fix(stylelint): only lint when file can be parsed by babel (reduces n…

…oisey errors as developer types) (#1076)

* avoid constant erroring while developer types

* remove console.log

* add changeset

Co-authored-by: Tim Kutnick <tim.kutnick@airbnb.com>

.changeset/cold-swans-unite.md

@@ -0,0 +1,5 @@
+---
+'@linaria/postcss-linaria': patch
+---
+
+Only lint when file can be parsed by babel, reduce noisey errors during dev

packages/postcss-linaria/__tests__/parse.test.ts

@@ -382,4 +382,11 @@ describe('parse', () => {
       expect(ast.source!.input.css).toEqual(source);
     });
   });
+
+  it('should return empty document if babel cannot parse file', () => {
+    const { ast } = createTestAst(`this is not valid source code for a file`);
+    expect(ast.type).toEqual('document');
+    expect(ast.raws).toEqual({});
+    expect(ast.nodes.length).toEqual(0);
+  });
 });

packages/postcss-linaria/src/parse.ts

@@ -107,11 +107,19 @@ export const parse: Parser<Root | Document> = (
 ): Root | Document => {
   const doc = new Document();
   const sourceAsString = source.toString();
-  const ast = babelParse(sourceAsString, {
-    sourceType: 'unambiguous',
-    plugins: ['typescript', 'jsx'],
-    ranges: true,
-  });
+
+  // avoid error spam (and vscode error toasts) if babel can't parse doc
+  // allows user to type new code without constant warnings
+  let ast;
+  try {
+    ast = babelParse(sourceAsString, {
+      sourceType: 'unambiguous',
+      plugins: ['typescript', 'jsx'],
+      ranges: true,
+    });
+  } catch {
+    return doc;
+  }
   const extractedStyles = new Set<TaggedTemplateExpression>();
 
   traverse(ast, {