Type 'false' has no call signatures. (tsserver 2349)

I am getting a Typescript warning for the following:

let d: { [key: string]: { [k: string]: boolean } | number[] } = {
  blah: [],
};
d["blah"].push(2);

The warning:

 This expression is not callable.                                               
 Not all constituents of type 'boolean | ((...items: number[]) => number)'    
 are callable.                                                                  
 Type 'false' has no call signatures. (tsserver 2349)  

The code works and if I console.log(d[‘blah’]) I get [2]. Why am I getting the warning? How do I correct it (or ignore it)?

My tsconfig:

{
  "compilerOptions": {
    "target": "es2015",
    "lib": ["dom", "dom.iterable", "esnext"],
    "allowJs": true,
    "skipLibCheck": true,
    "strict": true,
    "noEmit": true,
    "esModuleInterop": true,
    "module": "esnext",
    "moduleResolution": "bundler",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "jsx": "preserve",
    "incremental": true,
    "plugins": [
      {
        "name": "next"
      }
    ],
    "paths": {
      "@/*": ["./*"]
    }
  },
  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
  "exclude": ["node_modules"]
}

I tried printing to the console and the code works so am confused why the warning if it works

>Solution :

According to your typescript interface you defined key can be either an array of number or an object.

So you should first check if d['blah'] is an array then push the value

interface IObjectType {
  [key: string]: {
    [k: string]: boolean
  } | number[]
}


let d: IObjectType = {
  blah: [],
};
if (Array.isArray(d['blah'])) {
  d["blah"].push(2);
}