Rename Agent to Extension

To fit with our naming standards, Agent is now called Extension

packages/nodejs/.changesets/rename-agent-to-extension.md

@@ -0,0 +1,7 @@
+---
+bump: "patch"
+---
+
+Rename Agent to Extension
+
+To fit with our naming standards, Agent class is now Called Extension.

packages/nodejs/src/__tests__/data.test.ts

@@ -1,5 +1,5 @@
 import { Data } from "../internal/data"
-import { datamap, dataarray } from "../extension"
+import { datamap, dataarray } from "../extension_wrapper"
 
 describe("Data", () => {
   it("creates an empty map", () => {

packages/nodejs/src/__tests__/agent.test.ts → packages/nodejs/src/__tests__/extension.test.ts

@@ -1,10 +1,10 @@
-import { Agent } from "../agent"
+import { Extension } from "../extension"
 
 describe("Extension", () => {
-  let ext: Agent
+  let ext: Extension
 
   beforeEach(() => {
-    ext = new Agent()
+    ext = new Extension()
   })
 
   afterEach(() => {
@@ -29,7 +29,7 @@ describe("Extension", () => {
 
   it("starts the client when the active option is true", () => {
     expect(() => {
-      ext = new Agent({ active: true })
+      ext = new Extension({ active: true })
     }).not.toThrow()
 
     expect(ext.isLoaded).toBeTruthy()

packages/nodejs/src/client.ts

@@ -1,6 +1,6 @@
 import { NodeClient, Metrics, Plugin, Tracer } from "@appsignal/types"
 
-import { Agent } from "./agent"
+import { Extension } from "./extension"
 import { Configuration } from "./config"
 import { BaseTracer } from "./tracer"
 import { BaseMetrics } from "./metrics"
@@ -24,7 +24,7 @@ export class Client implements NodeClient {
   readonly VERSION = VERSION
 
   config: Configuration
-  agent: Agent
+  extension: Extension
   instrumentation: Instrumentation
 
   #tracer: Tracer = new BaseTracer()
@@ -41,7 +41,7 @@ export class Client implements NodeClient {
     } = options
 
     this.config = new Configuration(options)
-    this.agent = new Agent({ active })
+    this.extension = new Extension({ active })
 
     this.instrumentation = new Instrumentation(this.tracer(), this.metrics())
 
@@ -53,7 +53,7 @@ export class Client implements NodeClient {
    * Returns `true` if the agent is loaded and configuration is valid
    */
   get isActive(): boolean {
-    return this.agent.isLoaded && this.config.isValid
+    return this.extension.isLoaded && this.config.isValid
   }
 
   set isActive(arg) {
@@ -68,7 +68,7 @@ export class Client implements NodeClient {
    */
   public start(): void {
     if (this.config.isValid) {
-      this.agent.start()
+      this.extension.start()
     } else {
       console.error("Not starting, no valid config for this environment")
     }
@@ -87,7 +87,7 @@ export class Client implements NodeClient {
       console.log("Stopping AppSignal")
     }
 
-    this.agent.stop()
+    this.extension.stop()
   }
 
   /**

packages/nodejs/src/diagnose.ts

@@ -4,7 +4,7 @@ import https from "https"
 import { URL, URLSearchParams } from "url"
 import { createHash } from "crypto"
 
-import { Agent } from "./agent"
+import { Extension } from "./extension"
 import { Configuration } from "./config"
 import { AGENT_VERSION, VERSION } from "./version"
 import { JS_TO_RUBY_MAPPING } from "./config/configmap"
@@ -24,11 +24,11 @@ interface FileMetadata {
 
 export class DiagnoseTool {
   #config: Configuration
-  #agent: Agent
+  #extension: Extension
 
   constructor({ active = true }) {
     this.#config = new Configuration({ active })
-    this.#agent = new Agent({ active })
+    this.#extension = new Extension({ active })
   }
 
   /**
@@ -45,7 +45,7 @@ export class DiagnoseTool {
       installation: this.getInstallationReport(),
       host: this.getHostData(),
       app: {},
-      agent: this.#agent.diagnose(),
+      extension: this.#extension.diagnose(),
       config: {
         options: this.getConfigData(),
         sources: {}
@@ -63,7 +63,7 @@ export class DiagnoseTool {
       language: "nodejs",
       package_version: VERSION,
       agent_version: AGENT_VERSION,
-      extension_loaded: this.#agent.isLoaded
+      extension_loaded: this.#extension.isLoaded
     }
   }
 

packages/nodejs/src/extension.ts

@@ -1,20 +1,58 @@
-import { Extension } from "./interfaces/extension"
-
-let mod: Extension
-
-try {
-  mod = require("@appsignal/nodejs-ext") as Extension
-} catch (e) {
-  mod = {
-    extension: {
-      start() {
-        throw new Error("Extension module not loaded")
-      },
-      stop() {
-        return
+import { extension } from "./extension_wrapper"
+
+/**
+ * The public interface for the extension.
+ *
+ * @class
+ */
+export class Extension {
+  isLoaded = false
+
+  constructor(options?: { active: boolean }) {
+    if (options?.active) this.start()
+  }
+
+  /**
+   * Starts the extension.
+   */
+  public start(): boolean {
+    try {
+      extension.start()
+      this.isLoaded = true
+    } catch (e) {
+      if (e.message === "Extension module not loaded") {
+        console.warn(
+          "AppSignal extension not loaded. This could mean that your current environment isn't supported, or that another error has occurred."
+        )
+      } else {
+        console.error(
+          `Failed to load AppSignal extension with error: ${e.message}. Please email us at [email protected] for support.`
+        )
       }
+
+      this.isLoaded = false
     }
-  } as Extension
-}
 
-export = mod
+    return this.isLoaded
+  }
+
+  /**
+   * Stops the extension.
+   */
+  public stop(): boolean {
+    if (this.isLoaded) {
+      extension.stop()
+      this.isLoaded = false
+    }
+
+    return this.isLoaded
+  }
+
+  public diagnose(): object {
+    if (this.isLoaded) {
+      return JSON.parse(extension.diagnoseRaw())
+    } else {
+      return {}
+    }
+  }
+}

packages/nodejs/src/extension_wrapper.ts

@@ -0,0 +1,20 @@
+import { ExtensionWrapper } from "./interfaces/extension_wrapper"
+
+let mod: ExtensionWrapper
+
+try {
+  mod = require("@appsignal/nodejs-ext") as ExtensionWrapper
+} catch (e) {
+  mod = {
+    extension: {
+      start() {
+        throw new Error("Extension module not loaded")
+      },
+      stop() {
+        return
+      }
+    }
+  } as ExtensionWrapper
+}
+
+export = mod

packages/nodejs/src/interfaces/extension_wrapper.ts

@@ -0,0 +1,7 @@
+export interface ExtensionWrapper {
+  extension: any
+  span: any
+  datamap: any
+  dataarray: any
+  metrics: any
+}

packages/nodejs/src/internal/data.ts

@@ -1,5 +1,5 @@
 import { HashMap } from "@appsignal/types"
-import { datamap, dataarray } from "../extension"
+import { datamap, dataarray } from "../extension_wrapper"
 
 export class Data {
   public static generate(

packages/nodejs/src/metrics.ts

@@ -1,7 +1,7 @@
 import { Metrics, Probes } from "@appsignal/types"
 
 import { BaseProbes } from "./probes"
-import { metrics } from "./extension"
+import { metrics } from "./extension_wrapper"
 import { Data } from "./internal/data"
 
 /**

packages/nodejs/src/span.ts

@@ -6,7 +6,7 @@ import {
   HashMapValue
 } from "@appsignal/types"
 
-import { span } from "./extension"
+import { span } from "./extension_wrapper"
 import { Data } from "./internal/data"
 import { getAgentTimestamps } from "./utils"