refactor: Move default logger to demo app (#1004)

When a logger is not specified as a prop of the entry point Hyperview
component, we currently instantiate a default logger that will emit log
lines to the console. This can causes performance issues for devs that
don't implement a logger, and is noticed in the current demo app.

This PR removes the default logger from core, and implement it
explicitly in the demo app. The default log level in the demo app is set
to `log`, to avoid logging behavior logs, which contribute to a more
sluggish UX.

---------

Co-authored-by: flochtililoch <[email protected]>

demo/App.tsx

@@ -1,9 +1,9 @@
 import './src/gesture-handler';
+import { Logger, fetchWrapper, formatDate } from './src/Helpers';
 import {
   SafeAreaInsetsContext,
   SafeAreaProvider,
 } from 'react-native-safe-area-context';
-import { fetchWrapper, formatDate } from './src/helpers';
 import Behaviors from './src/Behaviors';
 import { BottomTabBar } from './src/Core';
 import { BottomTabBarContextProvider } from './src/Contexts';
@@ -36,6 +36,7 @@ export default () => (
                 entrypointUrl={`${Constants.expoConfig?.extra?.baseUrl}/hyperview/public/index.xml`}
                 fetch={fetchWrapper}
                 formatDate={formatDate}
+                logger={new Logger(Logger.Level.log)}
                 navigationComponents={{
                   BottomTabBar,
                 }}

demo/src/Helpers/index.ts

@@ -0,0 +1,2 @@
+export * from './misc';
+export * from './logger';

demo/src/Helpers/logger.ts

@@ -0,0 +1,62 @@
+// eslint-disable-next-line no-shadow
+enum Level {
+  info = 0,
+  log = 1,
+  warn = 2,
+  error = 3,
+}
+
+const Levels = [Level.info, Level.log, Level.warn, Level.error];
+const LogFunctions = {
+  [Level.info]: console.info,
+  [Level.log]: console.log,
+  [Level.warn]: console.warn,
+  [Level.error]: console.error,
+};
+
+/**
+ * Handles deferredToString objects by calling toString() prior to forwarding to console
+ */
+const convertDeferred = (m?: unknown): string | unknown => {
+  try {
+    return m?.toString();
+  } catch (e) {
+    return m;
+  }
+};
+
+export class Logger {
+  public static Level = Level;
+
+  protected level: number;
+
+  constructor(level: Level) {
+    this.level = Levels.indexOf(level);
+  }
+
+  public log = (m?: unknown, ...p: unknown[]): void => {
+    this.emitter(Level.log, m, ...p);
+  };
+
+  public info = (m?: unknown, ...p: unknown[]): void => {
+    this.emitter(Level.info, m, ...p);
+  };
+
+  public warn = (m?: unknown, ...p: unknown[]): void => {
+    this.emitter(Level.warn, m, ...p);
+  };
+
+  public error = (m?: unknown, ...p: unknown[]): void => {
+    this.emitter(Level.error, m, ...p);
+  };
+
+  protected emitter = (level: Level, m?: unknown, ...p: unknown[]): void => {
+    if (this.level > Levels.indexOf(level)) {
+      return;
+    }
+    LogFunctions[level](
+      convertDeferred(m),
+      p.map(param => convertDeferred(param)),
+    );
+  };
+}

src/services/logging/index.ts

@@ -1,20 +1,19 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
-import { DefaultLogger } from './default-logger';
 import type { Logger } from './types';
 
-let logger: Logger = new DefaultLogger();
+let logger: Logger | null;
 
 export function initialize(loggerInstance: Logger | undefined): void {
   if (loggerInstance) {
     logger = loggerInstance;
   }
 }
 
-export const log = (m?: any, ...p: any[]): void => logger.log(m, ...p);
-export const info = (m?: any, ...p: any[]): void => logger.info(m, ...p);
-export const warn = (m?: any, ...p: any[]): void => logger.warn(m, ...p);
-export const error = (m?: any, ...p: any[]): void => logger.error(m, ...p);
+export const log = (m?: any, ...p: any[]): void => logger?.log(m, ...p);
+export const info = (m?: any, ...p: any[]): void => logger?.info(m, ...p);
+export const warn = (m?: any, ...p: any[]): void => logger?.warn(m, ...p);
+export const error = (m?: any, ...p: any[]): void => logger?.error(m, ...p);
 
 export type { Logger } from './types';
 export { deferredToString } from './tostring-helper';

src/services/logging/tostring-helper.test.ts

@@ -1,10 +1,7 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
-import { DefaultLogger } from './default-logger';
 import { deferredToString } from './tostring-helper';
 
-const logger = new DefaultLogger();
-
 describe('deferredToString', () => {
   describe('with string', () => {
     const helper = deferredToString('foo');
@@ -40,16 +37,6 @@ describe('deferredToString', () => {
       expect(helperSpy).toHaveBeenCalledTimes(1);
       expect(helperVal).toEqual('foo');
     });
-
-    it('does call toString when using custom logger', () => {
-      logger.log('helper', helper);
-      expect(helperSpy).toHaveBeenCalledTimes(1);
-    });
-
-    it('does call toString on each param when using custom logger', () => {
-      logger.log('helper', helper, helper, helper);
-      expect(helperSpy).toHaveBeenCalledTimes(3);
-    });
   });
 
   describe('with func', () => {
@@ -90,15 +77,5 @@ describe('deferredToString', () => {
       expect(expensiveMock).toHaveBeenCalledTimes(1);
       expect(helperVal).toEqual('this was expensive');
     });
-
-    it('does call toString when using custom logger', () => {
-      logger.log('helper', helper);
-      expect(expensiveMock).toHaveBeenCalledTimes(1);
-    });
-
-    it('does call toString on each param when using custom logger', () => {
-      logger.log('helper', helper, helper, helper);
-      expect(expensiveMock).toHaveBeenCalledTimes(3);
-    });
   });
 });