Improve tier 3 target handling: use assertFixable and smart getInstalledTargets

Co-authored-by: kraenhansen <[email protected]>

Author: Copilot

packages/ferric/src/rustup.ts

@@ -2,15 +2,58 @@ import cp from "node:child_process";
 
 import { UsageError } from "@react-native-node-api/cli-utils";
 
+/**
+ * Tier 3 targets that require build-std (defined here to avoid circular imports)
+ */
+const TIER_3_TARGETS = [
+  "aarch64-apple-visionos",
+  "aarch64-apple-visionos-sim",
+] as const;
+
+/**
+ * Check if nightly Rust with rust-src component is available for build-std
+ */
+function isBuildStdAvailable(): boolean {
+  try {
+    // Check if nightly toolchain is available
+    const toolchains = cp.execFileSync("rustup", ["toolchain", "list"], {
+      encoding: "utf-8",
+    });
+    
+    if (!toolchains.includes("nightly")) {
+      return false;
+    }
+
+    // Check if rust-src component is installed for nightly
+    const components = cp.execFileSync("rustup", ["component", "list", "--toolchain", "nightly"], {
+      encoding: "utf-8",
+    });
+
+    return components.includes("rust-src (installed)");
+  } catch {
+    return false;
+  }
+}
+
 export function getInstalledTargets() {
   try {
-    return new Set(
+    const installedTargets = new Set(
       cp
         .execFileSync("rustup", ["target", "list", "--installed"], {
           encoding: "utf-8",
         })
-        .split("\n"),
+        .split("\n")
+        .filter((line) => line.trim() !== ""),
     );
+
+    // Add tier 3 targets if build-std is properly configured
+    if (isBuildStdAvailable()) {
+      for (const target of TIER_3_TARGETS) {
+        installedTargets.add(target);
+      }
+    }
+
+    return installedTargets;
   } catch (error) {
     throw new UsageError(
       "You need a Rust toolchain: https://doc.rust-lang.org/cargo/getting-started/installation.html#install-rust-and-cargo",

packages/ferric/src/targets.ts

@@ -1,4 +1,4 @@
-import { chalk, UsageError } from "@react-native-node-api/cli-utils";
+import { chalk, UsageError, assertFixable } from "@react-native-node-api/cli-utils";
 import { getInstalledTargets } from "./rustup.js";
 
 export const ANDROID_TARGETS = [
@@ -65,7 +65,7 @@ export const TIER_3_TARGETS: readonly TargetName[] = [
  * Check if a target is a tier 3 target that requires build-std
  */
 export function isTier3Target(target: TargetName): boolean {
-  return TIER_3_TARGETS.includes(target);
+  return (TIER_3_TARGETS as readonly string[]).includes(target);
 }
 
 /**
@@ -84,20 +84,25 @@ export function ensureInstalledTargets(expectedTargets: Set<TargetName>) {
   ]);
 
   // Handle standard targets that can be installed via rustup
-  if (missingStandardTargets.size > 0) {
-    throw new UsageError(
-      `You're missing ${
-        missingStandardTargets.size
-      } targets - to fix this, run:\n\n${chalk.italic(
-        `rustup target add ${[...missingStandardTargets].join(" ")}`,
-      )}`,
-    );
-  }
+  assertFixable(
+    missingStandardTargets.size === 0,
+    `You're missing ${missingStandardTargets.size} targets`,
+    {
+      command: `rustup target add ${[...missingStandardTargets].join(" ")}`,
+    },
+  );
 
   // Handle tier 3 targets that require build-std setup
-  if (tier3Targets.size > 0) {
-    throw new UsageError(
-      `You're using tier 3 targets (${[...tier3Targets].join(", ")}) that require building the standard library from source.\n\n` +
+  // Check if tier 3 targets are properly configured (included in installedTargets means they're available)
+  const missingTier3Targets = new Set([
+    ...[...tier3Targets].filter((target) => !installedTargets.has(target)),
+  ]);
+
+  assertFixable(
+    missingTier3Targets.size === 0,
+    `You're using tier 3 targets (${[...missingTier3Targets].join(", ")}) that require building the standard library from source`,
+    {
+      instructions:
         `To set up support for these targets:\n\n` +
         `1. Install nightly Rust with the rust-src component:\n` +
         `   ${chalk.italic("rustup toolchain install nightly --component rust-src")}\n\n` +
@@ -109,8 +114,8 @@ export function ensureInstalledTargets(expectedTargets: Set<TargetName>) {
         `For more information, see:\n` +
         `- Rust Platform Support: ${chalk.italic("https://doc.rust-lang.org/rustc/platform-support.html")}\n` +
         `- Cargo build-std: ${chalk.italic("https://doc.rust-lang.org/cargo/reference/unstable.html#build-std")}`,
-    );
-  }
+    },
+  );
 }
 
 export function isAndroidTarget(