Consolidate checks that test if the current environment is Node

src/compiler/core.ts

@@ -2914,3 +2914,19 @@ function trimEndImpl(s: string) {
     }
     return s.slice(0, end + 1);
 }
+
+declare const process: any;
+
+/** @internal */
+export function isNodeLikeSystem(): boolean {
+    // This is defined here rather than in sys.ts to prevent a cycle from its
+    // use in performanceCore.ts.
+    //
+    // We don't use the presence of `require` to check if we are in Node;
+    // when bundled using esbuild, this function will be rewritten to `__require`
+    // and definitely exist.
+    return typeof process !== "undefined"
+        && process.nextTick
+        && !process.browser
+        && typeof module === "object";
+}

src/compiler/performanceCore.ts

@@ -1,4 +1,4 @@
-import { Version, VersionRange } from "./_namespaces/ts";
+import { isNodeLikeSystem, Version, VersionRange } from "./_namespaces/ts";
 
 // The following definitions provide the minimum compatible support for the Web Performance User Timings API
 // between browsers and NodeJS:
@@ -80,7 +80,7 @@ function tryGetWebPerformanceHooks(): PerformanceHooks | undefined {
 }
 
 function tryGetNodePerformanceHooks(): PerformanceHooks | undefined {
-    if (typeof process !== "undefined" && process.nextTick && !process.browser && typeof module === "object" && typeof require === "function") {
+    if (isNodeLikeSystem()) {
         try {
             let performance: Performance;
             const { performance: nodePerformance, PerformanceObserver } = require("perf_hooks") as typeof import("perf_hooks");

src/compiler/sys.ts

@@ -2,7 +2,7 @@ import {
     AssertionLevel, closeFileWatcher, closeFileWatcherOf, combinePaths, Comparison, contains, containsPath,
     createGetCanonicalFileName, createMultiMap, Debug, directorySeparator, emptyArray, emptyFileSystemEntries, endsWith,
     enumerateInsertsAndDeletes, ESMap, FileSystemEntries, getDirectoryPath, getFallbackOptions,
-    getNormalizedAbsolutePath, getRelativePathToDirectoryOrUrl, getRootLength, getStringComparer, isArray, isString,
+    getNormalizedAbsolutePath, getRelativePathToDirectoryOrUrl, getRootLength, getStringComparer, isArray, isNodeLikeSystem, isString,
     Map, mapDefined, matchesExclude, matchFiles, memoize, noop, normalizePath, normalizeSlashes, orderedRemoveItem,
     Path, perfLogger, PollingWatchKind, RequireResult, resolveJSModule, some, startsWith, stringContains, timestamp,
     unorderedRemoveItem, WatchDirectoryKind, WatchFileKind, WatchOptions, writeFileEnsuringDirectories,
@@ -1974,9 +1974,7 @@ export let sys: System = (() => {
     }
 
     let sys: System | undefined;
-    if (typeof process !== "undefined" && process.nextTick && !process.browser && typeof require !== "undefined") {
-        // process and process.nextTick checks if current environment is node-like
-        // process.browser check excludes webpack and browserify
+    if (isNodeLikeSystem()) {
         sys = getNodeSystem();
     }
     if (sys) {

src/services/globalThisShim.ts

@@ -1,4 +1,4 @@
-import { TypeScriptServicesFactory, versionMajorMinor } from "./_namespaces/ts";
+import { isNodeLikeSystem, TypeScriptServicesFactory, versionMajorMinor } from "./_namespaces/ts";
 
 // We polyfill `globalThis` here so re can reliably patch the global scope
 // in the contexts we want to in the same way across script and module formats
@@ -47,7 +47,7 @@ declare global {
 
 // if `process` is undefined, we're probably not running in node - patch legacy members onto the global scope
 // @ts-ignore
-if (typeof process === "undefined" || process.browser) {
+if (!isNodeLikeSystem()) {
     /// TODO: this is used by VS, clean this up on both sides of the interface
 
     //@ts-ignore