[General] [Fixed] - Fix URLSearchParams.keys() returning only unique keys

[Nedunchezhiyan-M]

Summary:

The URLSearchParams.keys() method was returning Map.keys() directly, which yields each unique key only once. The WHATWG URL spec requires keys() to return an iterator that yields one entry per name-value pair, meaning duplicate names must appear multiple times.

For example, given new URLSearchParams('a=1&a=2&b=3'):

• Before: [...params.keys()] returns ['a', 'b'] (unique keys only)
• After: [...params.keys()] returns ['a', 'a', 'b'] (one per pair, as specified)

This made keys() inconsistent with values() and entries(), both of which already handle duplicates correctly using generator functions. The fix applies the same generator pattern to keys().

Changelog:

[General] [Fixed] - Fix URLSearchParams.keys() returning only unique keys instead of all name-value pair names

Test Plan:

Added a test asserting that keys() on a URLSearchParams instance with duplicate key entries yields all names including duplicates:

const paramsFromArray = new URLSearchParams([
  ['key1', 'value1'],
  ['key1', 'value2'],
  ['key2', 'value3'],
]);
const keysArray = Array.from(paramsFromArray.keys());
expect(keysArray).toEqual(['key1', 'key1', 'key2']);

Verification: The fix is consistent with browser behaviour:

// In browser console (Chrome/Firefox/Safari):
[...new URLSearchParams('a=1&a=2&b=3').keys()] // ['a', 'a', 'b']

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