chore: remove Logger class & refactor Printer (#903)

* chore: remove Logger class & refactor Printer

* fix: update API.md

* fix: update API.md

* fix: update API.md

* fix: make constructor private

* fix: remove yargs & use process.argv

* bump package-lock

* fix: update Printer to be singleton instead of static class

* update changeset

* update API.md

* remove unused imports

* remove unused imports

* fix

* removing no-console linter rule override

* update API.md

* fix test

* .eslintrc

* update integ test

* revert back to stderr

* error logs should write to stderr

* update API.md

* remove printRecord

* remove async

* spread printRecords, updating to singleton

Author: bombguy

.changeset/polite-meals-search.md

@@ -0,0 +1,8 @@
+---
+'create-amplify': minor
+'@aws-amplify/cli-core': minor
+'@aws-amplify/sandbox': minor
+'@aws-amplify/backend-cli': minor
+---
+
+Refactor Printer class & deprecate Logger

package-lock.json

@@ -4,6 +4,8 @@
 
 ```ts
 
+/// <reference types="node" />
+
 // @public
 export class AmplifyPrompter {
     static input: (options: {
@@ -23,12 +25,24 @@ export enum COLOR {
     RED = "31m"
 }
 
+// @public (undocumented)
+export enum LogLevel {
+    // (undocumented)
+    DEBUG = 2,
+    // (undocumented)
+    ERROR = 0,
+    // (undocumented)
+    INFO = 1
+}
+
 // @public
 export class Printer {
-    static print: (message: string, colorName?: COLOR) => void;
-    static printNewLine: () => void;
-    static printRecord: <T extends Record<string | number, RecordValue>>(object: T) => void;
-    static printRecords: <T extends Record<string | number, RecordValue>>(objects: T[]) => void;
+    constructor(minimumLogLevel: LogLevel, stdout?: NodeJS.WriteStream, stderr?: NodeJS.WriteStream, refreshRate?: number);
+    indicateProgress(message: string, callback: () => Promise<void>): Promise<void>;
+    log(message: string, level?: LogLevel, eol?: boolean): void;
+    print: (message: string, colorName?: COLOR) => void;
+    printNewLine: () => void;
+    printRecords: <T extends Record<string | number, RecordValue>>(...objects: T[]) => void;
 }
 
 // @public (undocumented)

packages/cli-core/API.md

@@ -0,0 +1,96 @@
+import { after, before, beforeEach, describe, it, mock } from 'node:test';
+import assert from 'assert';
+import { LogLevel, Printer } from './printer.js';
+
+void describe('Printer', () => {
+  const mockedWrite = mock.method(process.stdout, 'write');
+  let originalWrite: typeof process.stdout.write;
+
+  before(() => {
+    originalWrite = process.stdout.write;
+    process.stdout.write = mockedWrite;
+  });
+
+  after(() => {
+    // restore write function after all tests.
+    process.stdout.write = originalWrite;
+  });
+
+  beforeEach(() => {
+    mockedWrite.mock.resetCalls();
+  });
+
+  void it('log should print message followed by new line', () => {
+    new Printer(LogLevel.INFO).log('hello world');
+    assert.strictEqual(mockedWrite.mock.callCount(), 2);
+    assert.match(
+      mockedWrite.mock.calls[0].arguments[0].toString(),
+      /hello world/
+    );
+    assert.match(mockedWrite.mock.calls[1].arguments[0].toString(), /\n/);
+  });
+
+  void it('log should print message without new line', () => {
+    new Printer(LogLevel.INFO).log('hello world', LogLevel.INFO, false);
+    assert.strictEqual(mockedWrite.mock.callCount(), 1);
+    assert.match(
+      mockedWrite.mock.calls[0].arguments[0].toString(),
+      /hello world/
+    );
+  });
+
+  void it('log should not print debug logs by default', () => {
+    new Printer(LogLevel.INFO).log('hello world', LogLevel.DEBUG);
+    assert.strictEqual(mockedWrite.mock.callCount(), 0);
+  });
+
+  void it('log should print debug logs when printer is configured with minimum log level >= DEBUG', () => {
+    new Printer(LogLevel.DEBUG).log('hello world', LogLevel.DEBUG);
+    assert.strictEqual(mockedWrite.mock.callCount(), 2);
+    assert.match(
+      mockedWrite.mock.calls[0].arguments[0].toString(),
+      /hello world/
+    );
+    assert.match(mockedWrite.mock.calls[1].arguments[0].toString(), /\n/);
+  });
+
+  void it('log should not print debug logs by default', () => {
+    new Printer(LogLevel.INFO).log('hello world', LogLevel.DEBUG);
+    assert.strictEqual(mockedWrite.mock.callCount(), 0);
+  });
+
+  void it('indicateProgress logs message & animates ellipsis if on TTY', async () => {
+    process.stdout.isTTY = true;
+    await new Printer(LogLevel.INFO).indicateProgress(
+      'loading a long list',
+      () => new Promise((resolve) => setTimeout(resolve, 3000))
+    );
+    // filter out the escape characters.
+    const logMessages = mockedWrite.mock.calls
+      .filter((message) =>
+        message.arguments.toString().match(/loading a long list/)
+      )
+      .map((call) => call.arguments.toString());
+
+    logMessages.forEach((message) => {
+      assert.match(message, /loading a long list(.*)/);
+    });
+  });
+
+  void it('indicateProgress does not animates ellipsis if not TTY & prints log message once', async () => {
+    process.stdout.isTTY = false;
+    await new Printer(LogLevel.INFO).indicateProgress(
+      'loading a long list',
+      () => new Promise((resolve) => setTimeout(resolve, 1500))
+    );
+    // filter out the escape characters.
+    const logMessages = mockedWrite.mock.calls
+      .filter((message) =>
+        message.arguments.toString().match(/loading a long list/)
+      )
+      .map((call) => call.arguments.toString());
+
+    assert.strictEqual(logMessages.length, 1);
+    assert.match(logMessages[0], /loading a long list/);
+  });
+});

packages/cli-core/src/printer/.eslintrc.json

@@ -4,49 +4,175 @@ import { EOL } from 'os';
 export type RecordValue = string | number | string[] | Date;
 
 /**
- * The class that pretty prints to the console.
+ * The class that pretty prints to the output stream.
  */
 export class Printer {
+  // Properties for ellipsis animation
+  private timer: ReturnType<typeof setTimeout>;
+  private timerSet: boolean;
+
   /**
-   * Print an object/record to console.
+   * Sets default configs
    */
-  static printRecord = <T extends Record<string | number, RecordValue>>(
-    object: T
-  ): void => {
-    let message = '';
-    const entries = Object.entries(object);
-    entries.forEach(([key, val]) => {
-      message = message.concat(` ${key}: ${val as string}${EOL}`);
-    });
-    console.log(message);
-  };
+  constructor(
+    private readonly minimumLogLevel: LogLevel,
+    private readonly stdout: NodeJS.WriteStream = process.stdout,
+    private readonly stderr: NodeJS.WriteStream = process.stderr,
+    private readonly refreshRate: number = 500
+  ) {}
 
   /**
-   * Prints an array of objects/records to console.
+   * Prints an array of objects/records to output stream.
    */
-  static printRecords = <T extends Record<string | number, RecordValue>>(
-    objects: T[]
+  printRecords = <T extends Record<string | number, RecordValue>>(
+    ...objects: T[]
   ): void => {
     for (const obj of objects) {
       this.printRecord(obj);
     }
   };
 
   /**
-   * Prints a given message (with optional color) to console.
+   * Prints a given message (with optional color) to output stream.
    */
-  static print = (message: string, colorName?: COLOR) => {
+  print = (message: string, colorName?: COLOR) => {
     if (colorName) {
-      console.log(color(colorName, message));
+      this.stdout.write(color(colorName, message));
     } else {
-      console.log(message);
+      this.stdout.write(message);
     }
   };
 
   /**
-   * Prints a new line to console
+   * Logs a message with animated ellipsis
    */
-  static printNewLine = () => {
-    console.log(EOL);
+  async indicateProgress(message: string, callback: () => Promise<void>) {
+    try {
+      this.startAnimatingEllipsis(message);
+      await callback();
+    } finally {
+      this.stopAnimatingEllipsis(message);
+    }
+  }
+
+  /**
+   * Prints a new line to output stream
+   */
+  printNewLine = () => {
+    this.stdout.write(EOL);
   };
+
+  /**
+   * Logs a message to the output stream.
+   */
+  log(message: string, level: LogLevel = LogLevel.INFO, eol = true) {
+    const doLogMessage = level <= this.minimumLogLevel;
+
+    if (!doLogMessage) {
+      return;
+    }
+
+    const logMessage =
+      this.minimumLogLevel === LogLevel.DEBUG
+        ? `[${LogLevel[level]}] ${new Date().toISOString()}: ${message}`
+        : message;
+
+    if (level === LogLevel.ERROR) {
+      this.stderr.write(logMessage);
+    } else {
+      this.stdout.write(logMessage);
+    }
+
+    if (eol) {
+      this.printNewLine();
+    }
+  }
+
+  /**
+   * Print an object/record to output stream.
+   */
+  private printRecord = <T extends Record<string | number, RecordValue>>(
+    object: T
+  ): void => {
+    let message = '';
+    const entries = Object.entries(object);
+    entries.forEach(([key, val]) => {
+      message = message.concat(` ${key}: ${val as string}${EOL}`);
+    });
+    this.stdout.write(message);
+  };
+
+  /**
+   * Start animating ellipsis at the end of a log message.
+   */
+  private startAnimatingEllipsis(message: string) {
+    if (!this.isTTY()) {
+      this.log(message, LogLevel.INFO);
+      return;
+    }
+
+    if (this.timerSet) {
+      throw new Error(
+        'Timer is already set to animate ellipsis, stop the current running timer before starting a new one.'
+      );
+    }
+
+    const frameLength = 4; // number of desired dots - 1
+    let frameCount = 0;
+    this.timerSet = true;
+    this.writeEscapeSequence(EscapeSequence.HIDE_CURSOR);
+    this.stdout.write(message);
+    this.timer = setInterval(() => {
+      this.writeEscapeSequence(EscapeSequence.CLEAR_LINE);
+      this.writeEscapeSequence(EscapeSequence.MOVE_CURSOR_TO_START);
+      this.stdout.write(message + '.'.repeat(++frameCount % frameLength));
+    }, this.refreshRate);
+  }
+
+  /**
+   * Stops animating ellipsis and replace with a log message.
+   */
+  private stopAnimatingEllipsis(message: string) {
+    if (!this.isTTY()) {
+      return;
+    }
+
+    clearInterval(this.timer);
+    this.timerSet = false;
+    this.writeEscapeSequence(EscapeSequence.CLEAR_LINE);
+    this.writeEscapeSequence(EscapeSequence.MOVE_CURSOR_TO_START);
+    this.writeEscapeSequence(EscapeSequence.SHOW_CURSOR);
+    this.stdout.write(`${message}...${EOL}`);
+  }
+
+  /**
+   * Writes escape sequence to stdout
+   */
+  private writeEscapeSequence(action: EscapeSequence) {
+    if (!this.isTTY()) {
+      return;
+    }
+
+    this.stdout.write(action);
+  }
+
+  /**
+   * Checks if the environment is TTY
+   */
+  private isTTY() {
+    return this.stdout.isTTY;
+  }
+}
+
+export enum LogLevel {
+  ERROR = 0,
+  INFO = 1,
+  DEBUG = 2,
+}
+
+enum EscapeSequence {
+  CLEAR_LINE = '\x1b[2K',
+  MOVE_CURSOR_TO_START = '\x1b[0G',
+  SHOW_CURSOR = '\x1b[?25h',
+  HIDE_CURSOR = '\x1b[?25l',
 }

packages/cli-core/src/printer/printer.test.ts

@@ -3,9 +3,10 @@ import yargs, { CommandModule } from 'yargs';
 import { TestCommandRunner } from '../../test-utils/command_runner.js';
 import assert from 'node:assert';
 import { ConfigureProfileCommand } from './configure_profile_command.js';
-import { AmplifyPrompter, Printer } from '@aws-amplify/cli-core';
+import { AmplifyPrompter } from '@aws-amplify/cli-core';
 import { Open } from '../open/open.js';
 import { ProfileController } from './profile_controller.js';
+import { printer } from '../../printer.js';
 
 const testAccessKeyId = 'testAccessKeyId';
 const testSecretAccessKey = 'testSecretAccessKey';
@@ -35,7 +36,7 @@ void describe('configure command', () => {
       'profileExists',
       () => Promise.resolve(true)
     );
-    const mockPrint = contextual.mock.method(Printer, 'print');
+    const mockPrint = contextual.mock.method(printer, 'print');
 
     await commandRunner.runCommand(`profile --name ${testProfile}`);