1 files changed, 107 insertions, 0 deletions
diff --git a/vanilla/node_modules/undici/lib/interceptor/deduplicate.js b/vanilla/node_modules/undici/lib/interceptor/deduplicate.js
new file mode 100644
index 0000000..11c4f37
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/interceptor/deduplicate.js
@@ -0,0 +1,107 @@
+'use strict'
+
+const diagnosticsChannel = require('node:diagnostics_channel')
+const util = require('../core/util')
+const DeduplicationHandler = require('../handler/deduplication-handler')
+const { normalizeHeaders, makeCacheKey, makeDeduplicationKey } = require('../util/cache.js')
+
+const pendingRequestsChannel = diagnosticsChannel.channel('undici:request:pending-requests')
+
+/**
+ * @param {import('../../types/interceptors.d.ts').default.DeduplicateInterceptorOpts} [opts]
+ * @returns {import('../../types/dispatcher.d.ts').default.DispatcherComposeInterceptor}
+ */
+module.exports = (opts = {}) => {
+  const {
+    methods = ['GET'],
+    skipHeaderNames = [],
+    excludeHeaderNames = []
+  } = opts
+
+  if (typeof opts !== 'object' || opts === null) {
+    throw new TypeError(`expected type of opts to be an Object, got ${opts === null ? 'null' : typeof opts}`)
+  }
+
+  if (!Array.isArray(methods)) {
+    throw new TypeError(`expected opts.methods to be an array, got ${typeof methods}`)
+  }
+
+  for (const method of methods) {
+    if (!util.safeHTTPMethods.includes(method)) {
+      throw new TypeError(`expected opts.methods to only contain safe HTTP methods, got ${method}`)
+    }
+  }
+
+  if (!Array.isArray(skipHeaderNames)) {
+    throw new TypeError(`expected opts.skipHeaderNames to be an array, got ${typeof skipHeaderNames}`)
+  }
+
+  if (!Array.isArray(excludeHeaderNames)) {
+    throw new TypeError(`expected opts.excludeHeaderNames to be an array, got ${typeof excludeHeaderNames}`)
+  }
+
+  // Convert to lowercase Set for case-insensitive header matching
+  const skipHeaderNamesSet = new Set(skipHeaderNames.map(name => name.toLowerCase()))
+
+  // Convert to lowercase Set for case-insensitive header exclusion from deduplication key
+  const excludeHeaderNamesSet = new Set(excludeHeaderNames.map(name => name.toLowerCase()))
+
+  /**
+   * Map of pending requests for deduplication
+   * @type {Map<string, DeduplicationHandler>}
+   */
+  const pendingRequests = new Map()
+
+  return dispatch => {
+    return (opts, handler) => {
+      if (!opts.origin || methods.includes(opts.method) === false) {
+        return dispatch(opts, handler)
+      }
+
+      opts = {
+        ...opts,
+        headers: normalizeHeaders(opts)
+      }
+
+      // Skip deduplication if request contains any of the specified headers
+      if (skipHeaderNamesSet.size > 0) {
+        for (const headerName of Object.keys(opts.headers)) {
+          if (skipHeaderNamesSet.has(headerName.toLowerCase())) {
+            return dispatch(opts, handler)
+          }
+        }
+      }
+
+      const cacheKey = makeCacheKey(opts)
+      const dedupeKey = makeDeduplicationKey(cacheKey, excludeHeaderNamesSet)
+
+      // Check if there's already a pending request for this key
+      const pendingHandler = pendingRequests.get(dedupeKey)
+      if (pendingHandler) {
+        // Add this handler to the waiting list
+        pendingHandler.addWaitingHandler(handler)
+        return true
+      }
+
+      // Create a new deduplication handler
+      const deduplicationHandler = new DeduplicationHandler(
+        handler,
+        () => {
+          // Clean up when request completes
+          pendingRequests.delete(dedupeKey)
+          if (pendingRequestsChannel.hasSubscribers) {
+            pendingRequestsChannel.publish({ size: pendingRequests.size, key: dedupeKey, type: 'removed' })
+          }
+        }
+      )
+
+      // Register the pending request
+      pendingRequests.set(dedupeKey, deduplicationHandler)
+      if (pendingRequestsChannel.hasSubscribers) {
+        pendingRequestsChannel.publish({ size: pendingRequests.size, key: dedupeKey, type: 'added' })
+      }
+
+      return dispatch(opts, deduplicationHandler)
+    }
+  }
+}