feat: not applicable syslog levels

BREAKING CHANGE:
'critical', 'alert' and 'emergency' levels were dropped as seem to
not serve a use case in context of JS apps

README.md

@@ -46,16 +46,16 @@ log.error("error message to be logged");
 
 #### Available log levels
 
-Mirror of syslog (in severity order):
+Mirror of applicable syslog levels (in severity order):
 
--   `debug` - debugging information
--   `info` - a purely informational message
+-   `debug` - debugging information (hidden by default)
+-   `info` - a purely informational message (hidden by default)
 -   `notice` - condition normal, but significant
 -   `warning` (also aliased as `warn`) - condition warning
--   `error` - condition error
--   `critical` - condition critical
--   `alert` - immediate action required
--   `emergency` - system unusable
+-   `error` - condition error - to notify of errors accompanied with recovery mechanism (hence reported as log and not as uncaught exception)
+
+_Note: `critical`, `alert`, `emergency` are not exposed as seem to not serve a use case in context of JS applications,
+such errors should be exposed as typical exceptions_
 
 #### Output message formatting
 

levels.json

@@ -1 +1 @@
-["debug", "info", "notice", "warning", "error", "critical", "alert", "emergency"]
+["debug", "info", "notice", "warning", "error"]

lib/level-symbols.json

@@ -1,10 +1 @@
-{
-    "debug": "●",
-    "info": "ℹ",
-    "notice": "ℹ",
-    "warning": "⚠",
-    "error": "✖",
-    "critical": "✖",
-    "alert": "✖",
-    "emergency": "✖"
-}
+{ "debug": "●", "info": "ℹ", "notice": "ℹ", "warning": "⚠", "error": "✖" }

test/index/01-index.js

@@ -72,9 +72,6 @@ test("(main)", function (t) {
 		t.equal(typeof log.notice, "function");
 		t.equal(typeof log.warning, "function");
 		t.equal(typeof log.error, "function");
-		t.equal(typeof log.critical, "function");
-		t.equal(typeof log.alert, "function");
-		t.equal(typeof log.emergency, "function");
 		t.end();
 	});
 

test/index/04-events.js

@@ -72,7 +72,7 @@ test("(main): Events", function (t) {
 		t.test("new level logger instance is created", function (t) {
 			var currentLog, caughtEvent;
 			emitter.once("init", function (event) { caughtEvent = event; });
-			currentLog = log.critical;
+			currentLog = log.warn;
 			t.equal(caughtEvent.logger, currentLog, "Event should expose initialized logger");
 			t.end();
 		});

test/lib/setup-visibility/02-existing.js

@@ -22,15 +22,13 @@ test("lib: setupVisibility: Affects already created loggers", function (t) {
 	log.debug.get("e1:d");
 	log.warning.get("e2:e");
 	log.error.get("foo");
-	log.alert.get("foo");
 	log.warning.get("e1");
 
 	setupEnv("error", ["e1", "-e1:d", "n1:d", "-n1:d:foo:*"]);
 
 	t.equal(log.debug.isEnabled, false, "Disables level logger deep below level threshold");
 	t.equal(log.warning.isEnabled, false, "Disables level logger just below threshold");
 	t.equal(log.error.isEnabled, true, "Keeps logger at the threshold enabled");
-	t.equal(log.alert.isEnabled, true, "Keeps loggers above threshold enabled");
 
 	t.test("Applies debug namespace map for level loggers below threshold", function (t) {
 		t.equal(log.warning.get("e1").isEnabled, true, "Enables directly mentioned namespace");

test/lib/setup-visibility/03-future.js

@@ -22,13 +22,11 @@ test("lib: setupVisibility: Affects loggers created later", function (t) {
 	log.debug.get("e1:d");
 	log.warning.get("e2:e");
 	log.error.get("foo");
-	log.alert.get("foo");
 	log.warning.get("e1");
 
 	setupEnv("error", ["e1", "-e1:d", "n1:d", "-n1:d:foo:*"]);
 
 	t.equal(log.info.isEnabled, false, "Disables level logger deep below level threshold");
-	t.equal(log.critical.isEnabled, true, "Keeps loggers above threshold enabled");
 
 	t.test("Applies debug namespace map for level loggers below threshold", function (t) {
 		t.equal(log.info.get("e1").isEnabled, true, "Enables directly mentioned namespace");