Suspecious about same values check in Typescript

[sadiki-o]

🔎 Search Terms

Typescript checking same parameters
Dynamic vs Static typing Typescript

🕗 Version & Regression Information

Property 'group' does not exist on type 'string | { type: "group"; columnIndex: number; group: (string | { type: "operation"; columnType: Primitive; value: string[]; })[]; }'.
Property 'group' does not exist on type 'string'.

⏯ Playground Link

https://www.typescriptlang.org/play?#code/C4TwDgpgBACgTgSwLYOAgbtAvFA5AOwFckAjCOXKAHzwGdhF8BzSm3Egew4BsIBDfLgDcAKBGhIUAMrIwvAIqFyIACrhsUABQiou6lHqMmOvTQDeJvXokQAXHiZwOhMMMtWoAYx7F8ASXwAEwgAD3siUnJRDz1HZzB7bRiYmkMEZndk-QssrJt7XA5IOD40DkFo3Jjvbl81SHt4ZFQMCEqqq3Q+WrsDBnSmAG0AXXbcgF9MvQBKEbHJ2dGxb3x6KABHJTgQexkkOQhFZXqNEbERFbWXQNKIADVupSgsd010ezTmABooCE3uj79b5QdLBMJQQYRMhwH5Q8jDab2AQgZ4APigFimugQADMtFiPDYOHjNspBqDQoMAAzDYZQACEWBwuE+LCgADJ2QSrKTtuSgpSacMAHRxFz8sGDACMtIJ0wx3L0cAgwEIcHwUAAtFKxlZJnrluUrmAbsB7o8IAB9Z6vd59Iw-P6EAH2gY-CngyHEaGw73wxFQZFohVZXH4jpQIkkrYgQbUn4y6m0hlMuhAtmcxW6Xmx+NQRNC0VOcUe6WyrLynIdZWq9VanUE-V6SYXI3AKDXW4PHqW60vKxvQEO37-bhDt0ggWeuEwqAzhFI-AorDoqvVNsGPhIc1jud+uDPKAAOX3mip011ejDSQ6UY2McGtC3O7pjOZrMomYjOcfz+7IrFMAJUpGVhjlENqxVNUNW1S9dCbeDDVWdtOzNbslF7PtbXHYEnRdVl3SnewvUiWd5wDIMVwg9dkM3bdu3CfdDxPUjNFLGkLwJa8s0jdRiXvMkn3o7pX1TFl00-LlvwfISXyLeJgJCMswIrajchraD6zgqAEJ0pDjVNHcMMwm0BztAiR2dXcLI9YiZ19UiF0DJdg0xUM8RvKo7x-GkU3fCSOSkjofIA4sgNLUDwLXdSoLrWDG3ccYgA

💻 Code

type Primitive = 'number' | 'string' | 'boolean';

type SimpleQueryType = (
    | string
    | {
        type: 'group';
        columnIndex: number;
        group: (
            | string
            | {
                type: 'operation';
                columnType: Primitive;
                value: string[];
            }
        )[];
    }
)[];

const query: SimpleQueryType = []


const updateValue =
    (v: string, equal: string, index: [number, number]): any => {

        if (
            typeof query[index[0]] !== 'string' &&
            query[index[0]].group[index[1]]
        ) {
            return -1;
        }
    }

const updateValue_ =
    (v: string, equal: string, index: [number, number]): any => {
        if (
            typeof query[[0, 1][0]] !== 'string' &&
            query[[0, 1][0]].group[index[1]]
        ) {
            return -1;
        }
    }

const updateValue__ =
    (v: string, equal: string, index: [number, number]): any => {
        const sameVal: number = Number(0);
        if (
            typeof query[sameVal] !== 'string' &&
            query[sameVal].group[index[1]]
        ) {
            return -1;
        }
    }

const updateValue___ =
    (v: string, equal: string, index: [number, number]): any => {
        const sameVal: number = Number(index[0]);
        if (
            typeof query[sameVal] !== 'string' &&
            query[sameVal].group[index[1]]
        ) {
            return -1;
        }
    }

🙁 Actual behavior

This code is weird because passing the same values as array index , Typescript consider them to be different (I understand how arrays are passed by reference so the array could get modified by the same the first check and the second check use that index). The only way Typescript consider those two values the same is when you pass static values . Passing Number(0) also doesn't work !!

🙂 Expected behavior

It should consider passing the same variable at least (instead of array values) make the check pass:

const updateValue___ =
    (v: string, equal: string, index: [number, number]): any => {

        if (
            typeof query[0] !== 'string' &&
            query[0].group[index[1]]
        ) {
            return -1;
        }
    }

Additional information about the issue

I may be wrong on how Typescript handle such cases so sorry in advance if i mis-understand things

[MartinJohns]

Duplicate of #56389.

[typescript-bot]

This issue has been marked as "Duplicate" and has seen no recent activity. It has been automatically closed for house-keeping purposes.