@bitblit/epsilon
Version:
Tiny adapter to simplify building API gateway Lambda APIS
254 lines • 13.3 kB
JavaScript
;
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (_) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
Object.defineProperty(exports, "__esModule", { value: true });
var logger_1 = require("@bitblit/ratchet/dist/common/logger");
var map_ratchet_1 = require("@bitblit/ratchet/dist/common/map-ratchet");
var zlib = require("zlib");
var epsilon_constants_1 = require("../epsilon-constants");
var string_ratchet_1 = require("@bitblit/ratchet/dist/common/string-ratchet");
var ResponseUtil = /** @class */ (function () {
function ResponseUtil() {
} // Prevent instantiation
ResponseUtil.errorResponse = function (errorMessages, statusCode, reqId) {
var body = {
errors: errorMessages,
httpStatusCode: statusCode,
requestId: reqId || 'MISSING'
};
var errorResponse = {
statusCode: statusCode,
isBase64Encoded: false,
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify(body)
};
return errorResponse;
};
ResponseUtil.redirect = function (target, code, queryParams) {
if (code === void 0) { code = 301; }
if (queryParams === void 0) { queryParams = null; }
if (code !== 301 && code !== 302) {
throw new Error('Code must be 301 or 302 for a redirect');
}
var redirectTarget = target;
if (queryParams) {
var keys = Object.keys(queryParams);
if (keys.length > 0) {
logger_1.Logger.silly('Applying params to input target : %j', queryParams);
redirectTarget += redirectTarget.indexOf('?') === -1 ? '?' : '&';
for (var i = 0; i < keys.length; i++) {
var k = keys[i];
// TODO: make sure not double encoding
redirectTarget += k + '=' + encodeURIComponent(queryParams[k]);
if (i < keys.length - 1) {
redirectTarget += '&';
}
}
}
}
return {
statusCode: code,
body: '{"redirect-target":"' + redirectTarget + '}',
headers: {
'Content-Type': 'application/json',
Location: redirectTarget
}
};
};
ResponseUtil.buildHttpError = function (errorMessage, statusCode) {
var rval = new Error(errorMessage);
rval['statusCode'] = statusCode;
return rval;
};
ResponseUtil.errorToProxyResult = function (error, reqId, defaultErrorMessage) {
if (defaultErrorMessage === void 0) { defaultErrorMessage = null; }
var code = error['statusCode'] || 500;
var errorMessages = null;
if (!!string_ratchet_1.StringRatchet.trimToNull(defaultErrorMessage) && code === 500) {
// Basically the 'Internal Server Error' info hiding use case
errorMessages = [defaultErrorMessage];
}
else {
errorMessages = error['messages'] && error['messages'].length > 0 ? error['messages'] : null;
errorMessages = errorMessages ? errorMessages : [error.message || JSON.stringify(error)];
}
return ResponseUtil.errorResponse(errorMessages, code, reqId);
};
ResponseUtil.coerceToProxyResult = function (input) {
var rval = null;
if (input != null) {
if (typeof input === 'object') {
if (input.statusCode && input.body !== undefined) {
rval = Object.assign({}, input);
if (typeof input.body === 'string') {
// Do Nothing
}
else if (Buffer.isBuffer(input.body)) {
rval.body = input.body.toString('base64');
rval.headers = input.headers || {};
rval.headers['Content-Type'] = input.body.contentType; // TODO: Does this work?
rval.isBase64Encoded = true;
}
}
else {
// Its a generic object
var headers = input.headers || {};
headers['Content-Type'] = 'application/json';
rval = ResponseUtil.coerceToProxyResult({
statusCode: 200,
body: JSON.stringify(input),
headers: headers,
isBase64Encoded: false
});
}
}
else if (typeof input === 'string' || Buffer.isBuffer(input)) {
rval = ResponseUtil.coerceToProxyResult({ statusCode: 200, body: input });
}
else {
// boolean , number, etc - other top level types
// See : https://stackoverflow.com/questions/18419428/what-is-the-minimum-valid-json
var headers = input.headers || {};
headers['Content-Type'] = 'application/json';
rval = ResponseUtil.coerceToProxyResult({
statusCode: 200,
body: JSON.stringify(input),
headers: headers,
isBase64Encoded: false
});
}
}
return rval;
};
// Public so it can be used in auth-web-handler
ResponseUtil.addCORSToProxyResult = function (input, cfg, srcEvent) {
input.headers = input.headers || {};
srcEvent.headers = srcEvent.headers || {};
// Matching the request is mainly here to support old safari browsers
var targetOrigin = cfg.corsAllowedOrigins !== epsilon_constants_1.EpsilonConstants.CORS_MATCH_REQUEST_FLAG
? cfg.corsAllowedOrigins
: ResponseUtil.buildReflectCorsAllowOrigin(srcEvent, '*');
var targetHeaders = cfg.corsAllowedHeaders !== epsilon_constants_1.EpsilonConstants.CORS_MATCH_REQUEST_FLAG
? cfg.corsAllowedHeaders
: ResponseUtil.buildReflectCorsAllowHeaders(srcEvent, '*');
var targetMethod = cfg.corsAllowedMethods !== epsilon_constants_1.EpsilonConstants.CORS_MATCH_REQUEST_FLAG
? cfg.corsAllowedMethods
: ResponseUtil.buildReflectCorsAllowMethods(srcEvent, '*');
logger_1.Logger.silly('Adding CORS to proxy result tOrigin: %s tHeaders: %s tMethod: %s', targetOrigin, targetHeaders, targetMethod);
if (string_ratchet_1.StringRatchet.trimToNull(string_ratchet_1.StringRatchet.safeString(input.headers['Access-Control-Allow-Origin'])) === null && !!targetOrigin) {
input.headers['Access-Control-Allow-Origin'] = targetOrigin;
}
if (string_ratchet_1.StringRatchet.trimToNull(string_ratchet_1.StringRatchet.safeString(input.headers['Access-Control-Allow-Methods'])) === null && !!targetMethod) {
input.headers['Access-Control-Allow-Methods'] = targetMethod;
}
if (string_ratchet_1.StringRatchet.trimToNull(string_ratchet_1.StringRatchet.safeString(input.headers['Access-Control-Allow-Headers'])) === null && !!targetHeaders) {
input.headers['Access-Control-Allow-Headers'] = targetHeaders;
}
return input;
};
ResponseUtil.buildReflectCorsAllowOrigin = function (srcEvent, defaultValue) {
if (defaultValue === void 0) { defaultValue = '*'; }
var rval = map_ratchet_1.MapRatchet.caseInsensitiveAccess(srcEvent.headers, 'Origin') || defaultValue;
return rval;
};
ResponseUtil.buildReflectCorsAllowHeaders = function (srcEvent, defaultValue) {
if (defaultValue === void 0) { defaultValue = '*'; }
var rval = map_ratchet_1.MapRatchet.caseInsensitiveAccess(srcEvent.headers, 'Access-Control-Request-Headers') ||
Object.keys(srcEvent.headers).join(', ') ||
'*';
return rval;
};
ResponseUtil.buildReflectCorsAllowMethods = function (srcEvent, defaultValue) {
if (defaultValue === void 0) { defaultValue = '*'; }
var rval = map_ratchet_1.MapRatchet.caseInsensitiveAccess(srcEvent.headers, 'Access-Control-Request-Method') ||
srcEvent.httpMethod.toUpperCase() ||
'*';
return rval;
};
ResponseUtil.applyGzipIfPossible = function (encodingHeader, proxyResult) {
return __awaiter(this, void 0, void 0, function () {
var rval, bigEnough, contentType, exemptContent, asBuffer, zipped, zipped64;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
rval = proxyResult;
if (!(encodingHeader && encodingHeader.toLowerCase().indexOf('gzip') > -1)) return [3 /*break*/, 4];
bigEnough = proxyResult.body.length > 1400;
contentType = map_ratchet_1.MapRatchet.extractValueFromMapIgnoreCase(proxyResult.headers, 'content-type') || '';
contentType = contentType.toLowerCase();
exemptContent = contentType === 'application/pdf' || contentType === 'application/zip' || contentType.startsWith('image/');
if (!(bigEnough && !exemptContent)) return [3 /*break*/, 2];
asBuffer = proxyResult.isBase64Encoded ? Buffer.from(proxyResult.body, 'base64') : Buffer.from(proxyResult.body);
return [4 /*yield*/, this.gzip(asBuffer)];
case 1:
zipped = _a.sent();
logger_1.Logger.silly('Comp from %d to %d bytes', asBuffer.length, zipped.length);
zipped64 = zipped.toString('base64');
rval.body = zipped64;
rval.isBase64Encoded = true;
rval.headers = rval.headers || {};
rval.headers['Content-Encoding'] = 'gzip';
return [3 /*break*/, 3];
case 2:
logger_1.Logger.silly('Not gzipping, too small or exempt content');
_a.label = 3;
case 3: return [3 /*break*/, 5];
case 4:
logger_1.Logger.silly('Not gzipping, not an accepted encoding');
_a.label = 5;
case 5: return [2 /*return*/, rval];
}
});
});
};
ResponseUtil.gzip = function (input) {
var promise = new Promise(function (resolve, reject) {
zlib.gzip(input, function (error, result) {
if (!error)
resolve(result);
else
reject(error);
});
});
return promise;
};
return ResponseUtil;
}());
exports.ResponseUtil = ResponseUtil;
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