Tuple Restriction Issue: Inconsistent Behavior with Array Methods

[srosama]

🔎 Search Terms

In TypeScript, tuples are expected to have a fixed length and type for each element. However, using array methods like push allows additional elements to be added, which violates the tuple's intended constraints.

💻 Code

let user: [number, string] = [1, "Ahmed"];

// Adding elements beyond the defined tuple length
user.push(2);
user.push(3);

🙁 Actual behavior

The current behavior allows additional elements to be pushed into the tuple without any compile-time errors, leading to a runtime output of:
1
Ahmed
2
3

🙂 Expected behavior

The TypeScript compiler should raise an error when attempting to add elements beyond the fixed length of the tuple. For example:
let user: [number, string] = [1, "Ahmed"];
user.push(2); // Should raise a compile-time error
user.push(3); // Should raise a compile-time error

Additional information about the issue

Suggestions

Compile-Time Checks: Introduce stricter compile-time checks for tuple operations to prevent methods like push, pop, shift, and unshift from modifying the tuple length.
Utility Types: Provide utility types or methods to safely handle tuple operations without violating their constraints.
Documentation: Enhance the documentation to clarify the behavior of tuples and the limitations of using array methods on them.

[MartinJohns]

Duplicate of #40316.

[typescript-bot]

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