Implement config validation (#482)

Config was always considered to be valid as `Config.isValid()` just had
a `return true` inside. Now we check the presence of an apiKey in the
configuration data to validate the config.

packages/nodejs/.changesets/config-is-not-considered-valid-anymore-when-apikey-is-missing.md

@@ -0,0 +1,5 @@
+---
+bump: "patch"
+---
+
+The AppSignal config is not considered valid anymore when the apiKey config option is not set.

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

@@ -28,6 +28,12 @@ describe("BaseClient", () => {
     expect(client.isActive).toBeFalsy()
   })
 
+  it("does not start the client if config is not valid", () => {
+    process.env["APPSIGNAL_PUSH_API_KEY"] = undefined
+    client = new BaseClient({ name, enableMinutelyProbes: false })
+    expect(client.isActive).toBeFalsy()
+  })
+
   it("starts the client when the active option is true", () => {
     client = new BaseClient({ ...DEFAULT_OPTS, active: true })
     expect(client.isActive).toBeTruthy()

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

@@ -86,6 +86,28 @@ describe("Configuration", () => {
     })
   })
 
+  describe(".isValid", () => {
+    it("is valid if apiKey is present", () => {
+      expect(config.isValid).toBeTruthy()
+    })
+
+    it("is invalid if apiKey is not present", () => {
+      process.env["APPSIGNAL_PUSH_API_KEY"] = undefined
+      config = new Configuration({ name })
+      expect(config.isValid).toBeFalsy()
+    })
+
+    it("is invalid if apiKey is an empty string", () => {
+      config = new Configuration({ name, apiKey: "" })
+      expect(config.isValid).toBeFalsy()
+    })
+
+    it("is invalid if apiKey is a string with only whitespaces", () => {
+      config = new Configuration({ name, apiKey: "  " })
+      expect(config.isValid).toBeFalsy()
+    })
+  })
+
   describe("Overriden log path with file specified", () => {
     beforeEach(() => {
       process.env["APPSIGNAL_LOG_PATH"] = "/other_path/appsignal.log"

packages/nodejs/src/client.ts

@@ -68,7 +68,7 @@ export class BaseClient implements Client {
     if (this.config.isValid) {
       this.extension.start()
     } else {
-      console.error("Not starting, no valid config for this environment")
+      console.error("Not starting, no valid AppSignal configuration found")
     }
   }
 

packages/nodejs/src/config.ts

@@ -36,11 +36,9 @@ export class Configuration {
 
   /**
    * Returns `true` if the current configuration is valid.
-   *
-   * @todo
    */
   public get isValid(): boolean {
-    return true
+    return (this.data.apiKey || "").trim() !== ""
   }
 
   /**