From 8fc02252d2a0fd18f4bd1ee34b80c7c66cb72c4f Mon Sep 17 00:00:00 2001
From: Ruslan Lopatin <ruslan.lopatin@gmail.com>
Date: Wed, 2 Jun 2021 21:54:50 +0700
Subject: [PATCH] Add trace log level (#2)

---
 README.md                  |  1 +
 src/console-logger.ts      |  5 +++++
 src/console.logger.spec.ts | 27 +++++++++++++++++++++++++++
 src/logger.ts              | 25 +++++++++++++++++--------
 src/silent-logger.spec.ts  |  6 ++++++
 src/silent-logger.ts       |  4 ++++
 6 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index a6b5d89..24720a4 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,7 @@ Logger
 - `warn(...args)` - Logs warning.
 - `info(...args)` - Logs informational message.
 - `debug(...args)` - Logs debug message.
+- `trace(...args)` - Logs tracing message. This may lead to outputting of stack trace.
 
 Each method accepts arbitrary number of arguments.
 
diff --git a/src/console-logger.ts b/src/console-logger.ts
index 6ff2cd5..cdb807c 100644
--- a/src/console-logger.ts
+++ b/src/console-logger.ts
@@ -13,6 +13,7 @@ const consoleLogger$error = (/*#__PURE__*/ consoleLogger$log((...args) => consol
 const consoleLogger$warn = (/*#__PURE__*/ consoleLogger$log((...args) => console.warn(...args)));
 const consoleLogger$info = (/*#__PURE__*/ consoleLogger$log((...args) => console.info(...args)));
 const consoleLogger$debug = (/*#__PURE__*/ consoleLogger$log((...args) => console.debug(...args)));
+const consoleLogger$trace = (/*#__PURE__*/ consoleLogger$log((...args) => console.trace(...args)));
 
 /**
  * Logger instance that logs to console.
@@ -35,4 +36,8 @@ export const consoleLogger: Logger = {
     return consoleLogger$debug;
   },
 
+  get trace() {
+    return consoleLogger$trace;
+  },
+
 };
diff --git a/src/console.logger.spec.ts b/src/console.logger.spec.ts
index 50e2562..e62d139 100644
--- a/src/console.logger.spec.ts
+++ b/src/console.logger.spec.ts
@@ -118,4 +118,31 @@ describe('consoleLogger', () => {
     });
   });
 
+  describe('trace', () => {
+
+    beforeEach(() => {
+      logSpy = jest.spyOn(console, 'trace').mockImplementation(() => { /* do not log */ });
+    });
+
+    it('logs message to console', () => {
+      consoleLogger.trace('message', 1, 2, 3);
+      expect(logSpy).toHaveBeenCalledWith('%s', 'message', 1, 2, 3);
+    });
+    it('logs object to console', () => {
+
+      const object = { name: 'test' };
+
+      consoleLogger.trace(object, 1, 2, 3);
+      expect(logSpy).toHaveBeenCalledWith(object, 1, 2, 3);
+    });
+    it('logs `undefined` to console', () => {
+      consoleLogger.trace(undefined);
+      expect(logSpy).toHaveBeenCalledWith(undefined);
+    });
+    it('logs empty message to console', () => {
+      consoleLogger.trace();
+      expect(logSpy).toHaveBeenCalledWith();
+    });
+  });
+
 });
diff --git a/src/logger.ts b/src/logger.ts
index 8bf9966..9f0d733 100644
--- a/src/logger.ts
+++ b/src/logger.ts
@@ -6,29 +6,38 @@ export interface Logger {
   /**
    * Logs error.
    *
-   * @param args - Log message and arguments.
+   * @param args - Arbitrary arguments to log.
    */
-  error(...args: any[]): void;
+  error(...args: unknown[]): void;
 
   /**
    * Logs warning.
    *
-   * @param args - Log message and arguments.
+   * @param args - Arbitrary arguments to log.
    */
-  warn(...args: any[]): void;
+  warn(...args: unknown[]): void;
 
   /**
    * Logs informational message.
    *
-   * @param args - Log message and arguments.
+   * @param args - Arbitrary arguments to log.
    */
-  info(...args: any[]): void;
+  info(...args: unknown[]): void;
 
   /**
    * Logs debug message.
    *
-   * @param args - Log message and arguments.
+   * @param args - Arbitrary arguments to log.
    */
-  debug(...args: any[]): void;
+  debug(...args: unknown[]): void;
+
+  /**
+   * Logs tracing message.
+   *
+   * This may lead to outputting of stack trace.
+   *
+   * @param args - Arbitrary arguments to log.
+   */
+  trace(...args: unknown[]): void;
 
 }
diff --git a/src/silent-logger.spec.ts b/src/silent-logger.spec.ts
index 2fedf62..c54aa71 100644
--- a/src/silent-logger.spec.ts
+++ b/src/silent-logger.spec.ts
@@ -26,4 +26,10 @@ describe('silentLogger', () => {
       expect(silentLogger.debug).toBe(silentLogger.error);
     });
   });
+
+  describe('trace', () => {
+    it('logs nothing', () => {
+      expect(silentLogger.trace).toBe(silentLogger.error);
+    });
+  });
 });
diff --git a/src/silent-logger.ts b/src/silent-logger.ts
index bc2577f..751428f 100644
--- a/src/silent-logger.ts
+++ b/src/silent-logger.ts
@@ -23,4 +23,8 @@ export const silentLogger: Logger = {
     return silentLogger$log;
   },
 
+  get trace() {
+    return silentLogger$log;
+  },
+
 };