::JsonSchema trait to ipc types (#536)

* feat: add schemars JsonSchema trait to ipc types

* niri-ipc: use feature-flag for deriving schemars::JsonSchema

---------

Co-authored-by: Ivan Molodetskikh <yalterz@gmail.com>

3 files changed, 63 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 87165de1..c22bd250 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -986,6 +986,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "dyn-clone"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d6ef0072f8a535281e4876be788938b528e9a1d43900b82c2569af7da799125"
+
+[[package]]
 name = "edid-rs"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2294,6 +2300,7 @@ name = "niri-ipc"
 version = "0.1.7"
 dependencies = [
  "clap",
+ "schemars",
  "serde",
  "serde_json",
 ]
@@ -3308,6 +3315,30 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b53b0a5db882a8e2fdaae0a43f7b39e7e9082389e978398bdf223a55b581248"
 
 [[package]]
+name = "schemars"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09c024468a378b7e36765cd36702b7a90cc3cba11654f6685c8f233408e89e92"
+dependencies = [
+ "dyn-clone",
+ "schemars_derive",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "schemars_derive"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1eee588578aff73f856ab961cd2f79e36bc45d7ded33a7562adba4667aecc0e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "serde_derive_internals",
+ "syn 2.0.67",
+]
+
+[[package]]
 name = "scoped-tls"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -3346,6 +3377,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "serde_derive_internals"
+version = "0.29.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18d26a20a969b9e3fdf2fc2d9f21eda6c40e2de84c9408bb5d3b05d499aae711"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.67",
+]
+
+[[package]]
 name = "serde_json"
 version = "1.0.120"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/niri-ipc/Cargo.toml b/niri-ipc/Cargo.toml
index e0963116..1861799a 100644
--- a/niri-ipc/Cargo.toml
+++ b/niri-ipc/Cargo.toml
@@ -9,8 +9,10 @@ repository.workspace = true
 
 [dependencies]
 clap = { workspace = true, optional = true }
+schemars = { version = "0.8.21", optional = true }
 serde.workspace = true
 serde_json.workspace = true
 
 [features]
 clap = ["dep:clap"]
+json-schema = ["dep:schemars"]
diff --git a/niri-ipc/src/lib.rs b/niri-ipc/src/lib.rs
index 16817df3..7317436c 100644
--- a/niri-ipc/src/lib.rs
+++ b/niri-ipc/src/lib.rs
@@ -11,6 +11,7 @@ pub use socket::{Socket, SOCKET_PATH_ENV};
 
 /// Request from client to niri.
 #[derive(Debug, Serialize, Deserialize, Clone)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum Request {
     /// Request the version string for the running niri instance.
     Version,
@@ -51,6 +52,7 @@ pub type Reply = Result<Response, String>;
 
 /// Successful response from niri to client.
 #[derive(Debug, Serialize, Deserialize, Clone)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum Response {
     /// A request that does not need a response was handled successfully.
     Handled,
@@ -77,6 +79,7 @@ pub enum Response {
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
 #[cfg_attr(feature = "clap", command(subcommand_value_name = "ACTION"))]
 #[cfg_attr(feature = "clap", command(subcommand_help_heading = "Actions"))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum Action {
     /// Exit niri.
     Quit {
@@ -278,6 +281,7 @@ pub enum Action {
 
 /// Change in window or column size.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum SizeChange {
     /// Set the size in logical pixels.
     SetFixed(i32),
@@ -291,6 +295,7 @@ pub enum SizeChange {
 
 /// Workspace reference (index or name) to operate on.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum WorkspaceReferenceArg {
     /// Index of the workspace.
     Index(u8),
@@ -300,6 +305,7 @@ pub enum WorkspaceReferenceArg {
 
 /// Layout to switch to.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum LayoutSwitchTarget {
     /// The next configured layout.
     Next,
@@ -314,6 +320,7 @@ pub enum LayoutSwitchTarget {
 #[cfg_attr(feature = "clap", derive(clap::Parser))]
 #[cfg_attr(feature = "clap", command(subcommand_value_name = "ACTION"))]
 #[cfg_attr(feature = "clap", command(subcommand_help_heading = "Actions"))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum OutputAction {
     /// Turn off the output.
     Off,
@@ -362,6 +369,7 @@ pub enum OutputAction {
 
 /// Output mode to set.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum ModeToSet {
     /// Niri will pick the mode automatically.
     Automatic,
@@ -371,6 +379,7 @@ pub enum ModeToSet {
 
 /// Output mode as set in the config file.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct ConfiguredMode {
     /// Width in physical pixels.
     pub width: u16,
@@ -382,6 +391,7 @@ pub struct ConfiguredMode {
 
 /// Output scale to set.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum ScaleToSet {
     /// Niri will pick the scale automatically.
     Automatic,
@@ -394,6 +404,7 @@ pub enum ScaleToSet {
 #[cfg_attr(feature = "clap", derive(clap::Subcommand))]
 #[cfg_attr(feature = "clap", command(subcommand_value_name = "POSITION"))]
 #[cfg_attr(feature = "clap", command(subcommand_help_heading = "Position Values"))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum PositionToSet {
     /// Position the output automatically.
     #[cfg_attr(feature = "clap", command(name = "auto"))]
@@ -406,6 +417,7 @@ pub enum PositionToSet {
 /// Output position as set in the config file.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq)]
 #[cfg_attr(feature = "clap", derive(clap::Args))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct ConfiguredPosition {
     /// Logical X position.
     pub x: i32,
@@ -415,6 +427,7 @@ pub struct ConfiguredPosition {
 
 /// Connected output.
 #[derive(Debug, Serialize, Deserialize, Clone)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct Output {
     /// Name of the output.
     pub name: String,
@@ -442,6 +455,7 @@ pub struct Output {
 
 /// Output mode.
 #[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct Mode {
     /// Width in physical pixels.
     pub width: u16,
@@ -455,6 +469,7 @@ pub struct Mode {
 
 /// Logical output in the compositor's coordinate space.
 #[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct LogicalOutput {
     /// Logical X position.
     pub x: i32,
@@ -473,6 +488,7 @@ pub struct LogicalOutput {
 /// Output transform, which goes counter-clockwise.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "clap", derive(clap::ValueEnum))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum Transform {
     /// Untransformed.
     Normal,
@@ -500,6 +516,7 @@ pub enum Transform {
 
 /// Toplevel window.
 #[derive(Serialize, Deserialize, Debug, Clone)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct Window {
     /// Title, if set.
     pub title: Option<String>,
@@ -509,6 +526,7 @@ pub struct Window {
 
 /// Output configuration change result.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub enum OutputConfigChanged {
     /// The target output was connected and the change was applied.
     Applied,
@@ -518,6 +536,7 @@ pub enum OutputConfigChanged {
 
 /// A workspace.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
 pub struct Workspace {
     /// Index of the workspace on its monitor.
     ///