failure-lambda/dist/types-B8Ty8jhf.d.cts

Failure injection for AWS Lambda - chaos engineering made simple

import { Context, Callback } from 'aws-lambda';

/** The supported failure injection modes */
type FailureMode = "latency" | "exception" | "statuscode" | "diskspace" | "denylist" | "timeout" | "corruption";
/** Match operators for event-based targeting */
type MatchOperator = "eq" | "exists" | "startsWith" | "regex";
/** Condition for event-based targeting */
interface MatchCondition {
    /** Dot-separated path into the event object (e.g. "requestContext.http.method") */
    path: string;
    /** Expected string value at the path. Required for all operators except "exists". */
    value?: string;
    /** Comparison operator. Defaults to "eq". */
    operator?: MatchOperator;
}
/** A single feature flag's value */
interface FlagValue {
    enabled: boolean;
    /** Percentage of invocations to inject (0 to 100, integer). Defaults to 100. */
    percentage?: number;
    /** Minimum latency in ms (latency mode) */
    min_latency?: number;
    /** Maximum latency in ms (latency mode) */
    max_latency?: number;
    /** Error message to throw (exception mode) */
    exception_msg?: string;
    /** HTTP status code to return (statuscode mode) */
    status_code?: number;
    /** MB of disk to fill in /tmp (diskspace mode) */
    disk_space?: number;
    /** Array of regex patterns for hosts to block (denylist mode) */
    deny_list?: string[];
    /** Buffer in ms before Lambda timeout (timeout mode). Default: 0 */
    timeout_buffer_ms?: number;
    /** Replacement body string (corruption mode) */
    body?: string;
    /** Event-based targeting conditions. All conditions must match for the flag to fire. */
    match?: MatchCondition[];
}
/** The full config: a map of failure mode names to their flag values */
type FailureFlagsConfig = Partial<Record<FailureMode, FlagValue>>;
/** A failure resolved and ready to inject */
interface ResolvedFailure {
    mode: FailureMode;
    percentage: number;
    flag: FlagValue;
}
/**
 * Generic Lambda handler type. Intentionally broad to support any
 * event source (API Gateway, SQS, SNS, EventBridge, etc.).
 */
type LambdaHandler<TEvent = unknown, TResult = unknown> = (event: TEvent, context: Context, callback: Callback<TResult>) => void | Promise<TResult>;
/** Options for the injectFailure wrapper */
interface FailureLambdaOptions {
    /** Override the config source (useful for testing or custom config backends) */
    configProvider?: () => Promise<FailureFlagsConfig>;
    /** Log which failures would fire without actually injecting them */
    dryRun?: boolean;
}
/** Validation error detail */
interface ConfigValidationError {
    field: string;
    message: string;
    value: unknown;
}

export type { ConfigValidationError as C, FailureFlagsConfig as F, LambdaHandler as L, MatchCondition as M, ResolvedFailure as R, FailureLambdaOptions as a, FailureMode as b, FlagValue as c, MatchOperator as d };