Improve feedback display when tracing events

lib/index.js

@@ -5,6 +5,7 @@ require("./utils/other.js");
 require("./utils/global.js");
 require("./utils/buffer.js");
 require("./utils/cursor.js");
+require("./utils/diagnostics.js");
 
 // Custom commands
 require("./commands/display.js");

lib/utils/diagnostics.js

@@ -0,0 +1,56 @@
+"use strict";
+
+const prot = atom.emitter.constructor.prototype;
+const emit = prot.emit;
+
+module.exports = {
+	countdown,
+	traceEmissions,
+};
+
+
+/**
+ * Return a {@link Promise} that resolves after a delay,
+ * counting each second that passes.
+ *
+ * @example countdown(10).then(() => console.log("Happy new year!"));
+ * @param {Number} [ticks=5] - Countdown duration in seconds
+ * @return {Promise<void>}
+ */
+async function countdown(ticks = 5){
+	return new Promise((resolve, reject) => {
+		console.log(ticks--);
+		const timer = setInterval(() => ticks <= 0
+			? resolve(clearInterval(timer))
+			: console.log(ticks--), 1000);
+	});
+}
+
+
+/**
+ * Toggle logging of event emissions in the dev-console.
+ *
+ * @param {Boolean} active - Whether to trace emissions or not
+ * @param {Number} [duration=5] - Stop tracing after 𝑁 seconds
+ * @param {Number} [delay=5] - Wait 𝑁 seconds before tracing
+ * @return {Promise<void>}
+ */
+async function traceEmissions(active = emit === prot.emit, duration = 0, delay = 0){
+	if(duration > 0) setTimeout(() => traceEmissions(false), duration);
+	if(delay    > 0) await countdown(delay);
+	if(active){
+		console.groupCollapsed("Traced emissions");
+		prot.emit = function(name, ...args){
+			if("did-update-state" !== name){
+				const trace = {context: this, arguments};
+				Error.captureStackTrace(trace);
+				console.dir({context: this, arguments, trace, [Symbol.toStringTag]: name});
+			}
+			emit.apply(this, arguments);
+		};
+	}
+	else{
+		console.groupEnd();
+		prot.emit = emit;
+	}
+}

lib/utils/global.js

@@ -72,29 +72,7 @@ Object.assign(global, {
 	util:     require("util"),
 	zlib:     require("zlib"),
 
-	traceEmissions: (function(){
-		const prot = atom.emitter.constructor.prototype;
-		const emit = prot.emit;
-		return function(active){
-			if(undefined === active)
-				active = emit === prot.emit;
-			prot.emit = !active ? emit : function(name, ...args){
-				if("did-update-state" !== name){
-					const trace = {};
-					Error.captureStackTrace(trace);
-					trace.context = this;
-					setTimeout(() => {
-						Object.defineProperty(args, "trace", {
-							enumerable: false,
-							value: trace,
-						});
-					}, 10);
-					console.log(name, args);
-				}
-				emit.apply(this, arguments);
-			};
-		};
-	}()),
+	...require("./diagnostics.js"),
 
 	bin(value, a){
 		value = value.toString(2).split("");