Fb/env log level (#29)

* env log level 1

* env log level 2

* env log level 3

* go with undefined and null as states for Logger.__envMaxLevelNumber

* remove unused variable

Author: rlindner81

src/logger.js

@@ -3,7 +3,7 @@ const util = require("util");
 const VError = require("verror");
 
 const { cfEnv } = require("./env");
-const { tryRequire } = require("./shared/static");
+const { ENV, tryRequire } = require("./shared/static");
 const cds = tryRequire("@sap/cds");
 
 // NOTE: logger levels are tricky. looking at console, npm, winston, and cap there is no real consistency. we will
@@ -87,6 +87,24 @@ const cfAppData = cfEnv.isOnCf
   : undefined;
 
 class Logger {
+  static get envMaxLevelNumber() {
+    if (Logger.__envMaxLevelNumber === undefined) {
+      Logger.__envMaxLevelNumber = null;
+      let envLogLevel = process.env[ENV.LOG_LEVEL]?.trim().toUpperCase();
+      if (envLogLevel) {
+        const level = Object.values(LEVEL).find((level) => level.startsWith(envLogLevel));
+        if (level) {
+          Logger.__envMaxLevelNumber = LEVEL_NUMBER[level];
+        }
+      }
+    }
+    return Logger.__envMaxLevelNumber;
+  }
+
+  static _reset() {
+    Reflect.deleteProperty(Logger, "__envMaxLevelNumber");
+  }
+
   constructor(
     layer = undefined,
     {
@@ -119,7 +137,6 @@ class Logger {
 
   _logData(level, args) {
     let message;
-    let invocationErrorData;
     if (args.length > 0) {
       const firstArg = args[0];
 
@@ -165,15 +182,7 @@ class Logger {
       [FIELD.WRITTEN_TIME]: nowNanos,
       [FIELD.MESSAGE]: message ?? "",
     };
-    return Object.assign(
-      {},
-      cfAppData,
-      ...this.__dataList,
-      invocationErrorData,
-      invocationData,
-      this.__baseData,
-      cdsData
-    );
+    return Object.assign({}, cfAppData, ...this.__dataList, invocationData, this.__baseData, cdsData);
   }
 
   static _readableOutput(data) {
@@ -193,7 +202,13 @@ class Logger {
   }
 
   _log(level, args) {
-    if (this.__maxLevelNumber < LEVEL_NUMBER[level]) {
+    const levelNumber = LEVEL_NUMBER[level];
+    if (
+      (Logger.envMaxLevelNumber !== undefined &&
+        Logger.envMaxLevelNumber !== null &&
+        Logger.envMaxLevelNumber < levelNumber) ||
+      this.__maxLevelNumber < levelNumber
+    ) {
       return;
     }
     const streamOut = level === LEVEL.ERROR ? process.stderr : process.stdout;

src/shared/static.js

@@ -10,6 +10,7 @@ const ENV = Object.freeze({
   UNIQUE_NAME: "BTP_FEATURES_UNIQUE_NAME",
   REDIS_KEY: "BTP_FEATURES_REDIS_KEY",
   REDIS_CHANNEL: "BTP_FEATURES_REDIS_CHANNEL",
+  LOG_LEVEL: "BTP_FEATURES_LOG_LEVEL",
 });
 
 const isNull = (...args) => args.reduce((result, arg) => result || arg === undefined || arg === null, false);

test/logger.test.js

@@ -3,7 +3,8 @@
 const VError = require("verror");
 const featureTogglesModule = require("../src/featureToggles");
 const { FeatureToggles } = featureTogglesModule;
-const { FORMAT, Logger } = require("../src/logger");
+const { ENV } = require("../src/shared/static");
+const { LEVEL, FORMAT, Logger } = require("../src/logger");
 
 const redisWrapperMock = require("../src/redisWrapper");
 jest.mock("../src/redisWrapper", () => require("./__mocks__/redisWrapper"));
@@ -57,6 +58,7 @@ let layer = "/test";
 
 describe("logger test", () => {
   beforeEach(() => {
+    Logger._reset();
     redisWrapperMock._reset();
     envMock._reset();
     featureToggles = new FeatureToggles({ redisKey, redisChannel, refreshMessage });
@@ -181,6 +183,54 @@ caused by: Error: bad validator
       expect(processStreamSpy.stdout.mock.calls.length).toBe(1);
     });
 
+    it("make sure env log level WARN is respected", async () => {
+      process.env[ENV.LOG_LEVEL] = " warn ";
+      logger = new Logger(layer, { maxLevel: LEVEL.TRACE });
+      logger.trace("some trace");
+      logger.debug("some debug");
+      logger.info("some info");
+      expect(processStreamSpy.stdout.mock.calls.length).toBe(0);
+      expect(processStreamSpy.stderr.mock.calls.length).toBe(0);
+      logger.warning("some warning");
+      expect(processStreamSpy.stdout.mock.calls.map(cleanupTextLogCalls)[0]).toMatchInlineSnapshot(`
+[
+  "88:88:88.888 | WARN | /test | some warning",
+]
+`);
+      expect(processStreamSpy.stdout.mock.calls.length).toBe(1);
+      expect(processStreamSpy.stderr.mock.calls.length).toBe(0);
+      processStreamSpy.stdout.mockClear();
+      logger.error("some error");
+      expect(processStreamSpy.stderr.mock.calls.map(cleanupTextLogCalls)[0]).toMatchInlineSnapshot(`
+[
+  "88:88:88.888 | ERROR | /test | some error",
+]
+`);
+      expect(processStreamSpy.stdout.mock.calls.length).toBe(0);
+      expect(processStreamSpy.stderr.mock.calls.length).toBe(1);
+      Reflect.deleteProperty(process.env, ENV.LOG_LEVEL);
+    });
+
+    it("make sure env log level ERROR is respected", async () => {
+      process.env[ENV.LOG_LEVEL] = " err ";
+      logger = new Logger(layer, { maxLevel: LEVEL.TRACE });
+      logger.trace("some trace");
+      logger.debug("some debug");
+      logger.info("some info");
+      logger.warning("some warning");
+      expect(processStreamSpy.stdout.mock.calls.length).toBe(0);
+      expect(processStreamSpy.stderr.mock.calls.length).toBe(0);
+      logger.error("some error");
+      expect(processStreamSpy.stderr.mock.calls.map(cleanupTextLogCalls)[0]).toMatchInlineSnapshot(`
+[
+  "88:88:88.888 | ERROR | /test | some error",
+]
+`);
+      expect(processStreamSpy.stdout.mock.calls.length).toBe(0);
+      expect(processStreamSpy.stderr.mock.calls.length).toBe(1);
+      Reflect.deleteProperty(process.env, ENV.LOG_LEVEL);
+    });
+
     it("error basic usage", async () => {
       logger = new Logger(layer, { format: FORMAT.JSON });
       logger.error(new VError("bla error"));