@web-widget/flags-kit/dist/web-router.js

Flags SDK by Vercel - The feature flags toolkit for Next.js, SvelteKit, and Web Router - Enhanced fork with improved Web Router support

import {
  deserialize,
  memoizeOne,
  normalizeOptions,
  serialize
} from "./chunk-O6VYPARG.js";
import {
  HeadersAdapter,
  RequestCookiesAdapter,
  decryptOverrides,
  internalReportValue,
  reportValue,
  setSpanAttribute,
  trace,
  verifyAccess,
  version
} from "./chunk-BQ2THYCT.js";
import {
  safeJsonStringify
} from "./chunk-2UDLZC33.js";

// src/web-router/index.ts
import { RequestCookies } from "@edge-runtime/cookies";
import { context as context2 } from "@web-widget/context";

// src/web-router/overrides.ts
var memoizedDecrypt = memoizeOne(
  (text) => decryptOverrides(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/web-router/precompute.ts
async function evaluate(flags) {
  return Promise.all(flags.map((flag2) => flag2()));
}
async function precompute(flags) {
  const values = await evaluate(flags);
  const { context: context3 } = await import("@web-widget/context");
  const store = context3().state._flag;
  const secret = store?.secret ?? process.env.FLAGS_SECRET;
  return serialize2(flags, values, secret);
}
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("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("flags: Can not deserialize 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(
      "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(
      "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/web-router/html-transform.ts
function createFlagScriptInjectionTransform(scriptContent) {
  let state = "normal";
  let matchBuffer = "";
  const bodyEndTag = "</body>";
  let injected = false;
  return new TransformStream({
    async transform(chunk, controller) {
      const text = new TextDecoder().decode(chunk);
      let outputBuffer = "";
      let i = 0;
      while (i < text.length) {
        const char = text[i];
        if (state === "normal") {
          if (char === "<") {
            state = "partial_match";
            matchBuffer = char;
          } else {
            outputBuffer += char;
          }
        } else if (state === "partial_match") {
          matchBuffer += char;
          if (bodyEndTag.startsWith(matchBuffer)) {
            if (matchBuffer === bodyEndTag) {
              if (!injected) {
                const content = await scriptContent();
                if (content) {
                  const scriptTag = `<script type="application/json" data-flag-values>${content}</script>`;
                  outputBuffer += scriptTag;
                  injected = true;
                }
              }
              outputBuffer += bodyEndTag;
              state = "normal";
              matchBuffer = "";
            }
          } else {
            const bufferToOutput = matchBuffer.slice(0, -1);
            outputBuffer += bufferToOutput;
            state = "normal";
            matchBuffer = "";
            if (char === "<") {
              state = "partial_match";
              matchBuffer = char;
            } else {
              outputBuffer += char;
            }
          }
        }
        i++;
      }
      if (outputBuffer) {
        controller.enqueue(new TextEncoder().encode(outputBuffer));
      }
    },
    async flush(controller) {
      if (matchBuffer) {
        controller.enqueue(new TextEncoder().encode(matchBuffer));
      }
    }
  });
}

// src/web-router/env.ts
var default_secret = process?.env?.FLAGS_SECRET;
async function tryGetSecret(secret) {
  secret = secret || default_secret;
  if (!secret) {
    throw new Error(
      "flags: No secret provided. Set an environment variable FLAGS_SECRET or provide a secret to the function."
    );
  }
  return secret;
}

// src/web-router/error-handling.ts
async function safeExecute(fn, defaultValue, errorHandler) {
  try {
    return await fn();
  } catch (error) {
    if (errorHandler) {
      errorHandler(error);
    }
    if (defaultValue !== void 0) {
      return defaultValue;
    }
    throw error;
  }
}

// src/web-router/dedupe.ts
import { context } from "@web-widget/context";
function createCacheNode() {
  return {
    s: 0 /* UNTERMINATED */,
    v: void 0,
    o: null,
    p: null
  };
}
var cacheRegistry = /* @__PURE__ */ new WeakMap();
function dedupe(fn) {
  const requestStore = /* @__PURE__ */ new WeakMap();
  const dedupedFn = async function(...args) {
    const store = context().state._flag;
    if (!store?.request) {
      throw new Error(
        "dedupe: No request context found. Make sure dedupe is called within a web-router request handler."
      );
    }
    const request = store.request;
    let cacheNode = requestStore.get(request);
    if (!cacheNode) {
      cacheNode = createCacheNode();
      requestStore.set(request, 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;
    }
  };
  cacheRegistry.set(dedupedFn, requestStore);
  return dedupedFn;
}
function clearDedupeCacheForCurrentRequest(dedupedFn) {
  if (typeof dedupedFn !== "function") {
    throw new Error("dedupe: not a function");
  }
  const requestStore = cacheRegistry.get(dedupedFn);
  if (!requestStore) {
    throw new Error("dedupe: cache not found");
  }
  const store = context().state._flag;
  if (!store?.request) {
    throw new Error(
      "clearDedupeCacheForCurrentRequest: No request context found. Make sure this is called within a web-router request handler."
    );
  }
  return requestStore.delete(store.request);
}

// src/web-router/index.ts
function hasOwnProperty(obj, prop) {
  return obj.hasOwnProperty(prop);
}
var evaluationCache = /* @__PURE__ */ new WeakMap();
var headersMap = /* @__PURE__ */ new WeakMap();
var cookiesMap = /* @__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);
}
function sealHeaders(headers) {
  const cached = headersMap.get(headers);
  if (cached !== void 0)
    return cached;
  const sealed = HeadersAdapter.seal(
    headers,
    "Headers cannot be modified in web-router. Headers are read-only during request processing."
  );
  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),
    "Cookies cannot be modified in web-router. Use Response.headers to set cookies in the response."
  );
  cookiesMap.set(headers, sealed);
  return sealed;
}
async function resolveObjectPromises(obj) {
  const entries = Object.entries(obj);
  const resolvedEntries = await Promise.all(
    entries.map(async ([key, promise]) => {
      const value = await promise;
      return [key, value];
    })
  );
  return Object.fromEntries(resolvedEntries);
}
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(`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 getOrigin(definition) {
  if (definition.origin)
    return definition.origin;
  if (typeof definition.adapter?.origin === "function")
    return definition.adapter.origin(definition.key);
  return definition.adapter?.origin;
}
var requestMap = /* @__PURE__ */ new WeakMap();
function getRun(definition, decide) {
  return async function run(options) {
    let store = context2().state._flag;
    if (!store) {
      if (options.request) {
        const cached = requestMap.get(options.request);
        if (!cached) {
          store = createContext(options.request, await tryGetSecret());
          requestMap.set(options.request, store);
        } else {
          store = cached;
        }
      } else {
        throw new Error("flags: Neither context found nor Request provided");
      }
    }
    const headers = sealHeaders(store.request.headers);
    const cookies = sealCookies(store.request.headers);
    const overridesCookie = cookies.get("vercel-flag-overrides")?.value;
    const overrides = await getOverrides(overridesCookie);
    let entities;
    if (options.identify) {
      if (typeof options.identify === "function") {
        entities = await options.identify({
          headers,
          cookies
        });
      } else {
        entities = options.identify;
      }
    }
    const entitiesKey = JSON.stringify(entities) ?? "";
    const cachedValue = getCachedValuePromise(
      store.request.headers,
      definition.key,
      entitiesKey
    );
    if (cachedValue !== void 0) {
      return await cachedValue;
    }
    if (overrides && hasOwnProperty(overrides, definition.key)) {
      const value2 = overrides[definition.key];
      if (typeof value2 !== "undefined") {
        setSpanAttribute("method", "override");
        const resolvedPromise = Promise.resolve(value2);
        setCachedValuePromise(
          store.request.headers,
          definition.key,
          entitiesKey,
          resolvedPromise
        );
        internalReportValue(definition.key, value2, {
          reason: "override"
        });
        return value2;
      }
    }
    const valuePromise = safeExecute(
      () => decide({
        headers,
        cookies,
        entities
      }),
      definition.defaultValue,
      (error) => {
        if (process.env.NODE_ENV === "development") {
          console.info(
            `flags: Flag "${definition.key}" is falling back to its defaultValue`
          );
        } else {
          console.warn(
            `flags: Flag "${definition.key}" is falling back to its defaultValue after catching the following error`,
            error
          );
        }
      }
    ).then((value2) => {
      if (value2 !== void 0)
        return value2;
      if (definition.defaultValue !== void 0)
        return definition.defaultValue;
      throw new Error(
        `flags: Flag "${definition.key}" must have a defaultValue or a decide function that returns a value`
      );
    });
    setCachedValuePromise(
      store.request.headers,
      definition.key,
      entitiesKey,
      valuePromise
    );
    const value = await valuePromise;
    if (definition.config?.reportValue !== false) {
      reportValue(definition.key, value);
    }
    return value;
  };
}
function flag(definition) {
  const decide = getDecide(definition);
  const identify = getIdentify(definition);
  const run = getRun(definition, decide);
  const origin = getOrigin(definition);
  const flagImpl = trace(
    async function flagImpl2(...args) {
      setSpanAttribute("method", "decided");
      if (typeof args[0] === "string" && Array.isArray(args[1])) {
        setSpanAttribute("method", "precomputed");
        const [precomputedCode, precomputedGroup, secret] = args;
        const effectiveSecret = secret ?? context2().state._flag?.secret ?? await tryGetSecret();
        const tempFlag = { key: definition.key };
        return getPrecomputed(
          tempFlag,
          precomputedGroup,
          precomputedCode,
          effectiveSecret
        );
      }
      let store = context2().state._flag;
      if (!store) {
        if (args[0] instanceof Request) {
          const cached = requestMap.get(args[0]);
          if (!cached) {
            store = createContext(
              args[0],
              args[1] ?? await tryGetSecret()
            );
            requestMap.set(args[0], store);
          } else {
            store = cached;
          }
        } else {
          throw new Error("flags: Neither context found nor Request provided");
        }
      }
      const headers = sealHeaders(store.request.headers);
      const cookies = sealCookies(store.request.headers);
      const overridesCookie = cookies.get("vercel-flag-overrides")?.value;
      const overrides = await getOverrides(overridesCookie);
      let entities;
      if (identify) {
        if (!store.identifiers.has(identify)) {
          const entities2 = identify({
            headers,
            cookies
          });
          store.identifiers.set(identify, entities2);
        }
        entities = await store.identifiers.get(identify);
      }
      const entitiesKey = JSON.stringify(entities) ?? "";
      const cachedValue = getCachedValuePromise(
        store.request.headers,
        definition.key,
        entitiesKey
      );
      if (cachedValue !== void 0) {
        setSpanAttribute("method", "cached");
        const value2 = await cachedValue;
        return value2;
      }
      if (overrides && hasOwnProperty(overrides, definition.key)) {
        const value2 = overrides[definition.key];
        if (typeof value2 !== "undefined") {
          setSpanAttribute("method", "override");
          const resolvedPromise = Promise.resolve(value2);
          store.usedFlags[definition.key] = resolvedPromise;
          setCachedValuePromise(
            store.request.headers,
            definition.key,
            entitiesKey,
            resolvedPromise
          );
          internalReportValue(definition.key, value2, {
            reason: "override"
          });
          return value2;
        }
      }
      const valuePromise = safeExecute(
        () => decide({
          headers,
          cookies,
          entities
        }),
        definition.defaultValue,
        (error) => {
          if (process.env.NODE_ENV === "development") {
            console.info(
              `flags: Flag "${definition.key}" is falling back to its defaultValue`
            );
          } else {
            console.warn(
              `flags: Flag "${definition.key}" is falling back to its defaultValue after catching the following error`,
              error
            );
          }
        }
      ).then((value2) => {
        if (value2 !== void 0)
          return value2;
        if (definition.defaultValue !== void 0)
          return definition.defaultValue;
        throw new Error(
          `flags: Flag "${definition.key}" must have a defaultValue or a decide function that returns a value`
        );
      });
      store.usedFlags[definition.key] = valuePromise;
      setCachedValuePromise(
        store.request.headers,
        definition.key,
        entitiesKey,
        valuePromise
      );
      const value = await valuePromise;
      if (definition.config?.reportValue !== false) {
        reportValue(definition.key, value);
      }
      return value;
    },
    {
      name: "flag",
      isVerboseTrace: false,
      attributes: { key: definition.key }
    }
  );
  flagImpl.key = definition.key;
  flagImpl.defaultValue = definition.defaultValue;
  flagImpl.origin = origin;
  flagImpl.description = definition.description;
  flagImpl.options = normalizeOptions(definition.options);
  flagImpl.decide = trace(decide, {
    isVerboseTrace: false,
    name: "decide",
    attributes: { key: definition.key }
  });
  flagImpl.identify = identify ? trace(identify, {
    isVerboseTrace: false,
    name: "identify",
    attributes: { key: definition.key }
  }) : identify;
  flagImpl.run = trace(run, {
    isVerboseTrace: false,
    name: "run",
    attributes: { key: definition.key }
  });
  return flagImpl;
}
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: [] };
}
function createContext(request, secret, params) {
  return {
    request,
    secret,
    usedFlags: {},
    identifiers: /* @__PURE__ */ new Map()
  };
}
function createHandle({
  secret,
  flags
}) {
  return async function handle({ request, params, render }, next) {
    secret ?? (secret = await tryGetSecret(secret));
    if (flags && // avoid creating the URL object for every request by checking with includes() first
    request.url.includes("/.well-known/") && new URL(request.url).pathname === "/.well-known/vercel/flags") {
      return handleWellKnownFlagsRoute(request.headers, secret, flags);
    }
    if (!render) {
      return next();
    }
    context2().state._flag = createContext(request, secret, params);
    const result = await next();
    if (result && result instanceof Response && result.body) {
      const contentType = result.headers.get("content-type")?.toLowerCase();
      if (contentType && contentType.includes("text/html")) {
        if (isVercelEnvironment()) {
          const transformStream = createFlagScriptInjectionTransform(
            async () => {
              const store = context2().state._flag;
              if (!store || Object.keys(store.usedFlags).length === 0)
                return "";
              const flagValues = await resolveObjectPromises(store.usedFlags);
              const flagsArray = Object.keys(flagValues).map((key) => ({
                key,
                options: void 0
              }));
              const serializedFlagValues = await serialize(
                flagValues,
                flagsArray,
                secret
                // secret is guaranteed to be defined at this point
              );
              return safeJsonStringify(serializedFlagValues);
            }
          );
          const modifiedBody = result.body.pipeThrough(transformStream);
          return new Response(modifiedBody, {
            status: result.status,
            statusText: result.statusText,
            headers: result.headers
          });
        }
      }
    }
    return result;
  };
}
function isVercelEnvironment() {
  return !!(process.env.VERCEL || process.env.VERCEL_ENV);
}
async function handleWellKnownFlagsRoute(headers, secret, flags) {
  const access = await verifyAccess(headers.get("authorization"), secret);
  if (!access)
    return new Response(null, { status: 401 });
  const providerData = getProviderData(flags);
  return Response.json(providerData, {
    headers: { "x-flags-sdk-version": version }
  });
}
function createFlagsDiscoveryEndpoint(getApiData, options) {
  return async (context3) => {
    const access = await verifyAccess(
      context3.request.headers.get("authorization"),
      options?.secret
    );
    if (!access)
      return Response.json(null, { status: 401 });
    const apiData = await getApiData(context3);
    return Response.json(apiData, {
      headers: { "x-flags-sdk-version": version }
    });
  };
}
export {
  clearDedupeCacheForCurrentRequest,
  combine,
  createFlagsDiscoveryEndpoint,
  createHandle,
  dedupe,
  deserialize2 as deserialize,
  evaluate,
  flag,
  generatePermutations,
  getPrecomputed,
  getProviderData,
  precompute,
  serialize2 as serialize
};
//# sourceMappingURL=web-router.js.map