Move ItemBuffer to package (#196455)

## Summary

Part of https://github.com/elastic/kibana/issues/186139.

Bfetch exports `ItemBuffer` and `TimedItemBuffer`, the latter of which
is also used inside of the content management plugin.

After bfetch is removed, content management will be the sole consumer,
which is why I've added the team ownership to be appex-sharedux.

### Checklist

- [x]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

.github/CODEOWNERS

@@ -541,6 +541,7 @@ x-pack/plugins/observability_solution/investigate @elastic/obs-ux-management-tea
 packages/kbn-investigation-shared @elastic/obs-ux-management-team
 packages/kbn-io-ts-utils @elastic/obs-knowledge-team
 packages/kbn-ipynb @elastic/search-kibana
+packages/kbn-item-buffer @elastic/appex-sharedux
 packages/kbn-jest-serializers @elastic/kibana-operations
 packages/kbn-journeys @elastic/kibana-operations @elastic/appex-qa
 packages/kbn-json-ast @elastic/kibana-operations

package.json

@@ -588,6 +588,7 @@
     "@kbn/investigation-shared": "link:packages/kbn-investigation-shared",
     "@kbn/io-ts-utils": "link:packages/kbn-io-ts-utils",
     "@kbn/ipynb": "link:packages/kbn-ipynb",
+    "@kbn/item-buffer": "link:packages/kbn-item-buffer",
     "@kbn/json-schemas": "link:x-pack/packages/ml/json_schemas",
     "@kbn/kbn-health-gateway-status-plugin": "link:test/health_gateway/plugins/status",
     "@kbn/kbn-sample-panel-action-plugin": "link:test/plugin_functional/plugins/kbn_sample_panel_action",

packages/kbn-item-buffer/README.md

@@ -0,0 +1,4 @@
+# @kbn/item-buffer
+
+`ItemBuffer`: A simple buffer that collects items. Can be cleared or flushed; and can automatically flush when specified number of items is reached.
+`TimedItemBuffer`: An `ItemBuffer` that flushes buffer when oldest item reaches age specified by this parameter, in milliseconds.

packages/kbn-item-buffer/index.ts

@@ -0,0 +1,11 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+export { ItemBuffer, TimedItemBuffer } from './src';
+export type { ItemBufferParams, TimedItemBufferParams } from './src';

packages/kbn-item-buffer/jest.config.js

@@ -0,0 +1,14 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+module.exports = {
+  preset: '@kbn/test/jest_node',
+  rootDir: '../..',
+  roots: ['<rootDir>/packages/kbn-item-buffer'],
+};

packages/kbn-item-buffer/kibana.jsonc

@@ -0,0 +1,5 @@
+{
+  "type": "shared-common",
+  "id": "@kbn/item-buffer",
+  "owner": "@elastic/appex-sharedux"
+}

packages/kbn-item-buffer/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "@kbn/item-buffer",
+  "private": true,
+  "version": "1.0.0",
+  "license": "Elastic License 2.0 OR AGPL-3.0-only OR SSPL-1.0"
+}

packages/kbn-item-buffer/src/index.ts

@@ -0,0 +1,11 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+export * from './item_buffer';
+export * from './timed_item_buffer';

packages/kbn-item-buffer/src/item_buffer.test.ts

@@ -7,7 +7,7 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import { ItemBuffer } from '../item_buffer';
-import { runItemBufferTests } from './run_item_buffer_tests';
+import { ItemBuffer } from './item_buffer';
+import { runItemBufferTests } from './__test__/run_item_buffer_tests';
 
 runItemBufferTests(ItemBuffer);

packages/kbn-item-buffer/src/timed_item_buffer.test.ts

@@ -7,8 +7,8 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import { TimedItemBuffer } from '../timed_item_buffer';
-import { runItemBufferTests } from './run_item_buffer_tests';
+import { TimedItemBuffer } from './timed_item_buffer';
+import { runItemBufferTests } from './__test__/run_item_buffer_tests';
 
 jest.useFakeTimers({ legacyFakeTimers: true });
 

packages/kbn-item-buffer/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "target/types",
+    "types": [
+      "jest",
+      "node"
+    ]
+  },
+  "include": [
+    "**/*.ts",
+  ],
+  "exclude": [
+    "target/**/*"
+  ],
+  "kbn_references": []
+}

src/plugins/bfetch/common/buffer/create_batched_function.test.ts

@@ -7,7 +7,7 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import { createBatchedFunction } from '../create_batched_function';
+import { createBatchedFunction } from './create_batched_function';
 
 describe('createBatchedFunction', () => {
   test('calls onCall every time fn is called, calls onBatch once flushOnMaxItems reached', async () => {

src/plugins/bfetch/common/buffer/create_batched_function.ts

@@ -7,8 +7,8 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import { ItemBufferParams } from './item_buffer';
-import { TimedItemBufferParams, TimedItemBuffer } from './timed_item_buffer';
+import type { ItemBufferParams, TimedItemBufferParams } from '@kbn/item-buffer';
+import { TimedItemBuffer } from '@kbn/item-buffer';
 
 type Fn = (...args: any) => any;
 

src/plugins/bfetch/common/buffer/index.ts

@@ -7,6 +7,4 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-export * from './item_buffer';
-export * from './timed_item_buffer';
 export * from './create_batched_function';

src/plugins/bfetch/common/index.ts

@@ -9,8 +9,7 @@
 
 export { normalizeError, removeLeadingSlash, appendQueryParam } from './util';
 export type { StreamingResponseHandler } from './streaming';
-export type { ItemBufferParams, TimedItemBufferParams, BatchedFunctionParams } from './buffer';
-export { ItemBuffer, TimedItemBuffer, createBatchedFunction } from './buffer';
+export { type BatchedFunctionParams, createBatchedFunction } from './buffer';
 export type { ErrorLike, BatchRequestData, BatchResponseItem, BatchItemWrapper } from './batch';
 export {
   DISABLE_BFETCH_COMPRESSION,

src/plugins/bfetch/public/batching/create_streaming_batched_function.ts

@@ -8,13 +8,8 @@
  */
 
 import { AbortError, abortSignalToPromise, defer } from '@kbn/kibana-utils-plugin/public';
-import {
-  ItemBufferParams,
-  TimedItemBufferParams,
-  createBatchedFunction,
-  ErrorLike,
-  normalizeError,
-} from '../../common';
+import type { ItemBufferParams, TimedItemBufferParams } from '@kbn/item-buffer';
+import { createBatchedFunction, ErrorLike, normalizeError } from '../../common';
 import { fetchStreaming } from '../streaming';
 import { BatchedFunc, BatchItem } from './types';
 

src/plugins/bfetch/tsconfig.json

@@ -13,6 +13,7 @@
     "@kbn/core-http-common",
     "@kbn/bfetch-error",
     "@kbn/ebt-tools",
+    "@kbn/item-buffer",
   ],
   "exclude": [
     "target/**/*",

src/plugins/content_management/server/event_stream/event_stream_service.ts

@@ -8,7 +8,7 @@
  */
 
 import type { CoreSetup } from '@kbn/core/server';
-import { TimedItemBuffer } from '@kbn/bfetch-plugin/common';
+import { TimedItemBuffer } from '@kbn/item-buffer';
 import type {
   EventStreamClient,
   EventStreamClientFactory,

src/plugins/content_management/tsconfig.json

@@ -10,7 +10,7 @@
     "@kbn/core-http-request-handler-context-server",
     "@kbn/es-query",
     "@kbn/core-test-helpers-kbn-server",
-    "@kbn/bfetch-plugin",
+    "@kbn/item-buffer",
     "@kbn/object-versioning",
     "@kbn/core-saved-objects-api-server-mocks",
     "@kbn/core-saved-objects-api-server",

tsconfig.base.json

@@ -1076,6 +1076,8 @@
       "@kbn/io-ts-utils/*": ["packages/kbn-io-ts-utils/*"],
       "@kbn/ipynb": ["packages/kbn-ipynb"],
       "@kbn/ipynb/*": ["packages/kbn-ipynb/*"],
+      "@kbn/item-buffer": ["packages/kbn-item-buffer"],
+      "@kbn/item-buffer/*": ["packages/kbn-item-buffer/*"],
       "@kbn/jest-serializers": ["packages/kbn-jest-serializers"],
       "@kbn/jest-serializers/*": ["packages/kbn-jest-serializers/*"],
       "@kbn/journeys": ["packages/kbn-journeys"],

yarn.lock

@@ -5447,6 +5447,10 @@
   version "0.0.0"
   uid ""
 
+"@kbn/item-buffer@link:packages/kbn-item-buffer":
+  version "0.0.0"
+  uid ""
+
 "@kbn/jest-serializers@link:packages/kbn-jest-serializers":
   version "0.0.0"
   uid ""