ts__default$1.default.isTypeAssertionExpression is not a function (ts)

[mejgun]

Describe the bug
after update to 1.1.15 svelte-check returns error on each svelte component

<component>.svelte:NaN:1
Error: ts__default$1.default.isTypeAssertionExpression is not a function (ts)

project builds and works ok, vscode shows no error

To Reproduce
npm upgrade && npx svelte-check

System (please complete the following information):

• OS: Linux
• IDE: VSCode
• Plugin/Package: svelte+TS

Additional context

  "devDependencies": {
    "@rollup/plugin-commonjs": "^14.0.0",
    "@rollup/plugin-node-resolve": "^8.0.0",
    "@rollup/plugin-typescript": "^6.1.0",
    "@tsconfig/svelte": "^1.0.0",
    "rollup": "^2.33.3",
    "rollup-plugin-livereload": "^2.0.0",
    "rollup-plugin-svelte": "^6.1.1",
    "rollup-plugin-terser": "^7.0.0",
    "svelte": "^3.29.7",
    "svelte-check": "^1.1.15",
    "svelte-preprocess": "^4.6.1",
    "tslib": "^2.0.3",
    "typescript": "^3.9.7"
  }

[dummdidumm]

Try upgrading TypeScript to the latest version. It seems like the isTypeAssertionExpression function got added only recently to TypeScript, which we are using inside svelte2tsx.

@jasonlyu123 should we maybe fall back to using a "handcrafted" version of that function? As an alternative we can also just check for the existence of this function. It will "only" prevent people from getting the <any>foo to foo as any transformation. I think I'm slightly in favor of the latter solution. Edit: I chose the latter solution for a simple fix. If you think that's crap we can switch to the handcrafted function.

[mejgun]

Try upgrading TypeScript to the latest version. It seems like the isTypeAssertionExpression function got added only recently to TypeScript, which we are using inside svelte2tsx.

Thanks. Problem solved :-)