fix: inject VP_COMMAND in Rust resolver for synthesized subcommands

When vp run synthesizes inner commands like vp build, VP_COMMAND
stayed as 'run' from the parent process, causing defineConfig to
skip the plugins factory. Now the resolver injects VP_COMMAND with
the actual subcommand name into child process envs.

Author: fengmk2

packages/cli/binding/src/cli.rs

@@ -123,6 +123,24 @@ pub enum SynthesizableSubcommand {
     },
 }
 
+impl SynthesizableSubcommand {
+    /// Return the command name string for use in `VP_COMMAND` env var.
+    fn command_name(&self) -> &'static str {
+        match self {
+            Self::Lint { .. } => "lint",
+            Self::Fmt { .. } => "fmt",
+            Self::Build { .. } => "build",
+            Self::Test { .. } => "test",
+            Self::Pack { .. } => "pack",
+            Self::Dev { .. } => "dev",
+            Self::Preview { .. } => "preview",
+            Self::Doc { .. } => "doc",
+            Self::Install { .. } => "install",
+            Self::Check { .. } => "check",
+        }
+    }
+}
+
 /// Top-level CLI argument parser for vite-plus.
 #[derive(Debug, Parser)]
 #[command(name = "vp", disable_help_subcommand = true)]
@@ -233,6 +251,22 @@ impl SubcommandResolver {
         resolved_vite_config: Option<&ResolvedUniversalViteConfig>,
         envs: &Arc<FxHashMap<Arc<OsStr>, Arc<OsStr>>>,
         cwd: &Arc<AbsolutePath>,
+    ) -> anyhow::Result<ResolvedSubcommand> {
+        let command_name = subcommand.command_name();
+        let mut resolved = self.resolve_inner(subcommand, resolved_vite_config, envs, cwd).await?;
+        // Inject VP_COMMAND so that defineConfig's plugin factory knows which command is running,
+        // even when the subcommand is synthesized inside `vp run`.
+        let envs = Arc::make_mut(&mut resolved.envs);
+        envs.insert(Arc::from(OsStr::new("VP_COMMAND")), Arc::from(OsStr::new(command_name)));
+        Ok(resolved)
+    }
+
+    async fn resolve_inner(
+        &self,
+        subcommand: SynthesizableSubcommand,
+        resolved_vite_config: Option<&ResolvedUniversalViteConfig>,
+        envs: &Arc<FxHashMap<Arc<OsStr>, Arc<OsStr>>>,
+        cwd: &Arc<AbsolutePath>,
     ) -> anyhow::Result<ResolvedSubcommand> {
         match subcommand {
             SynthesizableSubcommand::Lint { mut args } => {

packages/cli/snap-tests/vite-plugins-run-build/snap.txt

@@ -1,2 +1,3 @@
 > vp run build-task
-[1]> cat dist/index.html | grep 'run-build-plugin-injected' # vp run build should load plugins from factory
+> cat dist/index.html | grep 'run-build-plugin-injected' # vp run build should load plugins from factory
+  <!-- run-build-plugin-injected --></body>