export declare const DEFAULT_NPM_REGISTRY = "https://registry.npmjs.org";
export type NpmConfigOrigin = "env" | "user" | "global";
/** Which package manager will run the install this check is gating. */
export type Installer = "bun" | "npm";
/** Injection points so tests never read the real environment. */
export interface NpmRegistryEnvironment {
    /** Manager that will perform the install; decides Bun-vs-npm config priority. */
    installer?: Installer;
    /** Resolves an executable on PATH; used to locate npm's effective prefix. */
    whichExecutable?: (name: string) => string | undefined;
    /** Defaults to `$credentialEnv`, which excludes the caller's `cwd/.env`. */
    lookupEnv?: (name: string) => string | undefined;
    homeDir?: string;
    platform?: NodeJS.Platform;
    readFile?: (filePath: string) => Promise<string | undefined>;
}
export interface ResolvedNpmRegistry {
    registry: string;
    headers: Record<string, string>;
    origin: NpmConfigOrigin | "default";
    /** Where the value came from, e.g. `$npm_config_registry` or `~/.npmrc`. */
    source: string;
    /** Config files that exist but could not be read. */
    warnings: string[];
}
export interface LatestPackageVersion {
    version: string;
    registry: string;
    /** Config problems that did not stop the lookup but changed its outcome. */
    warnings: string[];
}
export interface FetchResponseLike {
    ok: boolean;
    status: number;
    statusText: string;
    json: () => Promise<unknown>;
}
export type FetchLike = (input: string, init?: {
    headers?: Record<string, string>;
    signal?: AbortSignal;
}) => Promise<FetchResponseLike>;
export interface NpmRegistryLookupOptions extends NpmRegistryEnvironment {
    fetchImpl?: FetchLike;
    timeoutMs?: number;
    /** npm dist-tag to resolve; defaults to `latest`. Nightly channel lookups pass `nightly`. */
    distTag?: string;
}
/** Thrown when a registry is configured but unusable, so it is never silently ignored. */
export declare class NpmRegistryConfigError extends Error {
}
/**
 * Parse an `.npmrc` into raw key/value pairs. Later duplicates win, as in npm.
 *
 * @internal Exported for tests; production code goes through `resolveNpmRegistry`.
 */
export declare function parseNpmrc(contents: string, lookupEnv?: (name: string) => string | undefined): Map<string, string>;
/**
 * Build the credential lookup keys npm calls "nerf darts": `//host/path/`,
 * walking up one path segment at a time until the bare host.
 *
 * @internal Exported for tests; production code goes through `resolveNpmRegistry`.
 */
export declare function credentialPrefixes(registry: string): string[];
/** Resolve the registry npm/bun would use for `packageName`, with credentials attached. */
export declare function resolveNpmRegistry(packageName: string, environment?: NpmRegistryEnvironment): Promise<ResolvedNpmRegistry>;
/**
 * Registries can live under a path prefix, so join by string rather than `new URL`.
 *
 * @internal Exported for tests; production code goes through `fetchLatestPackageVersion`.
 */
export declare function buildRegistryPackageUrl(registry: string, packageName: string, spec?: string): string;
/** Fetch the published version of `packageName` at `options.distTag` (default `latest`) from the configured registry. */
export declare function fetchLatestPackageVersion(packageName: string, options?: NpmRegistryLookupOptions): Promise<LatestPackageVersion>;