counterfact/dist/server/response-validator.js

Generate a TypeScript-based mock server from an OpenAPI spec in seconds — with stateful routes, hot reload, and REPL support.

import Ajv from "ajv";
const ajv = new Ajv({
    allErrors: true,
    strict: false,
    coerceTypes: false,
});
export function validateResponse(operation, response) {
    if (!operation) {
        return { errors: [], valid: true };
    }
    const errors = [];
    const statusKey = response.status !== undefined ? String(response.status) : undefined;
    const responseSpec = (statusKey !== undefined ? operation.responses[statusKey] : undefined) ??
        operation.responses.default;
    if (!responseSpec) {
        return { errors: [], valid: true };
    }
    const specHeaders = responseSpec.headers ?? {};
    const actualHeaders = response.headers ?? {};
    for (const [name, headerSpec] of Object.entries(specHeaders)) {
        const actualValue = actualHeaders[name] ?? actualHeaders[name.toLowerCase()];
        if (headerSpec.required === true && actualValue === undefined) {
            errors.push(`response header '${name}' is required`);
            continue;
        }
        if (actualValue !== undefined && headerSpec.schema !== undefined) {
            const coercedValue = typeof actualValue === "string"
                ? coerceHeaderValue(actualValue, headerSpec.schema)
                : actualValue;
            const valid = ajv.validate(headerSpec.schema, coercedValue);
            if (!valid && ajv.errors) {
                for (const error of ajv.errors) {
                    const path = error.instancePath ?? "";
                    errors.push(`response header '${name}'${path} ${error.message ?? "is invalid"}`);
                }
            }
        }
    }
    return {
        errors,
        valid: errors.length === 0,
    };
}
function coerceHeaderValue(value, schema) {
    const type = schema.type;
    if (type === "integer" || type === "number") {
        const num = Number(value);
        return Number.isNaN(num) ? value : num;
    }
    if (type === "boolean") {
        if (value === "true")
            return true;
        if (value === "false")
            return false;
        return value;
    }
    return value;
}