migrate warning mixin to core (elastic#94273)

src/core/server/environment/environment_service.test.ts

@@ -62,18 +62,24 @@ describe('UuidService', () => {
   let logger: ReturnType<typeof loggingSystemMock.create>;
   let configService: ReturnType<typeof configServiceMock.create>;
   let coreContext: CoreContext;
+  let service: EnvironmentService;
 
-  beforeEach(() => {
-    jest.clearAllMocks();
+  beforeEach(async () => {
     logger = loggingSystemMock.create();
     configService = getConfigService();
     coreContext = mockCoreContext.create({ logger, configService });
+
+    service = new EnvironmentService(coreContext);
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
   });
 
   describe('#setup()', () => {
     it('calls resolveInstanceUuid with correct parameters', async () => {
-      const service = new EnvironmentService(coreContext);
       await service.setup();
+
       expect(resolveInstanceUuid).toHaveBeenCalledTimes(1);
       expect(resolveInstanceUuid).toHaveBeenCalledWith({
         pathConfig,
@@ -83,8 +89,8 @@ describe('UuidService', () => {
     });
 
     it('calls createDataFolder with correct parameters', async () => {
-      const service = new EnvironmentService(coreContext);
       await service.setup();
+
       expect(createDataFolder).toHaveBeenCalledTimes(1);
       expect(createDataFolder).toHaveBeenCalledWith({
         pathConfig,
@@ -93,8 +99,8 @@ describe('UuidService', () => {
     });
 
     it('calls writePidFile with correct parameters', async () => {
-      const service = new EnvironmentService(coreContext);
       await service.setup();
+
       expect(writePidFile).toHaveBeenCalledTimes(1);
       expect(writePidFile).toHaveBeenCalledWith({
         pidConfig,
@@ -103,9 +109,31 @@ describe('UuidService', () => {
     });
 
     it('returns the uuid resolved from resolveInstanceUuid', async () => {
-      const service = new EnvironmentService(coreContext);
       const setup = await service.setup();
+
       expect(setup.instanceUuid).toEqual('SOME_UUID');
     });
+
+    describe('process warnings', () => {
+      it('logs warnings coming from the process', async () => {
+        await service.setup();
+
+        const warning = new Error('something went wrong');
+        process.emit('warning', warning);
+
+        expect(logger.get('process').warn).toHaveBeenCalledTimes(1);
+        expect(logger.get('process').warn).toHaveBeenCalledWith(warning);
+      });
+
+      it('does not log deprecation warnings', async () => {
+        await service.setup();
+
+        const warning = new Error('something went wrong');
+        warning.name = 'DeprecationWarning';
+        process.emit('warning', warning);
+
+        expect(logger.get('process').warn).not.toHaveBeenCalled();
+      });
+    });
   });
 });

src/core/server/environment/environment_service.ts

@@ -30,11 +30,13 @@ export interface InternalEnvironmentServiceSetup {
 /** @internal */
 export class EnvironmentService {
   private readonly log: Logger;
+  private readonly processLogger: Logger;
   private readonly configService: IConfigService;
   private uuid: string = '';
 
   constructor(core: CoreContext) {
     this.log = core.logger.get('environment');
+    this.processLogger = core.logger.get('process');
     this.configService = core.configService;
   }
 
@@ -50,6 +52,14 @@ export class EnvironmentService {
       this.log.warn(`Detected an unhandled Promise rejection.\n${reason}`);
     });
 
+    process.on('warning', (warning) => {
+      // deprecation warnings do no reflect a current problem for the user and should be filtered out.
+      if (warning.name === 'DeprecationWarning') {
+        return;
+      }
+      this.processLogger.warn(warning);
+    });
+
     await createDataFolder({ pathConfig, logger: this.log });
     await writePidFile({ pidConfig, logger: this.log });
 

src/legacy/server/kbn_server.js

@@ -15,8 +15,6 @@ import { Config } from './config';
 import httpMixin from './http';
 import { coreMixin } from './core';
 import { loggingMixin } from './logging';
-import warningsMixin from './warnings';
-import configCompleteMixin from './config/complete';
 import { optimizeMixin } from '../../optimize';
 
 /**
@@ -66,10 +64,6 @@ export default class KbnServer {
         coreMixin,
 
         loggingMixin,
-        warningsMixin,
-
-        // tell the config we are done loading plugins
-        configCompleteMixin,
 
         // setup routes that serve the @kbn/optimizer output
         optimizeMixin