feat: studio.theme.solarized v0.1.0 builds against SDK

Promotes the skeleton to a real WASM plugin component. The
22 KiB stripped artefact at
target/wasm32-wasip2/release/studio_theme_solarized.wasm
is the proof-of-contract for fai-studio-plugin-sdk v0.1.

Implements:

- theme::Guest::theme_for(brightness) returning the
  pinned Solarized Light/Dark palettes (14 ARGB tokens
  each). Brightness names other than "light"/"dark"
  return PluginError::Declined.
- translate::Guest + output_view::Guest as Declined-only
  stubs — v0.1 of the SDK requires all three hooks per
  plugin; v0.2 will split the WIT.

Cargo.toml pins edition 2021 (matches SDK; wit-bindgen
0.36 codegen does not yet support edition 2024).

Signed-off-by: flemming-it <sf@flemming.it>

src/lib.rs

@@ -1,24 +1,23 @@
 //! `studio.theme.solarized` — first Studio plugin.
 //!
 //! Ships Ethan Schoonover's Solarized palette as a Material 3
-//! ColorScheme pair (light + dark).
+//! ColorScheme pair (light + dark) through the WIT `theme`
+//! export.
 //!
-//! SKELETON: this file does not yet compile. The
-//! `#[plugin(theme)]` macro and the `studio_plugin` runtime live
-//! in `fai-studio-plugin-sdk`, which is documented in
-//! `docs/advanced/studio-plugin-sdk.md` but not yet implemented.
-//! Once the SDK ships, switching the file from skeleton to
-//! buildable is a matter of uncommenting the dependency in
-//! Cargo.toml and the use-line below.
-//!
-//! Why ship the skeleton now: pins the palette so the in-tree
-//! reference plugin doesn't bike-shed at SDK-integration time,
-//! and gives the SDK author a concrete consumer to validate
-//! their generated macro output against.
+//! This is the proof-of-contract plugin for the
+//! `fai-studio-plugin-sdk` v0.1 shape: one struct, one
+//! `Guest` impl, one `export_plugin!` invocation.
 
-#![allow(dead_code, unused_imports)]
+#![allow(clippy::result_large_err)]
 
-// use fai_studio_plugin_sdk::{plugin, theme, ColorScheme};
+use fai_studio_plugin_sdk::{bindings, export_plugin};
+
+// Type aliases against the SDK's bindings so the impl block
+// reads cleanly. Once the SDK v0.2 ships proper re-exports +
+// world-per-hook, these collapse to a single `use` line.
+type ColorScheme = bindings::fai::studio_plugin::plugin_types::ColorScheme;
+type PluginError = bindings::fai::studio_plugin::plugin_types::PluginError;
+type RenderedOutput = bindings::fai::studio_plugin::plugin_types::RenderedOutput;
 
 /// 14 ARGB tokens, Material 3 order:
 ///   primary, on_primary, secondary, on_secondary,
@@ -26,8 +25,8 @@
 ///   surface, on_surface, surface_variant, on_surface_variant,
 ///   outline, outline_variant.
 ///
-/// Studio merges any missing slot (we send all 14, so none) with
-/// its built-in fallback before applying.
+/// Studio merges any missing slot (we send all 14, so none)
+/// with its built-in fallback before applying.
 const SOLARIZED_LIGHT: [u32; 14] = [
     0xFF268BD2, // primary           — solarized blue
     0xFFFDF6E3, // on_primary        — base3
@@ -62,45 +61,54 @@ const SOLARIZED_DARK: [u32; 14] = [
     0xFF073642, // outline_variant   — base02
 ];
 
-// ─────────────────────────────────────────────────────────────
-// Forward-reference: this is the shape the SDK will generate
-// from `#[plugin(theme)]`. Once the SDK exists, the body collapses
-// to a return of `Ok(ColorScheme { brightness, tokens: … })`.
-// ─────────────────────────────────────────────────────────────
-//
-// #[plugin(theme)]
-// fn theme_for(brightness: &str) -> theme::Result {
-//     let tokens = match brightness {
-//         "light" => SOLARIZED_LIGHT.to_vec(),
-//         "dark"  => SOLARIZED_DARK.to_vec(),
-//         other => {
-//             return Err(theme::Error::declined(format!(
-//                 "solarized has no scheme for brightness '{other}'",
-//             )))
-//         }
-//     };
-//     Ok(ColorScheme {
-//         brightness: brightness.to_string(),
-//         tokens,
-//     })
-// }
+/// The plugin component. Holds no state — every theme-for
+/// call computes from the brightness arg alone.
+struct SolarizedPlugin;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn palette_has_14_tokens() {
-        assert_eq!(SOLARIZED_LIGHT.len(), 14);
-        assert_eq!(SOLARIZED_DARK.len(), 14);
-    }
-
-    #[test]
-    fn solarized_blue_is_the_primary_in_both_modes() {
-        // Ethan Schoonover's blue is the brand colour of
-        // Solarized. Sanity-check we kept it as the primary in
-        // both schemes.
-        assert_eq!(SOLARIZED_LIGHT[0], 0xFF268BD2);
-        assert_eq!(SOLARIZED_DARK[0], 0xFF268BD2);
+impl bindings::exports::fai::studio_plugin::theme::Guest for SolarizedPlugin {
+    fn theme_for(brightness: String) -> Result<ColorScheme, PluginError> {
+        let tokens = match brightness.as_str() {
+            "light" => SOLARIZED_LIGHT.to_vec(),
+            "dark" => SOLARIZED_DARK.to_vec(),
+            other => {
+                return Err(PluginError::Declined(format!(
+                    "solarized has no scheme for brightness '{other}' \
+                     (supported: light, dark)"
+                )));
+            }
+        };
+        Ok(ColorScheme { brightness, tokens })
     }
 }
+
+// SDK v0.1 wraps all three hooks in a single WIT world, so a
+// plugin that only really cares about `theme` still has to
+// declare empty / declined impls for the other two. v0.2 will
+// split the WIT into one world per hook; until then these
+// `declined` returns are the right answer — Studio falls back
+// to its built-in renderer or to the [EN] badge.
+
+impl bindings::exports::fai::studio_plugin::translate::Guest for SolarizedPlugin {
+    fn translate(
+        _text: String,
+        _from_locale: String,
+        _to_locale: String,
+    ) -> Result<String, PluginError> {
+        Err(PluginError::Declined(
+            "solarized is a theme plugin and does not translate".to_string(),
+        ))
+    }
+}
+
+impl bindings::exports::fai::studio_plugin::output_view::Guest for SolarizedPlugin {
+    fn render(
+        _mime_type: String,
+        _data: Vec<u8>,
+    ) -> Result<RenderedOutput, PluginError> {
+        Err(PluginError::Declined(
+            "solarized is a theme plugin and does not render outputs".to_string(),
+        ))
+    }
+}
+
+export_plugin!(SolarizedPlugin);