Merge pull request #1 from mratanusarkar/feature/basic-impl

add: basic logger implementation

index.js

@@ -0,0 +1,22 @@
+const logger = require('./logger/logger');
+
+function todo() {
+    try {
+
+        logger.log.silly("This is a silly log.", { category: 'index.js', subcategory: 'todo()' });
+        logger.log.debug("This is a debug log.", { category: 'index.js', subcategory: 'todo()' });
+        logger.log.verbose("This is a verbose log.", { category: 'index.js', subcategory: 'todo()' });
+        logger.log.http("This is a http log.", { category: 'index.js', subcategory: 'todo()' });
+        logger.log.info("This is a info log.", { category: 'index.js', subcategory: 'todo()' });
+        logger.log.warn("This is a warn log.", { category: 'index.js', subcategory: 'todo()' });
+        logger.log.error("This is a error log.", { category: 'index.js', subcategory: 'todo()' });
+
+        let a = mssql.a();
+        console.log("print a:", a); // this line will never work due to error above
+
+    } catch (error) {
+        logger.log.error(error, { category: 'index.js', subcategory: 'todo()' });
+    }
+}
+
+todo();

logger/logger.js

@@ -0,0 +1,48 @@
+const winston = require('winston');
+
+// decide on log level based on environment [dev / qa / staging / prod]
+const environment = 'dev'; // to be added from process.env
+let level = environment === 'prod' ? 'http' : 'silly'
+
+// default meta data
+let project = 'Project Logging'
+let repo = 'NodeJS-Logging-Mechanism'
+let type = 'script'
+let location = 'local runtime'
+
+// output file
+let logDir = './logFiles/';
+let date = new Date().toISOString().split('T')[0];
+let errorFilePath = logDir + date + '-' + 'error.log';
+let comboFilePath = logDir + date + '-' + 'combined.log';
+
+
+/*
+ * Note: Log Levels used as per RFC5424 are:
+ * 0: error
+ * 1: warn
+ * 2: info
+ * 3: http
+ * 4: verbose
+ * 5: debug
+ * 6: silly
+ */
+const log = winston.createLogger({
+    level: level,
+    format: winston.format.combine(
+        winston.format.timestamp(),
+        winston.format.errors({ stack: true }),
+        winston.format.splat(),
+        winston.format.json()
+    ),
+    defaultMeta: { project: project, repo: repo, type: type, location: location },
+    transports: [
+        new winston.transports.File({ filename: errorFilePath, level: 'error' }),
+        new winston.transports.File({ filename: comboFilePath }),
+        // new winston.transports.Console({ format: winston.format.simple() })
+        new winston.transports.Console({ format: winston.format.printf(info => `[${info.timestamp}] (${info.level}): ${info.repo} > ${info.category} > ${info.subcategory} - ${info.message} ${info.stack ? '\n' + info.stack : ''}`) })
+    ]
+});
+
+
+module.exports.log = log;

package.json

@@ -0,0 +1,28 @@
+{
+  "name": "nodejs-logging-mechanism",
+  "version": "1.0.0",
+  "description": "a logging framework for node js applications using winston",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/mratanusarkar/NodeJS-Logging-Mechanism.git"
+  },
+  "keywords": [
+    "log",
+    "logging",
+    "winston",
+    "nodejs"
+  ],
+  "author": "Atanu Sarkar <mratanusarkar@gmail.com> (https://github.com/mratanusarkar)",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/mratanusarkar/NodeJS-Logging-Mechanism/issues"
+  },
+  "homepage": "https://github.com/mratanusarkar/NodeJS-Logging-Mechanism#readme",
+  "dependencies": {
+    "winston": "^3.8.2"
+  }
+}