JS: property on function "used before being assigned" regression

[brendankenny]

TypeScript Version: master, due to #27128

Search Terms:
is used before being assigned, property on function, expando

Code

// test.js
class TestClass {}
TestClass.NONE = 'NONE';

function fn() {
  console.log(TestClass.NONE); // error TS2565: Property 'NONE' is used before being assigned.
}

test with tsc --strict --allowJs --checkJs --noEmit

Expected behavior:
No error.

Error only seems to appear if the property is accessed within another function body, not top-level (or same level). Not an error without --strictNullChecks.

Testing with latest found this error when a property was defined on a function or class (outside its body) and then required from a different file, but it appears to be the same problem if they're in the same file, as in the example above.

[brendankenny]

🎉🎉 thanks for the fast fix!

[sandersn]

Yep, 3.1 is due out pretty soon! 😅