@vercel/flags/dist/next.js

Flags SDK by Vercel - The feature flags toolkit for Next.js and SvelteKit

import {
  normalizeOptions
} from "./chunk-ZNKTXALY.js";
import {
  HeadersAdapter,
  RequestCookiesAdapter,
  decrypt,
  internalReportValue,
  reportValue,
  setSpanAttribute,
  trace
} from "./chunk-43J6AE7X.js";
import "./chunk-2UDLZC33.js";

// src/next/index.ts
import { RequestCookies } from "@edge-runtime/cookies";

// src/next/async-memoize-one.ts
function memoizeOne(fn, isEqual, { cachePromiseRejection = false } = {}) {
  let calledOnce = false;
  let oldArgs;
  let lastResult;
  function memoized(...newArgs) {
    if (calledOnce && isEqual(newArgs, oldArgs))
      return lastResult;
    lastResult = fn.apply(this, newArgs);
    if (!cachePromiseRejection && lastResult.catch) {
      lastResult.catch(() => calledOnce = false);
    }
    calledOnce = true;
    oldArgs = newArgs;
    return lastResult;
  }
  return memoized;
}

// src/next/overrides.ts
var memoizedDecrypt = memoizeOne(
  (text) => decrypt(text),
  (a, b) => a[0] === b[0],
  // only the first argument gets compared
  { cachePromiseRejection: true }
);
async function getOverrides(cookie) {
  if (typeof cookie === "string" && cookie !== "") {
    const cookieOverrides = await memoizedDecrypt(cookie);
    return cookieOverrides ?? null;
  }
  return null;
}

// src/next/serialization.ts
import { CompactSign, base64url, compactVerify } from "jose";
var memoizedVerify = memoizeOne(
  (code, secret) => compactVerify(code, base64url.decode(secret), {
    algorithms: ["HS256"]
  }),
  (a, b) => a[0] === b[0] && a[1] === b[1],
  // only first two args matter
  { cachePromiseRejection: true }
);
var memoizedSign = memoizeOne(
  (uint8Array, secret) => new CompactSign(uint8Array).setProtectedHeader({ alg: "HS256" }).sign(base64url.decode(secret)),
  (a, b) => (
    // matchedIndices array must be equal
    a[0].length === b[0].length && a[0].every((v, i) => b[0][i] === v) && // secrets must be equal
    a[1] === b[1]
  ),
  { cachePromiseRejection: true }
);
function splitUint8Array(array, index) {
  const firstHalf = array.slice(0, index);
  const secondHalf = array.slice(index);
  return [firstHalf, secondHalf];
}
async function deserialize(code, flags, secret) {
  const { payload } = await memoizedVerify(code, secret);
  const [matchedIndicesArray, valuesUint8Array] = payload.length === flags.length ? [payload] : splitUint8Array(payload, flags.length);
  const valuesArray = valuesUint8Array ? (
    // re-add opening and closing brackets since we remove them when serializing
    JSON.parse(`[${new TextDecoder().decode(valuesUint8Array)}]`)
  ) : null;
  let spilled = 0;
  return matchedIndicesArray.reduce(
    (acc, valueIndex, index) => {
      const flag2 = flags[index];
      if (!flag2) {
        throw new Error(`@vercel/flags: No flag at index ${index}`);
      }
      switch (valueIndex) {
        case 253 /* BOOLEAN_FALSE */:
          acc[flag2.key] = false;
          break;
        case 254 /* BOOLEAN_TRUE */:
          acc[flag2.key] = true;
          break;
        case 255 /* UNLISTED_VALUE */:
          acc[flag2.key] = valuesArray[spilled++];
          break;
        case 252 /* NULL */:
          acc[flag2.key] = null;
          break;
        default:
          acc[flag2.key] = flag2.options?.[valueIndex]?.value;
      }
      return acc;
    },
    {}
  );
}
var matchIndex = /* @__PURE__ */ function() {
  const stringifiedOptionsCache = /* @__PURE__ */ new Map();
  return function matchIndex2(options, value) {
    const t = typeof value;
    if (value === null || t === "boolean" || t === "string" || t === "number") {
      return options.findIndex((v) => v.value === value);
    }
    const stringifiedValue = JSON.stringify(value);
    let stringifiedOptions = stringifiedOptionsCache.get(options);
    if (!stringifiedOptions) {
      stringifiedOptions = options.map((o) => JSON.stringify(o.value));
      stringifiedOptionsCache.set(options, stringifiedOptions);
    }
    return stringifiedOptions.findIndex(
      (stringifiedOption) => stringifiedOption === stringifiedValue
    );
  };
}();
function joinUint8Arrays(array1, array2) {
  const combined = new Uint8Array(array1.length + array2.length);
  combined.set(array1);
  combined.set(array2, array1.length);
  return combined;
}
async function serialize(flagSet, flags, secret) {
  const unlistedValues = [];
  const matchedIndices = new Uint8Array(
    flags.map((flag2) => {
      const options = Array.isArray(flag2.options) ? flag2.options : [];
      const value = flagSet[flag2.key];
      if (!Object.prototype.hasOwnProperty.call(flagSet, flag2.key) || value === void 0) {
        throw new Error(`@vercel/flags: Missing value for flag "${flag2.key}"`);
      }
      switch (value) {
        case null:
          return 252 /* NULL */;
        case false:
          return 253 /* BOOLEAN_FALSE */;
        case true:
          return 254 /* BOOLEAN_TRUE */;
      }
      const matchedIndex = matchIndex(options, value);
      if (matchedIndex > -1)
        return matchedIndex;
      unlistedValues.push(value);
      return 255 /* UNLISTED_VALUE */;
    })
  );
  let joined;
  if (unlistedValues.length > 0) {
    const jsonArray = new TextEncoder().encode(
      // slicing removes opening and closing array brackets as they'll always be
      //  there and we can re-add them when deserializing
      JSON.stringify(unlistedValues).slice(1, -1)
    );
    joined = joinUint8Arrays(matchedIndices, jsonArray);
  } else {
    joined = matchedIndices;
  }
  return memoizedSign(joined, secret);
}

// src/next/precompute.ts
async function evaluate(flags) {
  return Promise.all(flags.map((flag2) => flag2()));
}
async function precompute(flags) {
  const values = await evaluate(flags);
  return serialize2(flags, values);
}
function combine(flags, values) {
  return Object.fromEntries(flags.map((flag2, i) => [flag2.key, values[i]]));
}
async function serialize2(flags, values, secret = process.env.FLAGS_SECRET) {
  if (!secret) {
    throw new Error("@vercel/flags: Can not serialize due to missing secret");
  }
  return serialize(combine(flags, values), flags, secret);
}
async function deserialize2(flags, code, secret = process.env.FLAGS_SECRET) {
  if (!secret) {
    throw new Error("@vercel/flags: Can not serialize due to missing secret");
  }
  return deserialize(code, flags, secret);
}
async function getPrecomputed(flagOrFlags, precomputeFlags, code, secret = process.env.FLAGS_SECRET) {
  if (!secret) {
    throw new Error(
      "@vercel/flags: getPrecomputed was called without a secret. Please set FLAGS_SECRET environment variable."
    );
  }
  const flagSet = await deserialize2(precomputeFlags, code, secret);
  if (Array.isArray(flagOrFlags)) {
    return flagOrFlags.map((flag2) => flagSet[flag2.key]);
  } else {
    return flagSet[flagOrFlags.key];
  }
}
function* cartesianIterator(items) {
  const remainder = items.length > 1 ? cartesianIterator(items.slice(1)) : [[]];
  for (let r of remainder)
    for (let h of items.at(0))
      yield [h, ...r];
}
async function generatePermutations(flags, filter = null, secret = process.env.FLAGS_SECRET) {
  if (!secret) {
    throw new Error(
      "@vercel/flags: generatePermutations was called without a secret. Please set FLAGS_SECRET environment variable."
    );
  }
  const options = flags.map((flag2) => {
    if (!flag2.options)
      return [false, true];
    return flag2.options.map((option) => option.value);
  });
  const list = [];
  for (const permutation of cartesianIterator(options)) {
    const permObject = permutation.reduce(
      (acc, value, index) => {
        acc[flags[index].key] = value;
        return acc;
      },
      {}
    );
    if (!filter || filter(permObject))
      list.push(permObject);
  }
  return Promise.all(list.map((values) => serialize(values, flags, secret)));
}

// src/next/is-internal-next-error.ts
var REACT_POSTPONE_TYPE = Symbol.for("react.postpone");
function isPostpone(error) {
  return typeof error === "object" && error !== null && "$$typeof" in error && error.$$typeof === REACT_POSTPONE_TYPE;
}
function isInternalNextError(error) {
  if (isPostpone(error))
    return true;
  if (typeof error !== "object" || error === null || !("digest" in error) || typeof error.digest !== "string") {
    return false;
  }
  const errorCode = error.digest.split(";")[0];
  return errorCode === "NEXT_REDIRECT" || errorCode === "DYNAMIC_SERVER_USAGE" || errorCode === "BAILOUT_TO_CLIENT_SIDE_RENDERING" || errorCode === "NEXT_NOT_FOUND";
}

// src/next/dedupe.ts
function createCacheNode() {
  return {
    s: 0 /* UNTERMINATED */,
    v: void 0,
    o: null,
    p: null
  };
}
function dedupe(fn) {
  const requestStore = /* @__PURE__ */ new WeakMap();
  return async function(...args) {
    const { headers } = await import("next/headers");
    const h = await headers();
    let cacheNode = requestStore.get(h);
    if (!cacheNode) {
      cacheNode = createCacheNode();
      requestStore.set(h, cacheNode);
    }
    for (let i = 0; i < args.length; i++) {
      const arg = args[i];
      if (typeof arg === "function" || typeof arg === "object" && arg !== null) {
        let objectCache = cacheNode.o;
        if (objectCache === null) {
          cacheNode.o = objectCache = /* @__PURE__ */ new WeakMap();
        }
        const objectNode = objectCache.get(arg);
        if (objectNode === void 0) {
          cacheNode = createCacheNode();
          objectCache.set(arg, cacheNode);
        } else {
          cacheNode = objectNode;
        }
      } else {
        let primitiveCache = cacheNode.p;
        if (primitiveCache === null) {
          cacheNode.p = primitiveCache = /* @__PURE__ */ new Map();
        }
        const primitiveNode = primitiveCache.get(arg);
        if (primitiveNode === void 0) {
          cacheNode = createCacheNode();
          primitiveCache.set(arg, cacheNode);
        } else {
          cacheNode = primitiveNode;
        }
      }
    }
    if (cacheNode.s === 1 /* TERMINATED */) {
      return cacheNode.v;
    }
    if (cacheNode.s === 2 /* ERRORED */) {
      throw cacheNode.v;
    }
    try {
      const result = fn.apply(this, args);
      cacheNode.s = 1 /* TERMINATED */;
      cacheNode.v = result;
      return result;
    } catch (error) {
      cacheNode.s = 2 /* ERRORED */;
      cacheNode.v = error;
      throw error;
    }
  };
}

// src/next/index.ts
var evaluationCache = /* @__PURE__ */ new WeakMap();
function getCachedValuePromise(headers, flagKey, entitiesKey) {
  const map = evaluationCache.get(headers)?.get(flagKey);
  if (!map)
    return void 0;
  return map.get(entitiesKey);
}
function setCachedValuePromise(headers, flagKey, entitiesKey, flagValue) {
  const byHeaders = evaluationCache.get(headers);
  if (!byHeaders) {
    evaluationCache.set(
      headers,
      /* @__PURE__ */ new Map([[flagKey, /* @__PURE__ */ new Map([[entitiesKey, flagValue]])]])
    );
    return;
  }
  const byFlagKey = byHeaders.get(flagKey);
  if (!byFlagKey) {
    byHeaders.set(flagKey, /* @__PURE__ */ new Map([[entitiesKey, flagValue]]));
    return;
  }
  byFlagKey.set(entitiesKey, flagValue);
}
var transformMap = /* @__PURE__ */ new WeakMap();
var headersMap = /* @__PURE__ */ new WeakMap();
var cookiesMap = /* @__PURE__ */ new WeakMap();
var identifyArgsMap = /* @__PURE__ */ new WeakMap();
function transformToHeaders(incomingHeaders) {
  const cached = transformMap.get(incomingHeaders);
  if (cached !== void 0)
    return cached;
  const headers = new Headers();
  for (const [key, value] of Object.entries(incomingHeaders)) {
    if (Array.isArray(value)) {
      value.forEach((item) => headers.append(key, item));
    } else if (value !== void 0) {
      headers.append(key, value);
    }
  }
  transformMap.set(incomingHeaders, headers);
  return headers;
}
function sealHeaders(headers) {
  const cached = headersMap.get(headers);
  if (cached !== void 0)
    return cached;
  const sealed = HeadersAdapter.seal(headers);
  headersMap.set(headers, sealed);
  return sealed;
}
function sealCookies(headers) {
  const cached = cookiesMap.get(headers);
  if (cached !== void 0)
    return cached;
  const sealed = RequestCookiesAdapter.seal(new RequestCookies(headers));
  cookiesMap.set(headers, sealed);
  return sealed;
}
function isIdentifyFunction(identify) {
  return typeof identify === "function";
}
async function getEntities(identify, dedupeCacheKey, readonlyHeaders, readonlyCookies) {
  if (!identify)
    return void 0;
  if (!isIdentifyFunction(identify))
    return identify;
  const args = identifyArgsMap.get(dedupeCacheKey);
  if (args)
    return identify(...args);
  const nextArgs = [
    { headers: readonlyHeaders, cookies: readonlyCookies }
  ];
  identifyArgsMap.set(dedupeCacheKey, nextArgs);
  return identify(...nextArgs);
}
function getDecide(definition) {
  return function decide(params) {
    if (typeof definition.decide === "function") {
      return definition.decide(params);
    }
    if (typeof definition.adapter?.decide === "function") {
      return definition.adapter.decide({ key: definition.key, ...params });
    }
    throw new Error(
      `@vercel/flags: No decide function provided for ${definition.key}`
    );
  };
}
function getIdentify(definition) {
  return function identify(params) {
    if (typeof definition.identify === "function") {
      return definition.identify(params);
    }
    if (typeof definition.adapter?.identify === "function") {
      return definition.adapter.identify(params);
    }
    return definition.identify;
  };
}
function getRun(definition, decide) {
  return async function run(options) {
    let readonlyHeaders;
    let readonlyCookies;
    let dedupeCacheKey;
    if (options.request) {
      const headers = transformToHeaders(options.request.headers);
      readonlyHeaders = sealHeaders(headers);
      readonlyCookies = sealCookies(headers);
      dedupeCacheKey = options.request.headers;
    } else {
      const { headers, cookies } = await import("next/headers");
      const [headersStore, cookiesStore] = await Promise.all([
        headers(),
        cookies()
      ]);
      readonlyHeaders = headersStore;
      readonlyCookies = cookiesStore;
      dedupeCacheKey = headersStore;
    }
    const overrides = await getOverrides(
      readonlyCookies.get("vercel-flag-overrides")?.value
    );
    const entities = await getEntities(
      options.identify,
      dedupeCacheKey,
      readonlyHeaders,
      readonlyCookies
    );
    const entitiesKey = JSON.stringify(entities) ?? "";
    const cachedValue = getCachedValuePromise(
      readonlyHeaders,
      definition.key,
      entitiesKey
    );
    if (cachedValue !== void 0) {
      setSpanAttribute("method", "cached");
      const value = await cachedValue;
      return value;
    }
    if (overrides && overrides[definition.key] !== void 0) {
      setSpanAttribute("method", "override");
      const decision2 = overrides[definition.key];
      setCachedValuePromise(
        readonlyHeaders,
        definition.key,
        entitiesKey,
        Promise.resolve(decision2)
      );
      internalReportValue(definition.key, decision2, {
        reason: "override"
      });
      return decision2;
    }
    const decisionPromise = (async () => {
      return decide({
        headers: readonlyHeaders,
        cookies: readonlyCookies,
        entities
      });
    })().then(
      (value) => {
        if (value !== void 0)
          return value;
        if (definition.defaultValue !== void 0)
          return definition.defaultValue;
        throw new Error(
          `@vercel/flags: Flag "${definition.key}" must have a defaultValue or a decide function that returns a value`
        );
      },
      (error) => {
        if (isInternalNextError(error))
          throw error;
        if (definition.defaultValue !== void 0) {
          if (process.env.NODE_ENV === "development") {
            console.info(
              `@vercel/flags: Flag "${definition.key}" is falling back to its defaultValue`
            );
          } else {
            console.warn(
              `@vercel/flags: Flag "${definition.key}" is falling back to its defaultValue after catching the following error`,
              error
            );
          }
          return definition.defaultValue;
        }
        console.warn(
          `@vercel/flags: Flag "${definition.key}" could not be evaluated`
        );
        throw error;
      }
    );
    setCachedValuePromise(
      readonlyHeaders,
      definition.key,
      entitiesKey,
      decisionPromise
    );
    const decision = await decisionPromise;
    if (definition.config?.reportValue !== false) {
      reportValue(definition.key, decision);
    }
    return decision;
  };
}
function getOrigin(definition) {
  if (definition.origin)
    return definition.origin;
  if (typeof definition.adapter?.origin === "function")
    return definition.adapter.origin(definition.key);
  return definition.adapter?.origin;
}
function flag(definition) {
  const decide = getDecide(definition);
  const identify = getIdentify(definition);
  const run = getRun(definition, decide);
  const origin = getOrigin(definition);
  const flag2 = trace(
    async (...args) => {
      setSpanAttribute("method", "decided");
      if (typeof args[0] === "string" && Array.isArray(args[1])) {
        const [precomputedCode, precomputedGroup, secret] = args;
        if (precomputedCode && precomputedGroup) {
          setSpanAttribute("method", "precomputed");
          return getPrecomputed(
            flag2,
            precomputedGroup,
            precomputedCode,
            secret
          );
        }
      }
      if (args[0] && typeof args[0] === "object" && "headers" in args[0]) {
        const [request] = args;
        return run({ identify, request });
      }
      return run({ identify, request: void 0 });
    },
    {
      name: "flag",
      isVerboseTrace: false,
      attributes: { key: definition.key }
    }
  );
  flag2.key = definition.key;
  flag2.defaultValue = definition.defaultValue;
  flag2.origin = origin;
  flag2.options = normalizeOptions(definition.options);
  flag2.description = definition.description;
  flag2.identify = identify ? trace(identify, {
    isVerboseTrace: false,
    name: "identify",
    attributes: { key: definition.key }
  }) : identify;
  flag2.decide = trace(decide, {
    isVerboseTrace: false,
    name: "decide",
    attributes: { key: definition.key }
  });
  flag2.run = trace(run, {
    isVerboseTrace: false,
    name: "run",
    attributes: { key: definition.key }
  });
  return flag2;
}
function getProviderData(flags) {
  const definitions = Object.values(flags).filter((i) => !Array.isArray(i)).reduce((acc, d) => {
    acc[d.key] = {
      options: d.options,
      origin: d.origin,
      description: d.description,
      defaultValue: d.defaultValue,
      declaredInCode: true
    };
    return acc;
  }, {});
  return { definitions, hints: [] };
}
export {
  combine,
  dedupe,
  deserialize2 as deserialize,
  evaluate,
  flag,
  generatePermutations,
  getPrecomputed,
  getProviderData,
  precompute,
  serialize2 as serialize
};
//# sourceMappingURL=next.js.map