Rename @babel/core files to .ts (#12929)

packages/babel-core/src/transform-ast.ts

@@ -0,0 +1,61 @@
+// @flow
+
+import gensync from "gensync";
+
+import loadConfig, { type InputOptions, type ResolvedConfig } from "./config";
+import {
+  run,
+  type FileResult,
+  type FileResultCallback,
+} from "./transformation";
+
+type AstRoot = BabelNodeFile | BabelNodeProgram;
+
+type TransformFromAst = {
+  (ast: AstRoot, code: string, callback: FileResultCallback): void,
+  (
+    ast: AstRoot,
+    code: string,
+    opts: ?InputOptions,
+    callback: FileResultCallback,
+  ): void,
+
+  // Here for backward-compatibility. Ideally use ".transformSync" if you want
+  // a synchronous API.
+  (ast: AstRoot, code: string, opts: ?InputOptions): FileResult | null,
+};
+
+const transformFromAstRunner = gensync<
+  [AstRoot, string, ?InputOptions],
+  FileResult | null,
+>(function* (ast, code, opts) {
+  const config: ResolvedConfig | null = yield* loadConfig(opts);
+  if (config === null) return null;
+
+  if (!ast) throw new Error("No AST given");
+
+  return yield* run(config, code, ast);
+});
+
+export const transformFromAst: TransformFromAst = (function transformFromAst(
+  ast,
+  code,
+  opts,
+  callback,
+) {
+  if (typeof opts === "function") {
+    callback = opts;
+    opts = undefined;
+  }
+
+  // For backward-compat with Babel 6, we allow sync transformation when
+  // no callback is given. Will be dropped in some future Babel major version.
+  if (callback === undefined) {
+    return transformFromAstRunner.sync(ast, code, opts);
+  }
+
+  transformFromAstRunner.errback(ast, code, opts, callback);
+}: Function);
+
+export const transformFromAstSync = transformFromAstRunner.sync;
+export const transformFromAstAsync = transformFromAstRunner.async;