fix: restore full destructure bindings and silence ESLint unused-var warnings

[precondition]

Overview

This pull request fixes a critical bug in convert_keymap_extras_header.js that caused it to fail on all inputs. It restores the full destructure bindings and adds // eslint-disable-next-line no-unused-vars directives to preserve positional correctness while avoiding linting errors.

Description

Commit 0828211 introduced a regression in the convert_keymap_extras_header.js script used for i18n keymap extras.

Several destructuring assignments (let [a, b, c] = function_call();) had commented-out elements (e.g. /*fullMatch, */) to avoid no-unused-vars warnings.

/home/username/Coding/qmk/configurator/src/i18n/keymap_extras/convert_keymap_extras_header.js
  126:12  error  'fullMatch' is assigned a value but never used  no-unused-vars
  241:10  error  'fullMatch' is assigned a value but never used  no-unused-vars
  256:21  error  'intlAlias' is assigned a value but never used  no-unused-vars
  256:48  error  'comment' is assigned a value but never used    no-unused-vars
  336:8   error  'fullMatch' is assigned a value but never used  no-unused-vars

It appears that these unused variables (which are indeed unused because only a subset of the destructured outputs of a function are used) were quickly commented out to get rid of the warning. Unfortunately, this broke the code because the variables were no longer assigned to the correct output of the function within the destructuring assignments (if you turn let [a, b, c] = function_call(); into let [a, /*b,*/ c] = function_call();, variable c will point to what was intended to be b).

There are multiple ways to deal with this problem:

Option 1: eslint disable comment

// eslint-disable-next-line no-unused-vars
const [fullMatch, intlAlias, macroExpansion] = kcAliasDefRegExp.exec(line);

(does not make it clear which variable exactly is unused)

Option 2: Ignore variables with an underscore prefix

Add a rule in eslint.config.js to ignore the no-unused-vars warning for variables that start with an underscore:

"rules": {
  "no-unused-vars": ["error", { "argsIgnorePattern": "^_", "varsIgnorePattern": "^_" }]
}

and then do this in the code:

const [_fullMatch, intlAlias, macroExpansion] = kcAliasDefRegExp.exec(line);

(makes it clear which variable exactly is unused)

Option 3: name all unused variables as _

Unfortunately, this option will not work. Consider the case of multiple ignored/unused variables in the destructured assignment of line 256 in function convertLine:

256    let [fullMatch, _, macroExpansion, _] = kcAliasDefRegExp.exec(line);

/home/username/Coding/qmk/configurator/src/i18n/keymap_extras/convert_keymap_extras_header.js
  256:40  error  Parsing error: Identifier '_' has already been declared

---

For now, the PR adopts option 1 but this can be discussed.

Affected functions

• computeIntl2US
• convertLine
• generateSpaceCadetKcInfo

Relevant discussion thread on Discord: https://discord.com/channels/440868230475677696/867530744116543508/1434968023113928848

[yanfali]

ah ok. I see the issue you're running into. You're de-structuring into an array. since you really don't care about those have you tried this?

const [first, , third] = array;  // Skip second element
const [, , third] = array;       // Skip first two

[precondition]

ah ok. I see the issue you're running into. You're de-structuring into an array. since you really don't care about those have you tried this?

const [first, , third] = array;  // Skip second element
const [, , third] = array;       // Skip first two

I did not know about this feature of the JavaScript syntax. Implemented in commit e4efd78.

[yanfali]

Lgtm

[yanfali]

oh sorry. I forgot you can't merge.