fix(functions): preselect list param defaults in multi-select prompts

[Ishkirat-Singh]

Description

promptSelectMultiple passed the resolved default to the checkbox prompt as default, but @inquirer/checkbox has no such option — it preselects through checked on each choice, and every choice was hardcoded to checked: false. A defineList param with a multi-select input therefore always opened with nothing selected, whatever default it declared.

This marks the choices whose value is in the resolved default as checked. default is kept because the non-interactive path (guard) still returns it.

Found while fixing #11053 in the same file; there is no separate issue for this one.

Scenarios Tested

• Added preselects the default values in a multi-select prompt to src/deploy/functions/params.spec.ts: a list param with options a/b/c and default ["b", "c"] produces choices checked [false, true, true] and resolves to the expected ParamValue.
• npx mocha src/deploy/functions/params.spec.ts: 19 passing; the new test fails against main without the fix.

Sample Commands

N/A — the change is in the interactive firebase deploy --only functions param prompt.

[gemini-code-assist]

Code Review

This pull request implements preselection of default values for list function parameters in multi-select prompts. It updates promptSelectMultiple to check if each option's value is included in the resolved defaults, adds a corresponding unit test, and updates the changelog. The reviewer suggested a more robust approach to preselection by stringifying the elements of resolvedDefault outside the loop to prevent potential runtime type mismatches and avoid recreating the mapped array on every iteration.

[gemini-code-assist]

To make the preselection more robust against potential runtime type mismatches (e.g., if default values are parsed as numbers or booleans from environment files or configuration), we should stringify the elements of resolvedDefault before performing the .includes() check. Pre-mapping the defaults outside the loop also avoids recreating the mapped array on every iteration.

  const stringifiedDefaults = resolvedDefault?.map((val) => String(val));
  const response = await checkbox({
    // default only serves non-interactive mode; the checkbox prompt itself
    // preselects through checked on each choice.
    default: resolvedDefault,
    message: prompt,
    choices: input.multiSelect.options.map((option: SelectOptions<string>): ListItem => {
      return {
        checked: stringifiedDefaults?.includes(option.value.toString()) ?? false,
        name: option.label,
        value: option.value.toString(),
      };

[Ishkirat-Singh]

Done in 4c59a1a: defaults are stringified once into a Set before the choices are built.