std/log - Expose Logger type and improve public interface for get & set log levels (#6617)

3 files changed, 166 insertions, 13 deletions

diff --git a/std/log/logger.ts b/std/log/logger.ts
index 004088d9a..05e83dc77 100644
--- a/std/log/logger.ts
+++ b/std/log/logger.ts
@@ -43,22 +43,43 @@ export interface LoggerOptions {
 }
 
 export class Logger {
-  level: number;
-  levelName: LevelName;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  handlers: any[];
-  loggerName: string;
+  #level: LogLevels;
+  #handlers: BaseHandler[];
+  readonly #loggerName: string;
 
   constructor(
     loggerName: string,
     levelName: LevelName,
     options: LoggerOptions = {}
   ) {
-    this.loggerName = loggerName;
-    this.level = getLevelByName(levelName);
-    this.levelName = levelName;
+    this.#loggerName = loggerName;
+    this.#level = getLevelByName(levelName);
+    this.#handlers = options.handlers || [];
+  }
+
+  get level(): LogLevels {
+    return this.#level;
+  }
+  set level(level: LogLevels) {
+    this.#level = level;
+  }
 
-    this.handlers = options.handlers || [];
+  get levelName(): LevelName {
+    return getLevelName(this.#level);
+  }
+  set levelName(levelName: LevelName) {
+    this.#level = getLevelByName(levelName);
+  }
+
+  get loggerName(): string {
+    return this.#loggerName;
+  }
+
+  set handlers(hndls: BaseHandler[]) {
+    this.#handlers = hndls;
+  }
+  get handlers(): BaseHandler[] {
+    return this.#handlers;
   }
 
   /** If the level of the logger is greater than the level to log, then nothing
@@ -68,7 +89,7 @@ export class Logger {
    * function, not the function itself, unless the function isn't called, in which
    * case undefined is returned.  All types are coerced to strings for logging.
    */
-  _log<T>(
+  private _log<T>(
     level: number,
     msg: (T extends Function ? never : T) | (() => T),
     ...args: unknown[]
@@ -92,7 +113,7 @@ export class Logger {
       loggerName: this.loggerName,
     });
 
-    this.handlers.forEach((handler): void => {
+    this.#handlers.forEach((handler): void => {
       handler.handle(record);
     });
 
diff --git a/std/log/mod.ts b/std/log/mod.ts
index a1a863d4a..ed94725c4 100644
--- a/std/log/mod.ts
+++ b/std/log/mod.ts
@@ -10,7 +10,8 @@ import {
 import { assert } from "../_util/assert.ts";
 import { LevelName } from "./levels.ts";
 
-export { LogLevels } from "./levels.ts";
+export { LogLevels, LevelName } from "./levels.ts";
+export { Logger } from "./logger.ts";
 
 export class LoggerConfig {
   level?: LevelName;
diff --git a/std/log/mod_test.ts b/std/log/mod_test.ts
index 9de5d76af..30c6b0914 100644
--- a/std/log/mod_test.ts
+++ b/std/log/mod_test.ts
@@ -8,8 +8,10 @@ import {
   error,
   critical,
   setup,
+  Logger,
+  LogLevels,
+  LevelName,
 } from "./mod.ts";
-import { Logger } from "./logger.ts";
 import { BaseHandler } from "./handlers.ts";
 
 class TestHandler extends BaseHandler {
@@ -89,3 +91,132 @@ Deno.test({
     assertEquals(anotherConsoleHandler.messages[0], "[tasks] ERROR world");
   },
 });
+
+Deno.test({
+  name: "Loggers have level and levelName to get/set loglevels",
+  async fn() {
+    const testHandler = new TestHandler("DEBUG");
+    await setup({
+      handlers: {
+        test: testHandler,
+      },
+
+      loggers: {
+        // configure default logger available via short-hand methods above
+        default: {
+          level: "DEBUG",
+          handlers: ["test"],
+        },
+      },
+    });
+    const logger: Logger = getLogger();
+    assertEquals(logger.levelName, "DEBUG");
+    assertEquals(logger.level, LogLevels.DEBUG);
+
+    logger.debug("debug");
+    logger.error("error");
+    logger.critical("critical");
+    assertEquals(testHandler.messages.length, 3);
+    assertEquals(testHandler.messages[0], "DEBUG debug");
+    assertEquals(testHandler.messages[1], "ERROR error");
+    assertEquals(testHandler.messages[2], "CRITICAL critical");
+
+    testHandler.messages = [];
+    logger.level = LogLevels.WARNING;
+    assertEquals(logger.levelName, "WARNING");
+    assertEquals(logger.level, LogLevels.WARNING);
+
+    logger.debug("debug2");
+    logger.error("error2");
+    logger.critical("critical2");
+    assertEquals(testHandler.messages.length, 2);
+    assertEquals(testHandler.messages[0], "ERROR error2");
+    assertEquals(testHandler.messages[1], "CRITICAL critical2");
+
+    testHandler.messages = [];
+    const setLevelName: LevelName = "CRITICAL";
+    logger.levelName = setLevelName;
+    assertEquals(logger.levelName, "CRITICAL");
+    assertEquals(logger.level, LogLevels.CRITICAL);
+
+    logger.debug("debug3");
+    logger.error("error3");
+    logger.critical("critical3");
+    assertEquals(testHandler.messages.length, 1);
+    assertEquals(testHandler.messages[0], "CRITICAL critical3");
+  },
+});
+
+Deno.test({
+  name: "Loggers have loggerName to get logger name",
+  async fn() {
+    const testHandler = new TestHandler("DEBUG");
+    await setup({
+      handlers: {
+        test: testHandler,
+      },
+
+      loggers: {
+        namedA: {
+          level: "DEBUG",
+          handlers: ["test"],
+        },
+        namedB: {
+          level: "DEBUG",
+          handlers: ["test"],
+        },
+      },
+    });
+
+    assertEquals(getLogger("namedA").loggerName, "namedA");
+    assertEquals(getLogger("namedB").loggerName, "namedB");
+    assertEquals(getLogger().loggerName, "default");
+    assertEquals(getLogger("nonsetupname").loggerName, "nonsetupname");
+  },
+});
+
+Deno.test({
+  name: "Logger has mutable handlers",
+  async fn() {
+    const testHandlerA = new TestHandler("DEBUG");
+    const testHandlerB = new TestHandler("DEBUG");
+    await setup({
+      handlers: {
+        testA: testHandlerA,
+        testB: testHandlerB,
+      },
+
+      loggers: {
+        default: {
+          level: "DEBUG",
+          handlers: ["testA"],
+        },
+      },
+    });
+    const logger: Logger = getLogger();
+    logger.info("msg1");
+    assertEquals(testHandlerA.messages.length, 1);
+    assertEquals(testHandlerA.messages[0], "INFO msg1");
+    assertEquals(testHandlerB.messages.length, 0);
+
+    logger.handlers = [testHandlerA, testHandlerB];
+
+    logger.info("msg2");
+    assertEquals(testHandlerA.messages.length, 2);
+    assertEquals(testHandlerA.messages[1], "INFO msg2");
+    assertEquals(testHandlerB.messages.length, 1);
+    assertEquals(testHandlerB.messages[0], "INFO msg2");
+
+    logger.handlers = [testHandlerB];
+
+    logger.info("msg3");
+    assertEquals(testHandlerA.messages.length, 2);
+    assertEquals(testHandlerB.messages.length, 2);
+    assertEquals(testHandlerB.messages[1], "INFO msg3");
+
+    logger.handlers = [];
+    logger.info("msg4");
+    assertEquals(testHandlerA.messages.length, 2);
+    assertEquals(testHandlerB.messages.length, 2);
+  },
+});