Types
Edit this page on GitHub@sveltejs/kitpermalink
The following types can be imported from @sveltejs/kit
:
Adapterpermalink
interface Adapter {
name: string;
adapt(builder: Builder): Promise<void>;
}
Builderpermalink
interface Builder {
log: Logger;
rimraf(dir: string): void;
mkdirp(dir: string): void;
config: ValidatedConfig;
prerendered: Prerendered;
/** * Create entry points that map to individual functions * @param fn A function that groups a set of routes into an entry point */ createEntries(
fn: (route: RouteDefinition) => AdapterEntry
): void;
generateManifest: (opts: {
relativePath: string;
format?: 'esm' | 'cjs';
}) => string;
getBuildDirectory(name: string): string;
getClientDirectory(): string;
getServerDirectory(): string;
getStaticDirectory(): string;
/** * @param dest the destination folder to which files should be copied * @returns an array of paths corresponding to the files that have been created by the copy */ writeClient(dest: string): string[];
/** * * @param dest */ writePrerendered(
dest: string,
opts?: {
fallback?: string;
}
): string[];
/** * @param dest the destination folder to which files should be copied * @returns an array of paths corresponding to the files that have been created by the copy */ writeServer(dest: string): string[];
/** * @param dest the destination folder to which files should be copied * @returns an array of paths corresponding to the files that have been created by the copy */ writeStatic(dest: string): string[];
/** * @param from the source file or folder * @param to the destination file or folder * @param opts.filter a function to determine whether a file or folder should be copied * @param opts.replace a map of strings to replace * @returns an array of paths corresponding to the files that have been created by the copy */ copy(
from: string,
to: string,
opts?: {
filter?: (basename: string) => boolean;
replace?: Record<string, string>;
}
): string[];
}
Configpermalink
interface Config {
compilerOptions?: CompileOptions;
extensions?: string[];
kit?: {
adapter?: Adapter;
amp?: boolean;
appDir?: string;
browser?: {
hydrate?: boolean;
router?: boolean;
};
csp?: {
mode?: 'hash' | 'nonce' | 'auto';
directives?: CspDirectives;
};
endpointExtensions?: string[];
files?: {
assets?: string;
hooks?: string;
lib?: string;
routes?: string;
serviceWorker?: string;
template?: string;
};
floc?: boolean;
inlineStyleThreshold?: number;
methodOverride?: {
parameter?: string;
allowed?: string[];
};
outDir?: string;
package?: {
dir?: string;
emitTypes?: boolean;
exports?(filepath: string): boolean;
files?(filepath: string): boolean;
};
paths?: {
assets?: string;
base?: string;
};
prerender?: {
concurrency?: number;
crawl?: boolean;
default?: boolean;
enabled?: boolean;
entries?: string[];
onError?: PrerenderOnErrorValue;
};
routes?: (filepath: string) => boolean;
serviceWorker?: {
register?: boolean;
files?: (filepath: string) => boolean;
};
trailingSlash?: TrailingSlash;
version?: {
name?: string;
pollInterval?: number;
};
vite?:
| import('vite').UserConfig
| (() => MaybePromise<import('vite').UserConfig>);
};
preprocess?: any;
}
ErrorLoadpermalink
interface ErrorLoad<
Params = Record<string, string>,
Props = Record<string, any>
> {
(input: ErrorLoadInput<Params>): MaybePromise<
LoadOutput<Props>
>;
}
ExternalFetchpermalink
interface ExternalFetch {
(req: Request): Promise<Response>;
}
GetSessionpermalink
interface GetSession {
(event: RequestEvent): MaybePromise<App.Session>;
}
Handlepermalink
interface Handle {
(input: {
event: RequestEvent;
resolve(
event: RequestEvent,
opts?: ResolveOptions
): MaybePromise<Response>;
}): MaybePromise<Response>;
}
HandleErrorpermalink
interface HandleError {
(input: {
error: Error & { frame?: string };
event: RequestEvent;
}): void;
}
Loadpermalink
The type of a load
function exported from <script context="module">
in a page or layout.
Note that you can use generated types instead of manually specifying the Params generic argument.
interface Load<
Params extends Record<string, string> = Record<
string,
string
>,
InputProps extends Record<string, any> = Record<
string,
any
>,
OutputProps extends Record<string, any> = InputProps
> {
(input: LoadInput<Params, InputProps>): MaybePromise<
Either<Fallthrough, LoadOutput<OutputProps>>
>;
}
Navigationpermalink
interface Navigation {
from: URL;
to: URL;
}
Pagepermalink
interface Page<
Params extends Record<string, string> = Record<
string,
string
>
> {
url: URL;
params: Params;
stuff: App.Stuff;
status: number;
error: Error | null;
}
RequestHandlerpermalink
A function exported from an endpoint that corresponds to an
HTTP verb (get
, put
, patch
, etc) and handles requests with
that method. Note that since 'delete' is a reserved word in
JavaScript, delete handles are called del
instead.
Note that you can use generated types
instead of manually specifying the Params
generic argument.
interface RequestHandler<
Params = Record<string, string>,
Output extends Body = Body
> {
(
event: RequestEvent<Params>
): RequestHandlerOutput<Output>;
}
RequestHandlerOutputpermalink
type RequestHandlerOutput<Output extends Body = Body> =
MaybePromise<
Either<
{
status?: number;
headers?: Headers | Partial<ResponseHeaders>;
body?: Output;
},
Fallthrough
>
>;
SSRManifestpermalink
interface SSRManifest {
appDir: string;
assets: Set<string>;
/** private fields */ _: {
mime: Record<string, string>;
entry: {
file: string;
js: string[];
css: string[];
};
nodes: SSRNodeLoader[];
routes: SSRRoute[];
};
}
Serverpermalink
class Server {
constructor(manifest: SSRManifest);
respond(
request: Request,
options?: RequestOptions
): Promise<Response>;
}
Additional typespermalink
The following are referenced by the public types documented above, but cannot be imported directly:
AdapterEntrypermalink
interface AdapterEntry {
/** * A string that uniquely identifies an HTTP service (e.g. serverless function) and is used for deduplication. * For example, `/foo/a-[b]` and `/foo/[c]` are different routes, but would both * be represented in a Netlify _redirects file as `/foo/:param`, so they share an ID */ id: string;
/** * A function that compares the candidate route with the current route to determine * if it should be treated as a fallback for the current route. For example, `/foo/[c]` * is a fallback for `/foo/a-[b]`, and `/[...catchall]` is a fallback for all routes */ filter: (route: RouteDefinition) => boolean;
/** * A function that is invoked once the entry has been created. This is where you * should write the function to the filesystem and generate redirect manifests. */ complete: (entry: {
generateManifest: (opts: {
relativePath: string;
format?: 'esm' | 'cjs';
}) => string;
}) => void;
}
Bodypermalink
type Body =
| JSONValue
| Uint8Array
| ReadableStream
| import('stream').Readable;
Csppermalink
namespace Csp {
type ActionSource = 'strict-dynamic' | 'report-sample';
type BaseSource =
| 'self'
| 'unsafe-eval'
| 'unsafe-hashes'
| 'unsafe-inline'
| 'none';
type CryptoSource = `${
| 'nonce'
| 'sha256'
| 'sha384'
| 'sha512'}-${string}`;
type FrameSource =
| HostSource
| SchemeSource
| 'self'
| 'none';
type HostNameScheme = `${string}.${string}` | 'localhost';
type HostSource =
`${HostProtocolSchemes}${HostNameScheme}${PortScheme}`;
type HostProtocolSchemes = `${string}://` | '';
type HttpDelineator = '/' | '?' | '#' | '\\';
type PortScheme = `:${number}` | '' | ':*';
type SchemeSource =
| 'http:'
| 'https:'
| 'data:'
| 'mediastream:'
| 'blob:'
| 'filesystem:';
type Source =
| HostSource
| SchemeSource
| CryptoSource
| BaseSource;
type Sources = Source[];
type UriPath = `${HttpDelineator}${string}`;
}
CspDirectivespermalink
interface CspDirectives {
'child-src'?: Csp.Sources;
'default-src'?: Array<Csp.Source | Csp.ActionSource>;
'frame-src'?: Csp.Sources;
'worker-src'?: Csp.Sources;
'connect-src'?: Csp.Sources;
'font-src'?: Csp.Sources;
'img-src'?: Csp.Sources;
'manifest-src'?: Csp.Sources;
'media-src'?: Csp.Sources;
'object-src'?: Csp.Sources;
'prefetch-src'?: Csp.Sources;
'script-src'?: Array<Csp.Source | Csp.ActionSource>;
'script-src-elem'?: Csp.Sources;
'script-src-attr'?: Csp.Sources;
'style-src'?: Array<Csp.Source | Csp.ActionSource>;
'style-src-elem'?: Csp.Sources;
'style-src-attr'?: Csp.Sources;
'base-uri'?: Array<Csp.Source | Csp.ActionSource>;
sandbox?: Array<
| 'allow-downloads-without-user-activation'
| 'allow-forms'
| 'allow-modals'
| 'allow-orientation-lock'
| 'allow-pointer-lock'
| 'allow-popups'
| 'allow-popups-to-escape-sandbox'
| 'allow-presentation'
| 'allow-same-origin'
| 'allow-scripts'
| 'allow-storage-access-by-user-activation'
| 'allow-top-navigation'
| 'allow-top-navigation-by-user-activation'
>;
'form-action'?: Array<Csp.Source | Csp.ActionSource>;
'frame-ancestors'?: Array<
Csp.HostSource | Csp.SchemeSource | Csp.FrameSource
>;
'navigate-to'?: Array<Csp.Source | Csp.ActionSource>;
'report-uri'?: Csp.UriPath[];
'report-to'?: string[];
'require-trusted-types-for'?: Array<'script'>;
'trusted-types'?: Array<
'none' | 'allow-duplicates' | '*' | string
>;
'upgrade-insecure-requests'?: boolean;
/** @deprecated */ 'require-sri-for'?: Array<
'script' | 'style' | 'script style'
>;
/** @deprecated */ 'block-all-mixed-content'?: boolean;
/** @deprecated */ 'plugin-types'?: Array<`${string}/${string}` | 'none'>;
/** @deprecated */ referrer?: Array<
| 'no-referrer'
| 'no-referrer-when-downgrade'
| 'origin'
| 'origin-when-cross-origin'
| 'same-origin'
| 'strict-origin'
| 'strict-origin-when-cross-origin'
| 'unsafe-url'
| 'none'
>;
}
Eitherpermalink
ErrorLoadInputpermalink
interface ErrorLoadInput<Params = Record<string, string>>
extends LoadInput<Params> {
status?: number;
error?: Error;
}
Fallthroughpermalink
interface Fallthrough {
fallthrough: true;
}
HttpMethodpermalink
type HttpMethod =
| 'get'
| 'head'
| 'post'
| 'put'
| 'delete'
| 'patch';
JSONObjectpermalink
interface JSONObject {
[key: string]: JSONValue;
}
JSONValuepermalink
type JSONValue =
| string
| number
| boolean
| null
| undefined
| ToJSON
| JSONValue[]
| JSONObject;
LoadInputpermalink
interface LoadInput<
Params = Record<string, string>,
Props = Record<string, any>
> {
url: URL;
params: Params;
props: Props;
fetch(
info: RequestInfo,
init?: RequestInit
): Promise<Response>;
session: App.Session;
stuff: Partial<App.Stuff>;
}
LoadOutputpermalink
interface LoadOutput<Props = Record<string, any>> {
status?: number;
error?: string | Error;
redirect?: string;
props?: Props;
stuff?: Partial<App.Stuff>;
maxage?: number;
}
Loggerpermalink
interface Logger {
(msg: string): void;
success(msg: string): void;
error(msg: string): void;
warn(msg: string): void;
minor(msg: string): void;
info(msg: string): void;
}
MaybePromisepermalink
type MaybePromise<T> = T | Promise<T>;
Onlypermalink
type Only<T, U> = { [P in keyof T]: T[P] } & {
[P in Exclude<keyof U, keyof T>]?: never;
};
PrerenderErrorHandlerpermalink
interface PrerenderErrorHandler {
(details: {
status: number;
path: string;
referrer: string | null;
referenceType: 'linked' | 'fetched';
}): void;
}
PrerenderOnErrorValuepermalink
type PrerenderOnErrorValue =
| 'fail'
| 'continue'
| PrerenderErrorHandler;
Prerenderedpermalink
interface Prerendered {
pages: Map<
string,
{
/** The location of the .html file relative to the output directory */ file: string;
}
>;
assets: Map<
string,
{
/** The MIME type of the asset */ type: string;
}
>;
redirects: Map<
string,
{
status: number;
location: string;
}
>;
/** An array of prerendered paths (without trailing slashes, regardless of the trailingSlash config) */ paths: string[];
}
RequestEventpermalink
interface RequestEvent<Params = Record<string, string>> {
request: Request;
url: URL;
params: Params;
locals: App.Locals;
platform: Readonly<App.Platform>;
}
RequestOptionspermalink
interface RequestOptions {
platform?: App.Platform;
}
ResolveOptionspermalink
interface ResolveOptions {
ssr?: boolean;
transformPage?: ({
html
}: {
html: string;
}) => MaybePromise<string>;
}
ResponseHeaderspermalink
string[]
is only for set-cookie, everything else must be type of string
type ResponseHeaders = Record<
string,
string | number | string[]
>;
RouteDefinitionpermalink
interface RouteDefinition {
type: 'page' | 'endpoint';
pattern: RegExp;
segments: RouteSegment[];
methods: HttpMethod[];
}
RouteSegmentpermalink
interface RouteSegment {
content: string;
dynamic: boolean;
rest: boolean;
}
ToJSONpermalink
interface ToJSON {
toJSON(...args: any[]): Exclude<JSONValue, ToJSON>;
}
TrailingSlashpermalink
type TrailingSlash = 'never' | 'always' | 'ignore';
Apppermalink
It's possible to tell SvelteKit how to type objects inside your app by declaring the App
namespace. By default, a new project will have a file called src/app.d.ts
containing the following:
/// <reference types="@sveltejs/kit" />
declare namespace App {
interface Locals {}
interface Platform {}
interface Session {}
interface Stuff {}
}
By populating these interfaces, you will gain type safety when using event.locals
, event.platform
, session
and stuff
:
Localspermalink
The interface that defines event.locals
, which can be accessed in hooks (handle
, handleError
and getSession
) and endpoints.
interface Locals {}
Platformpermalink
If your adapter provides platform-specific context via event.platform
, you can specify it here.
interface Platform {}
Sessionpermalink
The interface that defines session
, both as an argument to load
functions and the value of the session store.
interface Session {}
Stuffpermalink
The interface that defines stuff
, as input or output to load
or as the value of the stuff
property of the page store.
interface Stuff {}
Generated typespermalink
The RequestHandler
and Load
types both accept a Params
argument allowing you to type the params
object. For example this endpoint expects foo
, bar
and baz
params:
src/routes/[foo]/[bar]/[baz].js
ts
* foo: string;* bar: string;* baz: string* }>} */export async functionA function whose declared type is neither 'void' nor 'any' must return a value.2355A function whose declared type is neither 'void' nor 'any' must return a value.({ get params }) {// ...}
Needless to say, this is cumbersome to write out, and less portable (if you were to rename the [foo]
directory to [qux]
, the type would no longer reflect reality).
To solve this problem, SvelteKit generates .d.ts
files for each of your endpoints and pages:
.svelte-kit/types/src/routes/[foo]/[bar]/[baz].d.ts
import type { RequestHandler as GenericRequestHandler, Load as GenericLoad } from '@sveltejs/kit';
export type RequestHandler<Body = any> = GenericRequestHandler<
{ foo: string; bar: string; baz: string },
Body
>;
export type Load<Props = Record<string, any>> = GenericLoad<
{ foo: string; bar: string; baz: string },
Props
>;
These files can be imported into your endpoints and pages as siblings, thanks to the rootDirs
option in your TypeScript configuration:
src/routes/[foo]/[bar]/[baz].js
ts
export async functionget ({params }) {// ...}
<script context="module">
/** @type {import('./[baz]').Load} */ export async function load({ params, fetch, session, stuff }) {
// ... }
</script>
For this to work, your own
tsconfig.json
orjsconfig.json
should extend from the generated.svelte-kit/tsconfig.json
(where.svelte-kit
is youroutDir
):{ "extends": "./.svelte-kit/tsconfig.json" }