@opentelemetry/instrumentation
Version:
Base class for node which OpenTelemetry instrumentation modules extend
107 lines • 4.09 kB
JavaScript
/*
* Copyright The OpenTelemetry Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { Hook } from 'require-in-the-middle';
import * as path from 'path';
import { ModuleNameTrie, ModuleNameSeparator } from './ModuleNameTrie';
/**
* Whether Mocha is running in this process
* Inspired by https://github.com/AndreasPizsa/detect-mocha
*
* @type {boolean}
*/
const isMocha = [
'afterEach',
'after',
'beforeEach',
'before',
'describe',
'it',
].every(fn => {
// @ts-expect-error TS7053: Element implicitly has an 'any' type
return typeof global[fn] === 'function';
});
/**
* Singleton class for `require-in-the-middle`
* Allows instrumentation plugins to patch modules with only a single `require` patch
* WARNING: Because this class will create its own `require-in-the-middle` (RITM) instance,
* we should minimize the number of new instances of this class.
* Multiple instances of `@opentelemetry/instrumentation` (e.g. multiple versions) in a single process
* will result in multiple instances of RITM, which will have an impact
* on the performance of instrumentation hooks being applied.
*/
export class RequireInTheMiddleSingleton {
_moduleNameTrie = new ModuleNameTrie();
static _instance;
constructor() {
this._initialize();
}
_initialize() {
new Hook(
// Intercept all `require` calls; we will filter the matching ones below
null, { internals: true }, (exports, name, basedir) => {
// For internal files on Windows, `name` will use backslash as the path separator
const normalizedModuleName = normalizePathSeparators(name);
const matches = this._moduleNameTrie.search(normalizedModuleName, {
maintainInsertionOrder: true,
// For core modules (e.g. `fs`), do not match on sub-paths (e.g. `fs/promises').
// This matches the behavior of `require-in-the-middle`.
// `basedir` is always `undefined` for core modules.
fullOnly: basedir === undefined,
});
for (const { onRequire } of matches) {
exports = onRequire(exports, name, basedir);
}
return exports;
});
}
/**
* Register a hook with `require-in-the-middle`
*
* @param {string} moduleName Module name
* @param {OnRequireFn} onRequire Hook function
* @returns {Hooked} Registered hook
*/
register(moduleName, onRequire) {
const hooked = { moduleName, onRequire };
this._moduleNameTrie.insert(hooked);
return hooked;
}
/**
* Get the `RequireInTheMiddleSingleton` singleton
*
* @returns {RequireInTheMiddleSingleton} Singleton of `RequireInTheMiddleSingleton`
*/
static getInstance() {
// Mocha runs all test suites in the same process
// This prevents test suites from sharing a singleton
if (isMocha)
return new RequireInTheMiddleSingleton();
return (this._instance =
this._instance ?? new RequireInTheMiddleSingleton());
}
}
/**
* Normalize the path separators to forward slash in a module name or path
*
* @param {string} moduleNameOrPath Module name or path
* @returns {string} Normalized module name or path
*/
function normalizePathSeparators(moduleNameOrPath) {
return path.sep !== ModuleNameSeparator
? moduleNameOrPath.split(path.sep).join(ModuleNameSeparator)
: moduleNameOrPath;
}
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