functions params: select prompt ignores a non-string default and preselects the first option

[CorieW]

[REQUIRED] Environment info

firebase-tools: 15.26.0 (code is unchanged on main at ecda4df)

Platform: Windows (not platform specific)

[REQUIRED] Test case

A non-string param with a select input whose default is not the first option:

import { defineBoolean, select } from "firebase-functions/params";

export const makePublic = defineBoolean("MAKE_PUBLIC", {
  label: "Make resized images public",
  default: false,
  input: select({ Yes: true, No: false }),
});

[REQUIRED] Steps to reproduce

1. Declare the param above in a functions codebase.
2. Run firebase deploy --only functions with MAKE_PUBLIC unset so the CLI prompts for it.
3. Observe which option is highlighted, then press Enter.

[REQUIRED] Expected behavior

"No" is preselected, since the declared default is false. Pressing Enter stores MAKE_PUBLIC=false.

[REQUIRED] Actual behavior

"Yes" (the first option) is preselected. Pressing Enter stores MAKE_PUBLIC=true.

Cause: promptSelect passes the resolved default to inquirer unchanged but stringifies every option value, so a boolean or number default never matches a choice and inquirer falls back to the first one.

firebase-tools/src/deploy/functions/params.ts

Lines 914 to 928 in ecda4df

	async function promptSelect<T extends RawParamValue>(
	prompt: string,
	input: SelectInput<T>,
	resolvedDefault: T | undefined,
	converter: (res: string) => T | retryInput,
	): Promise<T> {
	const response = await select<string>({
	default: resolvedDefault as string,
	message: prompt,
	choices: input.select.options.map((option: SelectOptions<T>): ListItem => {
	return {
	checked: false,
	name: option.label,
	value: option.value.toString(),
	};

const response = await select<string>({
  default: resolvedDefault as string,
  ...
  choices: input.select.options.map((option) => ({
    value: option.value.toString(),

Affects defineBoolean and defineInt selects; string selects are fine. Any param whose default is the first option looks correct by coincidence, which is why this is easy to miss.

Suggested fix: default: resolvedDefault?.toString() (or compare against option.value before stringifying). promptSelectMultiple (L953) has the same pattern for defineList defaults.

Found while migrating the storage-resize-images extension to a Function Kit: firebase/extensions#3148 works around it by declaring the param as a string.