Implementation:Webdriverio Webdriverio Config Constants

Knowledge Sources	Webdriverio_Webdriverio
Domains	Configuration, Defaults
Last Updated	2026-02-12 00:00 GMT

Overview

Default configuration values, supported hook definitions, supported file extensions, and error messages used as the foundation for WebdriverIO testrunner configuration initialization and validation.

Description

This module exports the core configuration constants that underpin the WebdriverIO testrunner. The DEFAULT_CONFIGS factory function returns a complete WebdriverIO.Config object with sensible defaults for all configuration properties including specs, capabilities, logging, timeouts, framework options, and every lifecycle hook initialized as an empty array. SUPPORTED_HOOKS enumerates all recognized hook names used for configuration validation. SUPPORTED_FILE_EXTENSIONS lists the file extensions that WebdriverIO recognizes for spec and configuration files. NO_NAMED_CONFIG_EXPORT provides the error message shown when a configuration file lacks the expected named export.

Usage

Use DEFAULT_CONFIGS() when you need to obtain a baseline configuration object to merge with user-provided options (as done by defineConfig()). Reference SUPPORTED_HOOKS when validating or iterating over hook definitions in configuration processing. Check SUPPORTED_FILE_EXTENSIONS when resolving or filtering spec files. These constants are consumed internally by the config loader and validator, and are also useful for tooling that generates or manipulates WebdriverIO configurations.

Code Reference

Source Location

Repository: Webdriverio_Webdriverio
File: packages/wdio-config/src/constants.ts
Lines: 1-110

Signature

export const DEFAULT_CONFIGS: () => WebdriverIO.Config = () => ({
    specs: [],
    suites: {},
    exclude: [],
    capabilities: [],
    outputDir: undefined,
    logLevel: 'info' as const,
    logLevels: {},
    groupLogsByTestSpec: false,
    excludeDriverLogs: [],
    bail: 0,
    waitforInterval: 100,
    waitforTimeout: 5000,
    framework: 'mocha' as const,
    reporters: [],
    services: [],
    maxInstances: 100,
    maxInstancesPerCapability: 100,
    injectGlobals: true,
    filesToWatch: [],
    connectionRetryTimeout: 120000,
    connectionRetryCount: 3,
    execArgv: [],
    runnerEnv: {},
    runner: 'local' as const,
    shard: { current: 1, total: 1 },
    specFileRetries: 0,
    specFileRetriesDelay: 0,
    specFileRetriesDeferred: false,
    autoAssertOnTestEnd: true,
    reporterSyncInterval: 100,
    reporterSyncTimeout: 5000,
    cucumberFeaturesWithLineNumbers: [],
    // framework defaults
    mochaOpts: { timeout: 10000 },
    jasmineOpts: { defaultTimeoutInterval: 10000 },
    cucumberOpts: { timeout: 10000 },
    // hooks (all initialized as empty arrays)
    onPrepare: [], onWorkerStart: [], onWorkerEnd: [],
    before: [], beforeSession: [], beforeSuite: [],
    beforeHook: [], beforeTest: [], beforeCommand: [],
    afterCommand: [], afterTest: [], afterHook: [],
    afterSuite: [], afterSession: [], after: [],
    onComplete: [], onReload: [],
    beforeAssertion: [], afterAssertion: [],
    // cucumber hooks
    beforeFeature: [], beforeScenario: [], beforeStep: [],
    afterStep: [], afterScenario: [], afterFeature: []
})

export const DEFAULT_MAX_INSTANCES_PER_CAPABILITY_VALUE = 100

export const SUPPORTED_HOOKS: (keyof Services.Hooks)[] = [
    'before', 'beforeSession', 'beforeSuite', 'beforeHook',
    'beforeTest', 'beforeCommand', 'afterCommand', 'afterTest',
    'afterHook', 'afterSuite', 'afterSession', 'after',
    'beforeAssertion', 'afterAssertion',
    'beforeFeature', 'beforeScenario', 'beforeStep',
    'afterStep', 'afterScenario', 'afterFeature',
    'onReload', 'onPrepare', 'onWorkerStart', 'onWorkerEnd', 'onComplete'
]

export const SUPPORTED_FILE_EXTENSIONS = [
    '.js', '.jsx', '.mjs', '.mts', '.es6',
    '.ts', '.tsx', '.feature', '.coffee', '.cjs'
]

export const NO_NAMED_CONFIG_EXPORT = (
    'No named export object called "config" found. ...'
)

Import

import {
    DEFAULT_CONFIGS,
    SUPPORTED_HOOKS,
    SUPPORTED_FILE_EXTENSIONS,
    DEFAULT_MAX_INSTANCES_PER_CAPABILITY_VALUE,
    NO_NAMED_CONFIG_EXPORT
} from '@wdio/config'

I/O Contract

Exported Constants
Name	Type	Value/Return	Description
`DEFAULT_CONFIGS`	`() => WebdriverIO.Config`	Complete config object	Factory returning default configuration with all properties set
`DEFAULT_MAX_INSTANCES_PER_CAPABILITY_VALUE`	`number`	`100`	Default maximum parallel instances per capability
`SUPPORTED_HOOKS`	`(keyof Services.Hooks)[]`	Array of 23 hook names	All supported lifecycle hook names for validation
`SUPPORTED_FILE_EXTENSIONS`	`string[]`	10 extensions	File extensions recognized by spec file resolution
`NO_NAMED_CONFIG_EXPORT`	`string`	Error message	Message shown when config file lacks named export

Key Default Values
Property	Default	Type	Notes
`logLevel`	`'info'`	`string`	Logging verbosity
`bail`	`0`	`number`	0 means run all tests regardless of failures
`waitforTimeout`	`5000`	`number`	5 seconds for waitFor* commands
`waitforInterval`	`100`	`number`	100ms polling interval
`framework`	`'mocha'`	`string`	Default test framework
`maxInstances`	`100`	`number`	Maximum total parallel workers
`connectionRetryTimeout`	`120000`	`number`	2 minutes WebDriver request timeout
`connectionRetryCount`	`3`	`number`	Number of request retries
`runner`	`'local'`	`string`	Default runner type
`specFileRetries`	`0`	`number`	No spec file retries by default
`mochaOpts.timeout`	`10000`	`number`	10 second Mocha test timeout

Usage Examples

import {
    DEFAULT_CONFIGS,
    SUPPORTED_HOOKS,
    SUPPORTED_FILE_EXTENSIONS
} from '@wdio/config'

// Get default configuration and merge with user options
const defaults = DEFAULT_CONFIGS()
const userConfig: Partial<WebdriverIO.Config> = {
    specs: ['./test/**/*.spec.ts'],
    maxInstances: 5,
    logLevel: 'warn'
}
const mergedConfig = { ...defaults, ...userConfig }

// Validate that a hook name is supported
function isValidHook(hookName: string): boolean {
    return SUPPORTED_HOOKS.includes(hookName as keyof Services.Hooks)
}

// Filter spec files by supported extensions
function isSupported(filePath: string): boolean {
    return SUPPORTED_FILE_EXTENSIONS.some(ext => filePath.endsWith(ext))
}
const specFiles = ['login.spec.ts', 'data.json', 'checkout.feature']
const validSpecs = specFiles.filter(isSupported)
// Result: ['login.spec.ts', 'checkout.feature']

// Iterate over all hooks in configuration
for (const hookName of SUPPORTED_HOOKS) {
    const hookValue = mergedConfig[hookName]
    if (Array.isArray(hookValue) && hookValue.length > 0) {
        console.log(`Hook "${hookName}" has ${hookValue.length} handler(s)`)
    }
}

// Access specific default values
console.log(`Default framework: ${defaults.framework}`)       // 'mocha'
console.log(`Default max instances: ${defaults.maxInstances}`) // 100
console.log(`Default retry timeout: ${defaults.connectionRetryTimeout}`) // 120000

Related Pages

Principle:Webdriverio_Webdriverio_Configuration_Management
Implementation:Webdriverio_Webdriverio_Config_Utils - Uses DEFAULT_CONFIGS in defineConfig()
Implementation:Webdriverio_Webdriverio_Options_Types - Type definitions for properties in DEFAULT_CONFIGS
Implementation:Webdriverio_Webdriverio_Services_Types - Hooks type referenced by SUPPORTED_HOOKS

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