Migrate Babel from Flow to TypeScript (except Babel parser) (#11578)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

packages/babel-node/src/babel-node.ts

@@ -0,0 +1,109 @@
+/**
+ * This tiny wrapper file checks for known node flags and appends them
+ * when found, before invoking the "real" _babel-node(1) executable.
+ */
+
+import getV8Flags from "v8flags";
+import path from "path";
+import child_process from "child_process";
+import { fileURLToPath } from "url";
+
+const args = [
+  path.join(path.dirname(fileURLToPath(import.meta.url)), "_babel-node"),
+];
+
+let babelArgs = process.argv.slice(2);
+let userArgs;
+
+// separate node arguments from script arguments
+const argSeparator = babelArgs.indexOf("--");
+if (argSeparator > -1) {
+  userArgs = babelArgs.slice(argSeparator); // including the  --
+  babelArgs = babelArgs.slice(0, argSeparator);
+}
+
+/**
+ * Replace dashes with underscores in the v8Flag name
+ * Also ensure that if the arg contains a value (e.g. --arg=true)
+ * that only the flag is returned.
+ */
+function getNormalizedV8Flag(arg) {
+  // v8 uses the "no" prefix to negate boolean flags (e.g. --nolazy),
+  // but they are not listed by v8flags
+  const matches = arg.match(/--(?:no)?(.+)/);
+
+  if (matches) {
+    return `--${matches[1].replace(/-/g, "_")}`;
+  }
+
+  return arg;
+}
+
+// These are aliases for node options defined by babel-node.
+const aliases = new Map([
+  ["-d", "--debug"],
+  ["-gc", "--expose-gc"],
+]);
+
+getV8Flags(async function (err, v8Flags) {
+  for (let i = 0; i < babelArgs.length; i++) {
+    const arg = babelArgs[i];
+    const flag = arg.split("=")[0];
+
+    if (flag === "-r" || flag === "--require") {
+      args.push(flag);
+      args.push(babelArgs[++i]);
+    } else if (aliases.has(flag)) {
+      args.unshift(aliases.get(flag));
+    } else if (
+      flag === "debug" || // node debug foo.js
+      flag === "inspect" ||
+      v8Flags.indexOf(getNormalizedV8Flag(flag)) >= 0 ||
+      process.allowedNodeEnvironmentFlags.has(flag)
+    ) {
+      args.unshift(arg);
+    } else {
+      args.push(arg);
+    }
+  }
+
+  // append arguments passed after --
+  if (argSeparator > -1) {
+    args.push(...userArgs);
+  }
+
+  try {
+    const { default: kexec } = await import("kexec");
+    kexec(process.argv[0], args);
+  } catch (err) {
+    if (
+      err.code !== "ERR_MODULE_NOT_FOUND" &&
+      err.code !== "MODULE_NOT_FOUND" &&
+      err.code !== "UNDECLARED_DEPENDENCY"
+    ) {
+      throw err;
+    }
+
+    // passthrough IPC only if babel-node itself has an IPC channel
+    const shouldPassthroughIPC = process.send !== undefined;
+    const proc = child_process.spawn(process.argv[0], args, {
+      stdio: shouldPassthroughIPC
+        ? ["inherit", "inherit", "inherit", "ipc"]
+        : "inherit",
+    });
+    proc.on("exit", function (code, signal) {
+      process.on("exit", function () {
+        if (signal) {
+          process.kill(process.pid, signal);
+        } else {
+          process.exitCode = code;
+        }
+      });
+    });
+    if (shouldPassthroughIPC) {
+      proc.on("message", message => process.send(message));
+    }
+    process.on("SIGINT", () => proc.kill("SIGINT"));
+    process.on("SIGTERM", () => proc.kill("SIGTERM"));
+  }
+});