TypeScript Compiler API: create a type node from a string

create-type-node-from-string.ts

import assert from "assert";
import ts, { isTypeAliasDeclaration } from "typescript";

function createTypeNodeFromString(type: string): ts.TypeNode {
  const sourceFile = ts.createSourceFile("source.ts", `type A = ${type};`, ts.ScriptTarget.Latest);
  const statement = sourceFile.statements[0];
  assert(isTypeAliasDeclaration(statement));
  return statement.type;
}