feat(transform-eventual-send): expose bare transform function too

bundle-source will use this function, which doesn't include the endowments
and HandledPromise stuff that's in the default export (which is aimed at the
SES1 transformers list)

packages/transform-eventual-send/src/index.js

@@ -1,6 +1,28 @@
 import eventualSendBundle from './bundles/eventual-send';
 
+export function makeTransform(parser, generate) {
+  function transform(source) {
+    // Parse with eventualSend enabled, rewriting to
+    // HandledPromise.get/applyFunction/applyMethod(...). Whoever finally
+    // evaluates this code must provide a HandledPromise object, probably as
+    // an endowment.
+    const parseFunc = parser.parse;
+    const ast = (parseFunc || parser)(source, {
+      sourceType: 'module',
+      plugins: ['eventualSend'],
+    });
+    // Create the source from the ast.
+    const output = generate(ast, { retainLines: true }, source);
+    return output.code;
+  }
+  return transform;
+}
+
+// this transformer is meant for the SES1 evaluation format, with mutable
+// endowments and stuff
+
 function makeEventualSendTransformer(parser, generate) {
+  const transformer = makeTransform(parser, generate);
   let HandledPromise;
   let evaluateProgram;
   let myRequire;
@@ -57,17 +79,9 @@ function makeEventualSendTransformer(parser, generate) {
         });
       }
 
-      // Parse with eventualSend enabled, rewriting to
-      // HandledPromise.get/applyFunction/applyMethod(...)
-      const parseFunc = parser.parse;
-      const ast = (parseFunc || parser)(source, {
-        plugins: ['eventualSend'],
-      });
-      // Create the source from the ast.
-      const output = generate(ast, { retainLines: true }, source);
+      const maybeSource = transformer(source);
 
       // Work around Babel appending semicolons.
-      const maybeSource = output.code;
       const actualSource =
         ss.sourceType === 'expression' &&
         maybeSource.endsWith(';') &&
@@ -77,7 +91,6 @@ function makeEventualSendTransformer(parser, generate) {
 
       return {
         ...ss,
-        ast,
         endowments,
         src: actualSource,
       };

packages/transform-eventual-send/test/test-transformer.js

@@ -0,0 +1,15 @@
+import { test } from 'tape';
+import * as babelParser from '@agoric/babel-parser';
+import babelGenerate from '@babel/generator';
+import { makeTransform } from '../src';
+
+test('transformer', t => {
+  const source = `let p = bob~.foo(arg1, arg2);`;
+  const transformer = makeTransform(babelParser, babelGenerate);
+  const output = transformer(source);
+  t.equal(
+    output,
+    `let p = HandledPromise.applyMethod(bob, "foo", [arg1, arg2]);`,
+  );
+  t.end();
+});