Add write file and baseDir to transform

Also add error handling for transformers

Author: willemneal

cli/asc.js

@@ -224,7 +224,11 @@ exports.main = function main(argv, options, callback) {
   }
   function applyTransform(name, ...args) {
     transforms.forEach(transform => {
-      if (typeof transform[name] === "function") transform[name](...args);
+      try {
+        if (typeof transform[name] === "function") transform[name](...args);
+      } catch (e) {
+        callback(e);
+      }
     });
   }
 
@@ -426,7 +430,7 @@ exports.main = function main(argv, options, callback) {
   }
 
   // Call afterParse transform hook
-  applyTransform("afterParse", parser);
+  applyTransform("afterParse", parser, writeFile, baseDir);
 
   // Parse additional files, if any
   {

cli/transform.d.ts

@@ -5,7 +5,8 @@
 
 import { Parser } from "../src/parser";
 
+declare function writeFile(name: string, contents: string | Uint8Array, baseDir: string): void;
 export interface Transform {
   /** Called when parsing is complete, before a program is instantiated from the AST. */
-  afterParse(parser: Parser): void;
+  afterParse(parser: Parser, writer?: typeof writeFile, baseDir?: string): void;
 }