feat(compiler-cli): ngcc - make logging more configurable (#29591)

This allows CLI usage to filter excessive log messages
and integrations like webpack plugins to provide their own logger.

// FW-1198

PR Close #29591

packages/compiler-cli/ngcc/src/logging/console_logger.ts

@@ -0,0 +1,46 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {Logger} from './logger';
+
+const RESET = '\x1b[0m';
+const RED = '\x1b[31m';
+const YELLOW = '\x1b[33m';
+const BLUE = '\x1b[36m';
+
+export const DEBUG = `${BLUE}Debug:${RESET}`;
+export const WARN = `${YELLOW}Warning:${RESET}`;
+export const ERROR = `${RED}Error:${RESET}`;
+
+export enum LogLevel {
+  debug,
+  info,
+  warn,
+  error,
+}
+
+/**
+ * A simple logger that outputs directly to the Console.
+ *
+ * The log messages can be filtered based on severity via the `logLevel`
+ * constructor parameter.
+ */
+export class ConsoleLogger implements Logger {
+  constructor(private logLevel: LogLevel) {}
+  debug(...args: string[]) {
+    if (this.logLevel <= LogLevel.debug) console.debug(DEBUG, ...args);
+  }
+  info(...args: string[]) {
+    if (this.logLevel <= LogLevel.info) console.info(...args);
+  }
+  warn(...args: string[]) {
+    if (this.logLevel <= LogLevel.warn) console.warn(WARN, ...args);
+  }
+  error(...args: string[]) {
+    if (this.logLevel <= LogLevel.error) console.error(ERROR, ...args);
+  }
+}

packages/compiler-cli/ngcc/src/logging/logger.ts

@@ -0,0 +1,18 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+ * Implement this interface if you want to provide different logging
+ * output from the standard ConsoleLogger.
+ */
+export interface Logger {
+  debug(...args: string[]): void;
+  info(...args: string[]): void;
+  warn(...args: string[]): void;
+  error(...args: string[]): void;
+}