chore: import upstream snapshot with attribution

packages/transformers/scripts/dev.mjs

@@ -0,0 +1,113 @@
+import { spawn } from "node:child_process";
+import { unlinkSync } from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { OUT_DIR } from "./build/constants.mjs";
+import prepareOutDir from "../../../scripts/prepareOutDir.mjs";
+import { colors, createLogger } from "../../../scripts/logger.mjs";
+import { buildAllWithWatch } from "./build/buildAllWithWatch.mjs";
+
+const log = createLogger("transformers");
+const startTime = performance.now();
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const ROOT_DIR = path.join(__dirname, "..");
+
+prepareOutDir(OUT_DIR);
+
+// Remove tsbuildinfo to force TypeScript to rebuild type declarations
+try {
+  unlinkSync(`${ROOT_DIR}/types/tsconfig.tsbuildinfo`);
+} catch (err) {
+  // File doesn't exist, that's fine
+}
+
+log.section("BUILD");
+log.info("Building transformers.js with esbuild in watch mode...");
+
+// Build all targets with watch mode
+const contexts = await buildAllWithWatch(log);
+
+const endTime = performance.now();
+const duration = (endTime - startTime).toFixed(2);
+log.success(`All builds completed in ${colors.bright}${duration}ms${colors.reset}`);
+
+// Generate initial TypeScript declarations, then start watch mode
+log.section("TYPES");
+log.info("Generating initial type declarations...");
+
+await new Promise((resolve, reject) => {
+  const tscBuild = spawn("tsc", ["--build"], {
+    cwd: ROOT_DIR,
+    stdio: "pipe",
+    shell: true,
+  });
+
+  tscBuild.stdout.on("data", (data) => {
+    const output = data.toString().trim();
+    if (output && output.includes("error")) {
+      log.dim(output);
+    }
+  });
+
+  tscBuild.stderr.on("data", (data) => {
+    const output = data.toString().trim();
+    if (output) {
+      log.error(output);
+    }
+  });
+
+  tscBuild.on("exit", (code) => {
+    if (code === 0) {
+      log.done("Type declarations generated");
+      resolve();
+    } else {
+      reject(new Error(`TypeScript build failed with code ${code}`));
+    }
+  });
+});
+
+log.info("Starting TypeScript watch mode...\n");
+
+const tscWatch = spawn("tsc", ["--build", "--watch", "--preserveWatchOutput"], {
+  cwd: ROOT_DIR,
+  stdio: "pipe",
+  shell: true,
+});
+
+tscWatch.stdout.on("data", (data) => {
+  const output = data.toString().trim();
+  if (output) {
+    output.split("\n").forEach((line) => {
+      // Filter out verbose output, only show important messages
+      if (
+        line.includes("error") ||
+        line.includes("File change detected") ||
+        line.includes("Found 0 errors") ||
+        (line.includes("Found") && line.includes("error"))
+      ) {
+        log.dim(line);
+      }
+    });
+  }
+});
+
+tscWatch.stderr.on("data", (data) => {
+  const output = data.toString().trim();
+  if (output) {
+    output.split("\n").forEach((line) => {
+      log.error(line);
+    });
+  }
+});
+
+log.dim(`Watching for changes...\n`);
+
+// Keep process alive and cleanup
+process.on("SIGINT", async () => {
+  log.warning(`\nStopping watch mode...`);
+  tscWatch.kill();
+  await Promise.all(contexts.map((ctx) => ctx.dispose()));
+  log.dim("Goodbye!");
+  process.exit(0);
+});