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@sveltejs/kit/hooks

import { function sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner. The behavior for the handle options is as follows:
 
     
  • transformPageChunk is applied in reverse order and merged
    •  
  • preload is applied in forward order, the first option “wins” and no preload options after it are called
    •  
  • filterSerializedResponseHeaders behaves the same as preload
    •  
 
src/hooks.server
import { sequence } from '@sveltejs/kit/hooks';  /// type: import('@sveltejs/kit').Handle async function first({ event, resolve }) { console.log('first pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { // transforms are applied in reverse order console.log('first transform'); return html; }, preload: () => { // this one wins as it's the first defined in the chain console.log('first preload'); return true; } }); console.log('first post-processing'); return result; }  /// type: import('@sveltejs/kit').Handle async function second({ event, resolve }) { console.log('second pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { console.log('second transform'); return html; }, preload: () => { console.log('second preload'); return true; }, filterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain console.log('second filterSerializedResponseHeaders'); return true; } }); console.log('second post-processing'); return result; }  export const handle = sequence(first, second);
The example above would print:
 
first pre-processing first preload second pre-processing second filterSerializedResponseHeaders second transform first transform second post-processing first post-processing
@paramhandlers The chain of handle functions
sequence } from '@sveltejs/kit/hooks';

sequence

A helper function for sequencing multiple handle calls in a middleware-like manner. The behavior for the handle options is as follows:

  • transformPageChunk is applied in reverse order and merged
  • preload is applied in forward order, the first option “wins” and no preload options after it are called
  • filterSerializedResponseHeaders behaves the same as preload
src/hooks.server
import { function sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner. The behavior for the handle options is as follows:
 
     
  • transformPageChunk is applied in reverse order and merged
    •  
  • preload is applied in forward order, the first option “wins” and no preload options after it are called
    •  
  • filterSerializedResponseHeaders behaves the same as preload
    •  
 
src/hooks.server
import { sequence } from '@sveltejs/kit/hooks';  /// type: import('@sveltejs/kit').Handle async function first({ event, resolve }) { console.log('first pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { // transforms are applied in reverse order console.log('first transform'); return html; }, preload: () => { // this one wins as it's the first defined in the chain console.log('first preload'); return true; } }); console.log('first post-processing'); return result; }  /// type: import('@sveltejs/kit').Handle async function second({ event, resolve }) { console.log('second pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { console.log('second transform'); return html; }, preload: () => { console.log('second preload'); return true; }, filterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain console.log('second filterSerializedResponseHeaders'); return true; } }); console.log('second post-processing'); return result; }  export const handle = sequence(first, second);
The example above would print:
 
first pre-processing first preload second pre-processing second filterSerializedResponseHeaders second transform first transform second post-processing first post-processing
@paramhandlers The chain of handle functions
sequence } from '@sveltejs/kit/hooks';  /** @type {import('@sveltejs/kit').Handle} */ async function 
function first({ event, resolve }: {  event: any;  resolve: any; }): Promise<any>
@type{import('@sveltejs/kit').Handle}
first({ event: anyevent, resolve: anyresolve }) { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first pre-processing'); const const result: anyresult = await resolve: anyresolve(event: anyevent, { 
transformPageChunk: ({ html }: {  html: any; }) => any
transformPageChunk: ({ html: anyhtml }) => { // transforms are applied in reverse order var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first transform'); return html: anyhtml; }, preload: () => booleanpreload: () => { // this one wins as it's the first defined in the chain var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first preload'); return true; } }); var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first post-processing'); return const result: anyresult; }  /** @type {import('@sveltejs/kit').Handle} */ async function 
function second({ event, resolve }: {  event: any;  resolve: any; }): Promise<any>
@type{import('@sveltejs/kit').Handle}
second({ event: anyevent, resolve: anyresolve }) { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second pre-processing'); const const result: anyresult = await resolve: anyresolve(event: anyevent, { 
transformPageChunk: ({ html }: {  html: any; }) => any
transformPageChunk: ({ html: anyhtml }) => { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second transform'); return html: anyhtml; }, preload: () => booleanpreload: () => { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second preload'); return true; }, filterSerializedResponseHeaders: () => booleanfilterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second filterSerializedResponseHeaders'); return true; } }); var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second post-processing'); return const result: anyresult; }  export const const handle: Handlehandle = function sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner. The behavior for the handle options is as follows:
 
     
  • transformPageChunk is applied in reverse order and merged
    •  
  • preload is applied in forward order, the first option “wins” and no preload options after it are called
    •  
  • filterSerializedResponseHeaders behaves the same as preload
    •  
 
src/hooks.server
import { sequence } from '@sveltejs/kit/hooks';  /// type: import('@sveltejs/kit').Handle async function first({ event, resolve }) { console.log('first pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { // transforms are applied in reverse order console.log('first transform'); return html; }, preload: () => { // this one wins as it's the first defined in the chain console.log('first preload'); return true; } }); console.log('first post-processing'); return result; }  /// type: import('@sveltejs/kit').Handle async function second({ event, resolve }) { console.log('second pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { console.log('second transform'); return html; }, preload: () => { console.log('second preload'); return true; }, filterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain console.log('second filterSerializedResponseHeaders'); return true; } }); console.log('second post-processing'); return result; }  export const handle = sequence(first, second);
The example above would print:
 
first pre-processing first preload second pre-processing second filterSerializedResponseHeaders second transform first transform second post-processing first post-processing
@paramhandlers The chain of handle functions
sequence(
function first({ event, resolve }: {  event: any;  resolve: any; }): Promise<any>
@type{import('@sveltejs/kit').Handle}
first, 
function second({ event, resolve }: {  event: any;  resolve: any; }): Promise<any>
@type{import('@sveltejs/kit').Handle}
second);
import { function sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner. The behavior for the handle options is as follows:
 
     
  • transformPageChunk is applied in reverse order and merged
    •  
  • preload is applied in forward order, the first option “wins” and no preload options after it are called
    •  
  • filterSerializedResponseHeaders behaves the same as preload
    •  
 
src/hooks.server
import { sequence } from '@sveltejs/kit/hooks';  /// type: import('@sveltejs/kit').Handle async function first({ event, resolve }) { console.log('first pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { // transforms are applied in reverse order console.log('first transform'); return html; }, preload: () => { // this one wins as it's the first defined in the chain console.log('first preload'); return true; } }); console.log('first post-processing'); return result; }  /// type: import('@sveltejs/kit').Handle async function second({ event, resolve }) { console.log('second pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { console.log('second transform'); return html; }, preload: () => { console.log('second preload'); return true; }, filterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain console.log('second filterSerializedResponseHeaders'); return true; } }); console.log('second post-processing'); return result; }  export const handle = sequence(first, second);
The example above would print:
 
first pre-processing first preload second pre-processing second filterSerializedResponseHeaders second transform first transform second post-processing first post-processing
@paramhandlers The chain of handle functions
sequence } from '@sveltejs/kit/hooks'; import type { 
type Handle = (input: {  event: RequestEvent;  resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>; }) => MaybePromise<...>
The handle hook runs every time the SvelteKit server receives a request and determines the response. It receives an event object representing the request and a function called resolve, which renders the route and generates a Response. This allows you to modify response headers or bodies, or bypass SvelteKit entirely (for implementing routes programmatically, for example).
 
Handle } from '@sveltejs/kit';  const const first: Handlefirst: 
type Handle = (input: {  event: RequestEvent;  resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>; }) => MaybePromise<...>
The handle hook runs every time the SvelteKit server receives a request and determines the response. It receives an event object representing the request and a function called resolve, which renders the route and generates a Response. This allows you to modify response headers or bodies, or bypass SvelteKit entirely (for implementing routes programmatically, for example).
 
Handle = async ({ event: RequestEvent<Record<string, string>, string | null>event, resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>resolve }) => { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first pre-processing'); const const result: Responseresult = await resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>resolve(event: RequestEvent<Record<string, string>, string | null>event, { 
ResolveOptions.transformPageChunk?: ((input: {  html: string;  done: boolean; }) => MaybePromise<string | undefined>) | undefined
Applies custom transforms to HTML. If done is true, it’s the final chunk. Chunks are not guaranteed to be well-formed HTML (they could include an element’s opening tag but not its closing tag, for example) but they will always be split at sensible boundaries such as %sveltekit.head% or layout/page components.
 
@paraminput the html chunk and the info if this is the last chunk
transformPageChunk: ({ html: stringhtml }) => { // transforms are applied in reverse order var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first transform'); return html: stringhtml; }, 
ResolveOptions.preload?: ((input: {  type: "font" | "css" | "js" | "asset";  path: string; }) => boolean) | undefined
Determines what should be added to the &#x3C;head> tag to preload it. By default, js and css files will be preloaded.
 
@paraminput the type of the file and its path
preload: () => { // this one wins as it's the first defined in the chain var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first preload'); return true; } }); var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('first post-processing'); return const result: Responseresult; };  const const second: Handlesecond: 
type Handle = (input: {  event: RequestEvent;  resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>; }) => MaybePromise<...>
The handle hook runs every time the SvelteKit server receives a request and determines the response. It receives an event object representing the request and a function called resolve, which renders the route and generates a Response. This allows you to modify response headers or bodies, or bypass SvelteKit entirely (for implementing routes programmatically, for example).
 
Handle = async ({ event: RequestEvent<Record<string, string>, string | null>event, resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>resolve }) => { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second pre-processing'); const const result: Responseresult = await resolve: (event: RequestEvent, opts?: ResolveOptions) => MaybePromise<Response>resolve(event: RequestEvent<Record<string, string>, string | null>event, { 
ResolveOptions.transformPageChunk?: ((input: {  html: string;  done: boolean; }) => MaybePromise<string | undefined>) | undefined
Applies custom transforms to HTML. If done is true, it’s the final chunk. Chunks are not guaranteed to be well-formed HTML (they could include an element’s opening tag but not its closing tag, for example) but they will always be split at sensible boundaries such as %sveltekit.head% or layout/page components.
 
@paraminput the html chunk and the info if this is the last chunk
transformPageChunk: ({ html: stringhtml }) => { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second transform'); return html: stringhtml; }, 
ResolveOptions.preload?: ((input: {  type: "font" | "css" | "js" | "asset";  path: string; }) => boolean) | undefined
Determines what should be added to the &#x3C;head> tag to preload it. By default, js and css files will be preloaded.
 
@paraminput the type of the file and its path
preload: () => { var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second preload'); return true; }, ResolveOptions.filterSerializedResponseHeaders?: ((name: string, value: string) => boolean) | undefined
Determines which headers should be included in serialized responses when a load function loads a resource with fetch. By default, none will be included.
 
@paramname header name
@paramvalue header value
filterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second filterSerializedResponseHeaders'); return true; } }); var console: Console
The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
 
The module exports two specific components:
 
     
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
    •  
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.
    •  
 
Warning: The global console object’s methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.
 
Example using the global console:
 
console.log('hello world'); // Prints: hello world, to stdout console.log('hello %s', 'world'); // Prints: hello world, to stdout console.error(new Error('Whoops, something bad happened')); // Prints error message and stack trace to stderr: // Error: Whoops, something bad happened // at [eval]:5:15 // at Script.runInThisContext (node:vm:132:18) // at Object.runInThisContext (node:vm:309:38) // at node:internal/process/execution:77:19 // at [eval]-wrapper:6:22 // at evalScript (node:internal/process/execution:76:60) // at node:internal/main/eval_string:23:3  const name = 'Will Robinson'; console.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
 
const out = getStreamSomehow(); const err = getStreamSomehow(); const myConsole = new console.Console(out, err);  myConsole.log('hello world'); // Prints: hello world, to out myConsole.log('hello %s', 'world'); // Prints: hello world, to out myConsole.error(new Error('Whoops, something bad happened')); // Prints: [Error: Whoops, something bad happened], to err  const name = 'Will Robinson'; myConsole.warn(`Danger ${name}! Danger!`); // Prints: Danger Will Robinson! Danger!, to err
@seesource
console.Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).
 
const count = 5; console.log('count: %d', count); // Prints: count: 5, to stdout console.log('count:', count); // Prints: count: 5, to stdout
See util.format() for more information.
 
@sincev0.1.100
log('second post-processing'); return const result: Responseresult; };  export const const handle: Handlehandle = function sequence(...handlers: Handle[]): Handle
A helper function for sequencing multiple handle calls in a middleware-like manner. The behavior for the handle options is as follows:
 
     
  • transformPageChunk is applied in reverse order and merged
    •  
  • preload is applied in forward order, the first option “wins” and no preload options after it are called
    •  
  • filterSerializedResponseHeaders behaves the same as preload
    •  
 
src/hooks.server
import { sequence } from '@sveltejs/kit/hooks';  /// type: import('@sveltejs/kit').Handle async function first({ event, resolve }) { console.log('first pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { // transforms are applied in reverse order console.log('first transform'); return html; }, preload: () => { // this one wins as it's the first defined in the chain console.log('first preload'); return true; } }); console.log('first post-processing'); return result; }  /// type: import('@sveltejs/kit').Handle async function second({ event, resolve }) { console.log('second pre-processing'); const result = await resolve(event, { transformPageChunk: ({ html }) => { console.log('second transform'); return html; }, preload: () => { console.log('second preload'); return true; }, filterSerializedResponseHeaders: () => { // this one wins as it's the first defined in the chain console.log('second filterSerializedResponseHeaders'); return true; } }); console.log('second post-processing'); return result; }  export const handle = sequence(first, second);
The example above would print:
 
first pre-processing first preload second pre-processing second filterSerializedResponseHeaders second transform first transform second post-processing first post-processing
@paramhandlers The chain of handle functions
sequence(const first: Handlefirst, const second: Handlesecond);

The example above would print:

first pre-processing first preload second pre-processing second filterSerializedResponseHeaders second transform first transform second post-processing first post-processing
function sequence(...handlers: Handle[]): Handle;

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@sveltejs/kit