test: add cache testing suite

docs/docs/api/Dispatcher.md

@@ -1260,6 +1260,8 @@ The `cache` interceptor implements client-side response caching as described in
 
 - `store` - The [`CacheStore`](/docs/docs/api/CacheStore.md) to store and retrieve responses from. Default is [`MemoryCacheStore`](/docs/docs/api/CacheStore.md#memorycachestore).
 - `methods` - The [**safe** HTTP methods](https://www.rfc-editor.org/rfc/rfc9110#section-9.2.1) to cache the response of.
+- `cacheByDefault` - The default expiration time to cache responses by if they don't have an explicit expiration. If this isn't present, responses without explicit expiration will not be cached. Default `undefined`.
+- `type` - The type of cache for Undici to act as. Can be `shared` or `private`. Default `shared`.
 
 ## Instance Events
 

eslint.config.js

@@ -7,6 +7,7 @@ module.exports = [
     ignores: [
       'lib/llhttp',
       'test/fixtures/wpt',
+      'test/fixtures/cache-tests',
       'undici-fetch.js'
     ],
     noJsx: true,

lib/cache/memory-cache-store.js

@@ -89,6 +89,7 @@ class MemoryCacheStore {
           statusCode: entry.statusCode,
           headers: entry.headers,
           body: entry.body,
+          vary: entry.vary ? entry.vary : undefined,
           etag: entry.etag,
           cacheControlDirectives: entry.cacheControlDirectives,
           cachedAt: entry.cachedAt,

lib/cache/sqlite-cache-store.js

@@ -6,6 +6,9 @@ const { assertCacheKey, assertCacheValue } = require('../util/cache.js')
 
 const VERSION = 3
 
+// 2gb
+const MAX_ENTRY_SIZE = 2 * 1000 * 1000 * 1000
+
 /**
  * @typedef {import('../../types/cache-interceptor.d.ts').default.CacheStore} CacheStore
  * @implements {CacheStore}
@@ -18,7 +21,7 @@ const VERSION = 3
  * } & import('../../types/cache-interceptor.d.ts').default.CacheValue} SqliteStoreValue
  */
 module.exports = class SqliteCacheStore {
-  #maxEntrySize = Infinity
+  #maxEntrySize = MAX_ENTRY_SIZE
   #maxCount = Infinity
 
   /**
@@ -78,6 +81,11 @@ module.exports = class SqliteCacheStore {
         ) {
           throw new TypeError('SqliteCacheStore options.maxEntrySize must be a non-negative integer')
         }
+
+        if (opts.maxEntrySize > MAX_ENTRY_SIZE) {
+          throw new TypeError('SqliteCacheStore options.maxEntrySize must be less than 2gb')
+        }
+
         this.#maxEntrySize = opts.maxEntrySize
       }
 
@@ -227,6 +235,7 @@ module.exports = class SqliteCacheStore {
       statusMessage: value.statusMessage,
       headers: value.headers ? JSON.parse(value.headers) : undefined,
       etag: value.etag ? value.etag : undefined,
+      vary: value.vary ?? undefined,
       cacheControlDirectives: value.cacheControlDirectives
         ? JSON.parse(value.cacheControlDirectives)
         : undefined,
@@ -394,10 +403,10 @@ module.exports = class SqliteCacheStore {
           return undefined
         }
 
-        const vary = JSON.parse(value.vary)
+        value.vary = JSON.parse(value.vary)
 
-        for (const header in vary) {
-          if (!headerValueEquals(headers[header], vary[header])) {
+        for (const header in value.vary) {
+          if (!headerValueEquals(headers[header], value.vary[header])) {
             matches = false
             break
           }

lib/handler/cache-handler.js

@@ -10,14 +10,26 @@ const {
 function noop () {}
 
 /**
- * @implements {import('../../types/dispatcher.d.ts').default.DispatchHandler}
+ * @typedef {import('../../types/dispatcher.d.ts').default.DispatchHandler} DispatchHandler
+ *
+ * @implements {DispatchHandler}
  */
 class CacheHandler {
   /**
    * @type {import('../../types/cache-interceptor.d.ts').default.CacheKey}
    */
   #cacheKey
 
+  /**
+   * @type {import('../../types/cache-interceptor.d.ts').default.CacheHandlerOptions['type']}
+   */
+  #cacheType
+
+  /**
+   * @type {number | undefined}
+   */
+  #cacheByDefault
+
   /**
    * @type {import('../../types/cache-interceptor.d.ts').default.CacheStore}
    */
@@ -38,8 +50,10 @@ class CacheHandler {
    * @param {import('../../types/cache-interceptor.d.ts').default.CacheKey} cacheKey
    * @param {import('../../types/dispatcher.d.ts').default.DispatchHandler} handler
    */
-  constructor ({ store }, cacheKey, handler) {
+  constructor ({ store, type, cacheByDefault }, cacheKey, handler) {
     this.#store = store
+    this.#cacheType = type
+    this.#cacheByDefault = cacheByDefault
     this.#cacheKey = cacheKey
     this.#handler = handler
   }
@@ -83,24 +97,47 @@ class CacheHandler {
     }
 
     const cacheControlHeader = headers['cache-control']
-    if (!cacheControlHeader) {
+    if (!cacheControlHeader && !headers['expires'] && !this.#cacheByDefault) {
       // Don't have the cache control header or the cache is full
       return downstreamOnHeaders()
     }
 
-    const cacheControlDirectives = parseCacheControlHeader(cacheControlHeader)
-    if (!canCacheResponse(statusCode, headers, cacheControlDirectives)) {
+    const cacheControlDirectives = cacheControlHeader ? parseCacheControlHeader(cacheControlHeader) : {}
+    if (!canCacheResponse(this.#cacheType, statusCode, headers, cacheControlDirectives)) {
       return downstreamOnHeaders()
     }
 
+    const age = getAge(headers)
+
     const now = Date.now()
-    const staleAt = determineStaleAt(now, headers, cacheControlDirectives)
+    const staleAt = determineStaleAt(this.#cacheType, now, headers, cacheControlDirectives) ?? this.#cacheByDefault
     if (staleAt) {
-      const varyDirectives = this.#cacheKey.headers && headers.vary
-        ? parseVaryHeader(headers.vary, this.#cacheKey.headers)
-        : undefined
-      const deleteAt = determineDeleteAt(now, cacheControlDirectives, staleAt)
+      let baseTime = now
+      if (headers['date']) {
+        const parsedDate = parseInt(headers['date'])
+        const date = new Date(isNaN(parsedDate) ? headers['date'] : parsedDate)
+        if (date instanceof Date && !isNaN(date)) {
+          baseTime = date.getTime()
+        }
+      }
+
+      const absoluteStaleAt = staleAt + baseTime
+
+      if (now >= absoluteStaleAt || (age && age >= staleAt)) {
+        // Response is already stale
+        return downstreamOnHeaders()
+      }
+
+      let varyDirectives
+      if (this.#cacheKey.headers && headers.vary) {
+        varyDirectives = parseVaryHeader(headers.vary, this.#cacheKey.headers)
+        if (!varyDirectives) {
+          // Parse error
+          return downstreamOnHeaders()
+        }
+      }
 
+      const deleteAt = determineDeleteAt(cacheControlDirectives, absoluteStaleAt)
       const strippedHeaders = stripNecessaryHeaders(headers, cacheControlDirectives)
 
       /**
@@ -112,8 +149,8 @@ class CacheHandler {
         headers: strippedHeaders,
         vary: varyDirectives,
         cacheControlDirectives,
-        cachedAt: now,
-        staleAt,
+        cachedAt: age ? now - (age * 1000) : now,
+        staleAt: absoluteStaleAt,
         deleteAt
       }
 
@@ -129,6 +166,7 @@ class CacheHandler {
           .on('drain', () => controller.resume())
           .on('error', function () {
             // TODO (fix): Make error somehow observable?
+            handler.#writeStream = undefined
           })
           .on('close', function () {
             if (handler.#writeStream === this) {
@@ -167,25 +205,29 @@ class CacheHandler {
 /**
  * @see https://www.rfc-editor.org/rfc/rfc9111.html#name-storing-responses-to-authen
  *
+ * @param {import('../../types/cache-interceptor.d.ts').default.CacheOptions['type']} cacheType
  * @param {number} statusCode
  * @param {Record<string, string | string[]>} headers
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives} cacheControlDirectives
  */
-function canCacheResponse (statusCode, headers, cacheControlDirectives) {
+function canCacheResponse (cacheType, statusCode, headers, cacheControlDirectives) {
   if (statusCode !== 200 && statusCode !== 307) {
     return false
   }
 
   if (
-    cacheControlDirectives.private === true ||
     cacheControlDirectives['no-cache'] === true ||
     cacheControlDirectives['no-store']
   ) {
     return false
   }
 
+  if (cacheType === 'shared' && cacheControlDirectives.private === true) {
+    return false
+  }
+
   // https://www.rfc-editor.org/rfc/rfc9111.html#section-4.1-5
-  if (headers.vary === '*') {
+  if (headers.vary?.includes('*')) {
     return false
   }
 
@@ -214,60 +256,88 @@ function canCacheResponse (statusCode, headers, cacheControlDirectives) {
 }
 
 /**
+ * @param {Record<string, string | string[]>} headers
+ * @returns {number | undefined}
+ */
+function getAge (headers) {
+  if (!headers.age) {
+    return undefined
+  }
+
+  const age = parseInt(Array.isArray(headers.age) ? headers.age[0] : headers.age)
+  if (isNaN(age) || age >= 2147483647) {
+    return undefined
+  }
+
+  return age
+}
+
+/**
+ * @param {import('../../types/cache-interceptor.d.ts').default.CacheOptions['type']} cacheType
  * @param {number} now
  * @param {Record<string, string | string[]>} headers
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives} cacheControlDirectives
  *
  * @returns {number | undefined} time that the value is stale at or undefined if it shouldn't be cached
  */
-function determineStaleAt (now, headers, cacheControlDirectives) {
-  // Prioritize s-maxage since we're a shared cache
-  //  s-maxage > max-age > Expire
-  //  https://www.rfc-editor.org/rfc/rfc9111.html#section-5.2.2.10-3
-  const sMaxAge = cacheControlDirectives['s-maxage']
-  if (sMaxAge) {
-    return now + (sMaxAge * 1000)
-  }
-
-  if (cacheControlDirectives.immutable) {
-    // https://www.rfc-editor.org/rfc/rfc8246.html#section-2.2
-    return now + 31536000
+function determineStaleAt (cacheType, now, headers, cacheControlDirectives) {
+  if (cacheType === 'shared') {
+    // Prioritize s-maxage since we're a shared cache
+    //  s-maxage > max-age > Expire
+    //  https://www.rfc-editor.org/rfc/rfc9111.html#section-5.2.2.10-3
+    const sMaxAge = cacheControlDirectives['s-maxage']
+    if (sMaxAge) {
+      return sMaxAge * 1000
+    }
   }
 
   const maxAge = cacheControlDirectives['max-age']
   if (maxAge) {
-    return now + (maxAge * 1000)
+    return maxAge * 1000
   }
 
-  if (headers.expire && typeof headers.expire === 'string') {
+  if (headers.expires && typeof headers.expires === 'string') {
     // https://www.rfc-editor.org/rfc/rfc9111.html#section-5.3
-    const expiresDate = new Date(headers.expire)
+    const expiresDate = new Date(headers.expires)
     if (expiresDate instanceof Date && Number.isFinite(expiresDate.valueOf())) {
-      return now + (Date.now() - expiresDate.getTime())
+      if (now >= expiresDate.getTime()) {
+        return undefined
+      }
+
+      return expiresDate.getTime() - now
     }
   }
 
+  if (cacheControlDirectives.immutable) {
+    // https://www.rfc-editor.org/rfc/rfc8246.html#section-2.2
+    return 31536000
+  }
+
   return undefined
 }
 
 /**
- * @param {number} now
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives} cacheControlDirectives
  * @param {number} staleAt
  */
-function determineDeleteAt (now, cacheControlDirectives, staleAt) {
+function determineDeleteAt (cacheControlDirectives, staleAt) {
   let staleWhileRevalidate = -Infinity
   let staleIfError = -Infinity
+  let immutable = -Infinity
 
   if (cacheControlDirectives['stale-while-revalidate']) {
-    staleWhileRevalidate = now + (cacheControlDirectives['stale-while-revalidate'] * 1000)
+    staleWhileRevalidate = staleAt + (cacheControlDirectives['stale-while-revalidate'] * 1000)
   }
 
   if (cacheControlDirectives['stale-if-error']) {
-    staleIfError = now + (cacheControlDirectives['stale-if-error'] * 1000)
+    staleIfError = staleAt + (cacheControlDirectives['stale-if-error'] * 1000)
   }
 
-  return Math.max(staleAt, staleWhileRevalidate, staleIfError)
+  if (staleWhileRevalidate === -Infinity && staleIfError === -Infinity) {
+    immutable = 31536000
+  }
+
+  return Math.max(staleAt, staleWhileRevalidate, staleIfError, immutable)
 }
 
 /**
@@ -277,7 +347,29 @@ function determineDeleteAt (now, cacheControlDirectives, staleAt) {
  * @returns {Record<string, string | string []>}
  */
 function stripNecessaryHeaders (headers, cacheControlDirectives) {
-  const headersToRemove = ['connection']
+  const headersToRemove = [
+    'connection',
+    'proxy-authenticate',
+    'proxy-authentication-info',
+    'proxy-authorization',
+    'proxy-connection',
+    'te',
+    'transfer-encoding',
+    'upgrade',
+    // We'll add age back when serving it
+    'age'
+  ]
+
+  if (headers['connection']) {
+    if (Array.isArray(headers['connection'])) {
+      // connection: a
+      // connection: b
+      headersToRemove.push(...headers['connection'].map(header => header.trim()))
+    } else {
+      // connection: a, b
+      headersToRemove.push(...headers['connection'].split(',').map(header => header.trim()))
+    }
+  }
 
   if (Array.isArray(cacheControlDirectives['no-cache'])) {
     headersToRemove.push(...cacheControlDirectives['no-cache'])
@@ -288,12 +380,13 @@ function stripNecessaryHeaders (headers, cacheControlDirectives) {
   }
 
   let strippedHeaders
-  for (const headerName of Object.keys(headers)) {
-    if (headersToRemove.includes(headerName)) {
+  for (const headerName of headersToRemove) {
+    if (headers[headerName]) {
       strippedHeaders ??= { ...headers }
-      delete headers[headerName]
+      delete strippedHeaders[headerName]
     }
   }
+
   return strippedHeaders ?? headers
 }