distinguish browser/webworker usage (#13)

Author: Eskibear

rollup.config.mjs

@@ -16,6 +16,12 @@ export default [
     plugins: [
       typescript({
         compilerOptions: {
+          "lib": [
+            "DOM",
+            "WebWorker",
+            "ESNext"
+          ],
+          "skipDefaultLibCheck": true,
           "module": "ESNext",
           "moduleResolution": "Node",
           "target": "ES2022",

src/AzureAppConfigurationImpl.ts

@@ -9,8 +9,8 @@ import { JsonKeyValueAdapter } from "./JsonKeyValueAdapter";
 import { KeyFilter } from "./KeyFilter";
 import { LabelFilter } from "./LabelFilter";
 import { AzureKeyVaultKeyValueAdapter } from "./keyvault/AzureKeyVaultKeyValueAdapter";
-import { CorrelationContextHeaderName, RequestTracingDisabledEnvironmentVariable } from "./requestTracing/constants";
-import { createCorrelationContextHeader } from "./requestTracing/utils";
+import { CorrelationContextHeaderName } from "./requestTracing/constants";
+import { createCorrelationContextHeader, requestTracingEnabled } from "./requestTracing/utils";
 
 export class AzureAppConfigurationImpl extends Map<string, unknown> implements AzureAppConfiguration {
     private adapters: IKeyValueAdapter[] = [];
@@ -28,11 +28,8 @@ export class AzureAppConfigurationImpl extends Map<string, unknown> implements A
     ) {
         super();
         // Enable request tracing if not opt-out
-        const requestTracingDisabledEnv = process.env[RequestTracingDisabledEnvironmentVariable];
-        if (requestTracingDisabledEnv && requestTracingDisabledEnv.toLowerCase() === "true") {
-            this.requestTracingEnabled = false;
-        } else {
-            this.requestTracingEnabled = true;
+        this.requestTracingEnabled = requestTracingEnabled();
+        if (this.requestTracingEnabled) {
             this.enableRequestTracing();
         }
 

src/requestTracing/constants.ts

@@ -24,7 +24,10 @@ export enum HostType {
     AzureWebApp = "AzureWebApp",
     ContainerApp = "ContainerApp",
     Kubernetes = "Kubernetes",
-    ServiceFabric = "ServiceFabric"
+    ServiceFabric = "ServiceFabric",
+    // Client-side
+    Browser = "Web",
+    WebWorker = "WebWorker"
 }
 
 // Environment variables to identify Host type.

src/requestTracing/utils.ts

@@ -14,6 +14,7 @@ import {
     KubernetesEnvironmentVariable,
     NodeJSDevEnvironmentVariableValue,
     NodeJSEnvironmentVariable,
+    RequestTracingDisabledEnvironmentVariable,
     RequestType,
     RequestTypeKey,
     ServiceFabricEnvironmentVariable
@@ -53,26 +54,65 @@ export function createCorrelationContextHeader(options: AzureAppConfigurationOpt
     return contextParts.join(",");
 }
 
+export function requestTracingEnabled(): boolean {
+    const requestTracingDisabledEnv = getEnvironmentVariable(RequestTracingDisabledEnvironmentVariable);
+    const disabled = requestTracingDisabledEnv?.toLowerCase() === "true";
+    return !disabled;
+}
+
+function getEnvironmentVariable(name: string) {
+    // Make it compatible with non-Node.js runtime
+    if (typeof process?.env === "object") {
+        return process.env[name];
+    } else {
+        return undefined;
+    }
+}
+
 function getHostType(): string | undefined {
     let hostType: string | undefined;
-    if (process.env[AzureFunctionEnvironmentVariable]) {
+    if (getEnvironmentVariable(AzureFunctionEnvironmentVariable)) {
         hostType = HostType.AzureFunction;
-    } else if (process.env[AzureWebAppEnvironmentVariable]) {
+    } else if (getEnvironmentVariable(AzureWebAppEnvironmentVariable)) {
         hostType = HostType.AzureWebApp;
-    } else if (process.env[ContainerAppEnvironmentVariable]) {
+    } else if (getEnvironmentVariable(ContainerAppEnvironmentVariable)) {
         hostType = HostType.ContainerApp;
-    } else if (process.env[KubernetesEnvironmentVariable]) {
+    } else if (getEnvironmentVariable(KubernetesEnvironmentVariable)) {
         hostType = HostType.Kubernetes;
-    } else if (process.env[ServiceFabricEnvironmentVariable]) {
+    } else if (getEnvironmentVariable(ServiceFabricEnvironmentVariable)) {
         hostType = HostType.ServiceFabric;
+    } else if (isBrowser()) {
+        hostType = HostType.Browser;
+    } else if (isWebWorker()) {
+        hostType = HostType.WebWorker;
     }
     return hostType;
 }
 
 function isDevEnvironment(): boolean {
-    const envType = process.env[NodeJSEnvironmentVariable];
+    const envType = getEnvironmentVariable(NodeJSEnvironmentVariable);
     if (NodeJSDevEnvironmentVariableValue === envType?.toLowerCase()) {
         return true;
     }
     return false;
+}
+
+function isBrowser() {
+    // https://developer.mozilla.org/en-US/docs/Web/API/Window
+    const isWindowDefinedAsExpected = typeof window === "object" && typeof Window === "function" && window instanceof Window;
+    // https://developer.mozilla.org/en-US/docs/Web/API/Document
+    const isDocumentDefinedAsExpected = typeof document === "object" && typeof Document === "function" && document instanceof Document;
+
+    return isWindowDefinedAsExpected && isDocumentDefinedAsExpected;
+}
+
+function isWebWorker() {
+    // https://developer.mozilla.org/en-US/docs/Web/API/WorkerGlobalScope
+    const workerGlobalScopeDefined = typeof WorkerGlobalScope !== "undefined";
+    // https://developer.mozilla.org/en-US/docs/Web/API/WorkerNavigator
+    const isNavigatorDefinedAsExpected = typeof navigator === "object" && typeof WorkerNavigator !== "function" && navigator instanceof WorkerNavigator;
+    // https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers#importing_scripts_and_libraries
+    const importScriptsAsGlobalFunction = typeof importScripts === "function";
+
+    return workerGlobalScopeDefined && importScriptsAsGlobalFunction && isNavigatorDefinedAsExpected;
 }

tsconfig.json

@@ -1,5 +1,11 @@
 {
     "compilerOptions": {
+        "lib": [
+            "DOM",
+            "WebWorker",
+            "ESNext"
+        ],
+        "skipDefaultLibCheck": true,
         "module": "ESNext",
         "moduleResolution": "Node",
         "target": "ES2022",