fix(sucrase): allow js files for TypeScript resolutuon (#1019)

* fix(surcase): resolve specifier with extension TypeScript allows to use `.js` in the extension to resolve files that actually end with `.ts` or `.tsx`. This commit adds support for this. * fixup! fix(surcase): resolve specifier with extension * fixup! fix(surcase): resolve specifier with extension * fixup! fix(surcase): resolve specifier with extension * fixup! fix(surcase): resolve specifier with extension * fixup! fix(surcase): resolve specifier with extension * use resolved in both places * attempt to fix the failing test Co-authored-by: Tom Jenkinson <tjenkinson@users.noreply.github.com>

Author: 2 people

packages/sucrase/src/index.js

@@ -15,12 +15,21 @@ module.exports = function sucrase(opts = {}) {
  if (importer && /^[./]/.test(importee)) {
  const resolved = path.resolve(importer ? path.dirname(importer) : process.cwd(), importee);
  // resolve in the same order that TypeScript resolves modules
- const resolvedFilename = [
+ const resolvedFilenames = [
  `${resolved}.ts`,
  `${resolved}.tsx`,
  `${resolved}/index.ts`,
  `${resolved}/index.tsx`
- ].find((filename) => fs.existsSync(filename));
+ ];
+ if (resolved.endsWith('.js')) {
+ resolvedFilenames.splice(
+ 2,
+ 0,
+ `${resolved.slice(0, -3)}.ts`,
+ `${resolved.slice(0, -3)}.tsx`
+ );
+ }
+ const resolvedFilename = resolvedFilenames.find((filename) => fs.existsSync(filename));
 
  if (resolvedFilename) {
  return resolvedFilename;

packages/sucrase/test/fixtures/typescript-with-aliases/main.js

@@ -1,4 +1,4 @@
 /* eslint-disable import/extensions, import/no-unresolved */
-import example from '~src/index.ts';
+import example from '~src';
 
 t.snapshot(example.toString());

packages/sucrase/test/fixtures/typescript-with-tsx/example-c.tsx

@@ -0,0 +1 @@
+export default () => <div id="foo">hello world</div>;

packages/sucrase/test/fixtures/typescript-with-tsx/example-d.js/index.tsx

@@ -0,0 +1 @@
+export default () => <div id="foo">hello world</div>;

packages/sucrase/test/fixtures/typescript-with-tsx/example-e.js.tsx

@@ -0,0 +1 @@
+export default () => <div id="foo">hello world</div>;

packages/sucrase/test/fixtures/typescript-with-tsx/main.js

@@ -1,5 +1,12 @@
+/* eslint-disable import/extensions */
 import dirImport from './example-a';
 import fileImport from './example-b';
+import fileImportWithExtension from './example-c.js';
+import dirImportWithExtension from './example-d.js';
+import fileWithDoubleExtension from './example-e.js';
 
 t.snapshot(dirImport.toString());
 t.snapshot(fileImport.toString());
+t.snapshot(fileImportWithExtension.toString());
+t.snapshot(dirImportWithExtension.toString());
+t.snapshot(fileWithDoubleExtension.toString());

packages/sucrase/test/fixtures/typescript/example.ts renamed to packages/sucrase/test/fixtures/typescript/example-a.ts

@@ -0,0 +1 @@
+export default (a: number, b: number): number => a * b;

packages/sucrase/test/fixtures/typescript/example-b.ts

@@ -0,0 +1 @@
+export default (a: number, b: number): number => a * b;

packages/sucrase/test/fixtures/typescript/example-c.js/index.ts

@@ -0,0 +1 @@
+export default (a: number, b: number): number => a * b;