fix: explicitly provide path to babel plugins (#3482)

feywind · web-flow · commit 6d34a3d99725 · 2022-11-03T16:46:18.000-04:00
* fix: explicitly provide path to babel plugins

* docs: add a comment explaining the path stuff
diff --git a/packages/typeless-sample-bot/src/app.ts b/packages/typeless-sample-bot/src/app.ts
@@ -26,7 +26,6 @@ import {
   waitForAllSamples,
   fromArray,
 } from './samples.js';
-import url from 'node:url';
 
 let returnValue = 0;
 
diff --git a/packages/typeless-sample-bot/src/import-to-require.ts b/packages/typeless-sample-bot/src/import-to-require.ts
@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Reference notes:
 // https://lihautan.com/step-by-step-guide-for-writing-a-babel-transformation/
 // https://lihautan.com/babel-ast-explorer/
 // https://github.com/esamattis/babel-plugin-ts-optchain/blob/master/packages/babel-plugin-ts-optchain/src/plugin.ts
diff --git a/packages/typeless-sample-bot/src/samples.ts b/packages/typeless-sample-bot/src/samples.ts
@@ -80,10 +80,24 @@ export async function* filterByContents(
 
 // Instead of a babelrc, this is used so that we can get more control over
 // the transform process.
+//
+// The heavy path manipulation is required here to work around a problem
+// with finding Babel plugins on the path when running the bot from
+// outside its own tree. Babel will attempt to resolve plugins to
+// the most proximate node_modules, which will be the package being
+// operated upon, not us.
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const ptPath = path.join(
+  __dirname,
+  '..',
+  '..',
+  'node_modules',
+  '@babel',
+  'preset-typescript'
+);
 const itrPath = path.join(__dirname, 'import-to-require');
 const babelConfig = {
-  presets: [['@babel/preset-typescript', {}]],
+  presets: [[ptPath, {}]],
   plugins: [[itrPath]],
   parserOpts: {} as babel.ParserOptions,
   generatorOpts: {
