From e784b0ef8099d714852c172d73d3e29184ad6e76 Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Wed, 12 Dec 2018 02:29:39 +0100
Subject: [PATCH 1/8] start implementing output formatting
 https://github.com/visionmedia/debug/issues/582

---
 src/common.js |   6 +++
 src/node.js   | 107 ++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 100 insertions(+), 13 deletions(-)

diff --git a/src/common.js b/src/common.js
index 0b6d0b64..b39fc261 100644
--- a/src/common.js
+++ b/src/common.js
@@ -36,6 +36,11 @@ function setup(env) {
 	*/
 	createDebug.formatters = {};
 
+	/**
+	* Map of formatting handling functions, for output formatting.
+	*/
+	createDebug.outputFormatters = {};
+
 	/**
 	* Selects a color for a debug namespace
 	* @param {String} namespace The namespace string for the for the debug instance to be colored
@@ -117,6 +122,7 @@ function setup(env) {
 		debug.namespace = namespace;
 		debug.enabled = createDebug.enabled(namespace);
 		debug.useColors = createDebug.useColors();
+		debug.format = createDebug.getFormat() || '%{H:M-Z} %n %m %+';
 		debug.color = selectColor(namespace);
 		debug.destroy = destroy;
 		debug.extend = extend;
diff --git a/src/node.js b/src/node.js
index 5e1f1541..70d53333 100644
--- a/src/node.js
+++ b/src/node.js
@@ -15,6 +15,7 @@ exports.formatArgs = formatArgs;
 exports.save = save;
 exports.load = load;
 exports.useColors = useColors;
+exports.getFormat = getFormat;
 
 /**
  * Colors.
@@ -137,7 +138,10 @@ exports.inspectOpts = Object.keys(process.env).filter(key => {
 	} else if (val === 'null') {
 		val = null;
 	} else {
-		val = Number(val);
+		let asNumber = Number(val);
+		if (!isNaN(asNumber)) {
+			val = asNumber;
+		}
 	}
 
 	obj[prop] = val;
@@ -154,6 +158,14 @@ function useColors() {
 		tty.isatty(process.stderr.fd);
 }
 
+/**
+ * Returns DEBUG_FORMAT if specified, or false otherwise
+ */
+
+function getFormat() {
+	return 'format' in exports.inspectOpts && exports.inspectOpts.format;
+}
+
 /**
  * Adds ANSI color escape codes if enabled.
  *
@@ -161,18 +173,35 @@ function useColors() {
  */
 
 function formatArgs(args) {
-	const {namespace: name, useColors} = this;
-
-	if (useColors) {
-		const c = this.color;
-		const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
-		const prefix = `  ${colorCode};1m${name} \u001B[0m`;
-
-		args[0] = prefix + args[0].split('\n').join('\n' + prefix);
-		args.push(colorCode + 'm+' + module.exports.humanize(this.diff) + '\u001B[0m');
-	} else {
-		args[0] = getDate() + name + ' ' + args[0];
-	}
+	var formatted = this.format;
+
+	// Apply any `outputFormatters` transformations
+	formatted = formatted.replace(/%(J?[a-zA-Z+]|J?\{.+\})/g, (match, format) => {
+		//%J* are passed to JSON.stringify
+		let stringify = false;
+		if (format.startsWith('J')) {
+			format = format.replace(/^J/, '');
+			stringify = true;
+		}
+
+		let formatter;
+		//not really sure how to handle time at this point
+		if (format.startsWith('{')) {
+			formatter = outputFormatters._time;
+		} else {
+			 formatter = outputFormatters[format];
+		}
+		if (typeof formatter === 'function') {
+			match = formatter.call(this, format, args);
+			if (stringify) {
+				match = JSON.stringify(match)
+			}
+		}
+
+		return match;
+	});
+
+	args[0] = formatted;
 }
 
 function getDate() {
@@ -255,3 +284,55 @@ formatters.O = function (v) {
 	this.inspectOpts.colors = this.useColors;
 	return util.inspect(v, this.inspectOpts);
 };
+
+const { outputFormatters } = module.exports;
+
+/**
+ * Map %m to outputting message
+ */
+
+outputFormatters.m = function(format, args) {
+	return args;
+}
+
+/**
+ * Map %m to outputting diff
+ */
+
+outputFormatters['+'] = function(format, args) {
+	const diff = 'm+' + module.exports.humanize(this.diff);
+
+	if (this.useColors) {
+		const c = this.color;
+		const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
+
+		return colorCode + diff + '\u001B[0m';
+	} else {
+		return diff;
+	}
+}
+
+/**
+ * Map %n to outputting namespace prefix
+ */
+
+outputFormatters.n = function(format, args) {
+	if (this.useColors) {
+		const c = this.color;
+		const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
+
+		return `  ${colorCode};1m${this.name} \u001B[0m`;;
+	} else {
+		return this.name;
+	}
+}
+
+
+/**
+ * Map %_time to handling time...?
+ */
+
+outputFormatters._time = function(format, args) {
+	return getDate();
+}
+

From a612347ad2ff04bbd491dc7c17b5bd3fcb6f7e09 Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Wed, 12 Dec 2018 23:28:58 +0100
Subject: [PATCH 2/8] move formatting mostly into common.js

---
 src/common.js | 90 ++++++++++++++++++++++++++++++++++++++++++++---
 src/node.js   | 97 ++++-----------------------------------------------
 2 files changed, 93 insertions(+), 94 deletions(-)

diff --git a/src/common.js b/src/common.js
index b39fc261..c57f5378 100644
--- a/src/common.js
+++ b/src/common.js
@@ -38,9 +38,53 @@ function setup(env) {
 
 	/**
 	* Map of formatting handling functions, for output formatting.
+	* m and _time are special hardcoded keys.
 	*/
 	createDebug.outputFormatters = {};
 
+	/**
+	 * Map %m to outputting diff
+	 */
+
+	createDebug.outputFormatters.m = function(format, args) {
+		return args;
+	}
+
+	/**
+	 * Map %+ to outputting diff
+	 */
+
+	createDebug.outputFormatters['+'] = function(format, args) {
+		const diff = '+' + createDebug.humanize(this.diff);
+		if (this.useColors) {
+			return this.applyColor(diff);
+		} else {
+			return diff;
+		}
+	}
+
+	/**
+	 * Map %n to outputting namespace prefix
+	 */
+
+	createDebug.outputFormatters.n = function(format, args) {
+		if (this.useColors) {
+			return this.applyColor(this.name, true);
+		} else {
+			return this.name;
+		}
+	}
+
+	/**
+	 * Map %_time to handling time...?
+	 */
+
+	createDebug.outputFormatters._time = function(format, args) {
+		//doesn't respect `exports.inspectOpts.hideDate`
+		//browser doesn't have date
+		return new Date().toISOString();
+	}
+
 	/**
 	* Selects a color for a debug namespace
 	* @param {String} namespace The namespace string for the for the debug instance to be colored
@@ -112,18 +156,56 @@ function setup(env) {
 				return match;
 			});
 
-			// Apply env-specific formatting (colors, etc.)
-			createDebug.formatArgs.call(self, args);
+			// Apply relevant `outputFormatters` to `format`
+			let reg = /%(J?[a-zA-Z+]|J?\{.+\})/, formattedArgs = [], res;
+			let outputFormat = self.format; //make a copy of the format
+			while (res = outputFormat.match(reg)) {
+				let [matched, formatToken] = res, stringify = false, formatter, formatted;
+				//split out the part before the matched format token
+				let split = outputFormat.slice(0, res.index);
+				outputFormat = outputFormat.slice(res.index + matched.length);
+
+				//and add it to the arguments
+				if (split.length > 0) {
+					formattedArgs.push(split);
+				}
+
+				//%J* are passed to JSON.stringify
+				if (formatToken.startsWith('J')) {
+					formatToken = formatToken.replace(/^J/, '');
+					stringify = true;
+				}
+
+				//not really sure how to handle time at this point
+				if (formatToken.startsWith('{')) {
+					formatter = createDebug.outputFormatters._time;
+				} else {
+					formatter = createDebug.outputFormatters[formatToken];
+				}
+				if (typeof formatter === 'function') {
+					formatted = formatter.call(self, formatToken, args);
+					if (stringify) {
+						formatted = JSON.stringify(formatted)
+					}
+
+					if (Array.isArray(formatted)) { //intended to concatenate %m's args in the middle of the format
+						formattedArgs = formattedArgs.concat(formatted);
+					} else {
+						formattedArgs.push(formatted);
+					}
+				}
+			}
 
 			const logFn = self.log || createDebug.log;
-			logFn.apply(self, args);
+			logFn.apply(self, formattedArgs);
 		}
 
 		debug.namespace = namespace;
 		debug.enabled = createDebug.enabled(namespace);
 		debug.useColors = createDebug.useColors();
-		debug.format = createDebug.getFormat() || '%{H:M-Z} %n %m %+';
+		debug.format = createDebug.getFormat() || '%{H:M-Z}%n%m%+'; //'  %n%m%+'
 		debug.color = selectColor(namespace);
+		debug.applyColor = createDebug.applyColor.bind(debug);
 		debug.destroy = destroy;
 		debug.extend = extend;
 		// Debug.formatArgs = formatArgs;
diff --git a/src/node.js b/src/node.js
index 70d53333..5c23486b 100644
--- a/src/node.js
+++ b/src/node.js
@@ -11,7 +11,7 @@ const util = require('util');
 
 exports.init = init;
 exports.log = log;
-exports.formatArgs = formatArgs;
+exports.applyColor = applyColor;
 exports.save = save;
 exports.load = load;
 exports.useColors = useColors;
@@ -172,43 +172,12 @@ function getFormat() {
  * @api public
  */
 
-function formatArgs(args) {
-	var formatted = this.format;
+function applyColor(str, bold = false) {
+	//I think doing this each time is a waste, colorCode could be stored in some variable?
+	const c = this.color;
+	const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
 
-	// Apply any `outputFormatters` transformations
-	formatted = formatted.replace(/%(J?[a-zA-Z+]|J?\{.+\})/g, (match, format) => {
-		//%J* are passed to JSON.stringify
-		let stringify = false;
-		if (format.startsWith('J')) {
-			format = format.replace(/^J/, '');
-			stringify = true;
-		}
-
-		let formatter;
-		//not really sure how to handle time at this point
-		if (format.startsWith('{')) {
-			formatter = outputFormatters._time;
-		} else {
-			 formatter = outputFormatters[format];
-		}
-		if (typeof formatter === 'function') {
-			match = formatter.call(this, format, args);
-			if (stringify) {
-				match = JSON.stringify(match)
-			}
-		}
-
-		return match;
-	});
-
-	args[0] = formatted;
-}
-
-function getDate() {
-	if (exports.inspectOpts.hideDate) {
-		return '';
-	}
-	return new Date().toISOString() + ' ';
+	return colorCode + (bold ? ';1' : '') + 'm' + str + '\u001B[0m';
 }
 
 /**
@@ -283,56 +252,4 @@ formatters.o = function (v) {
 formatters.O = function (v) {
 	this.inspectOpts.colors = this.useColors;
 	return util.inspect(v, this.inspectOpts);
-};
-
-const { outputFormatters } = module.exports;
-
-/**
- * Map %m to outputting message
- */
-
-outputFormatters.m = function(format, args) {
-	return args;
-}
-
-/**
- * Map %m to outputting diff
- */
-
-outputFormatters['+'] = function(format, args) {
-	const diff = 'm+' + module.exports.humanize(this.diff);
-
-	if (this.useColors) {
-		const c = this.color;
-		const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
-
-		return colorCode + diff + '\u001B[0m';
-	} else {
-		return diff;
-	}
-}
-
-/**
- * Map %n to outputting namespace prefix
- */
-
-outputFormatters.n = function(format, args) {
-	if (this.useColors) {
-		const c = this.color;
-		const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
-
-		return `  ${colorCode};1m${this.name} \u001B[0m`;;
-	} else {
-		return this.name;
-	}
-}
-
-
-/**
- * Map %_time to handling time...?
- */
-
-outputFormatters._time = function(format, args) {
-	return getDate();
-}
-
+};
\ No newline at end of file

From 2b51112dc318dff3d27c625f413472863171354c Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Fri, 14 Dec 2018 00:10:46 +0100
Subject: [PATCH 3/8] fix %n to correctly show namespace

---
 src/common.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/common.js b/src/common.js
index c57f5378..8b4ae9f9 100644
--- a/src/common.js
+++ b/src/common.js
@@ -69,9 +69,9 @@ function setup(env) {
 
 	createDebug.outputFormatters.n = function(format, args) {
 		if (this.useColors) {
-			return this.applyColor(this.name, true);
+			return this.applyColor(this.namespace, true);
 		} else {
-			return this.name;
+			return this.namespace;
 		}
 	}
 

From 73ad1ed963758d9b73799589935cb76a709f2c2c Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Fri, 14 Dec 2018 00:18:46 +0100
Subject: [PATCH 4/8] properly match current version's formatting

---
 src/node.js | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/node.js b/src/node.js
index 5c23486b..3a877ffd 100644
--- a/src/node.js
+++ b/src/node.js
@@ -159,11 +159,26 @@ function useColors() {
 }
 
 /**
- * Returns DEBUG_FORMAT if specified, or false otherwise
+ * If DEBUG_FORMAT if specified, returns it.
+ * Otherwise, returns a format matching previous version's based on DEBUG_COLORS and DEBUG_HIDE_DATE
  */
 
 function getFormat() {
-	return 'format' in exports.inspectOpts && exports.inspectOpts.format;
+	const useColors = 'colors' in exports.inspectOpts ?
+		Boolean(exports.inspectOpts.colors) :
+		tty.isatty(process.stderr.fd);
+
+	if ('format' in exports.inspectOpts) {
+		return exports.inspectOpts.format;
+	} else {
+		if (useColors) {
+			return ' %n%m%+'; //'  %n %m %+'
+		} else if (exports.inspectOpts.hideDate) {
+			return '%n%m'; //'%n %m'
+		} else {
+			return '%{%FT%T.%LZ%M-Z}%n%m'; //'%{%FT%T.%LZ%M-Z} %n %m'
+		}
+	}
 }
 
 /**

From 1e18a8e9c11ccf716c24f3be8ac3070f7498091e Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Fri, 14 Dec 2018 14:24:39 +0100
Subject: [PATCH 5/8] move args handling to outputFormatters.m()

---
 src/common.js | 59 ++++++++++++++++++++++++++++-----------------------
 1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/src/common.js b/src/common.js
index 8b4ae9f9..973ac4eb 100644
--- a/src/common.js
+++ b/src/common.js
@@ -47,6 +47,38 @@ function setup(env) {
 	 */
 
 	createDebug.outputFormatters.m = function(format, args) {
+		args[0] = createDebug.coerce(args[0]);
+
+		if (typeof args[0] !== 'string') {
+			// Anything else let's inspect with %O
+			/**
+			 * Note: This only inspects the first argument,
+			 * so if debug({foo: "bar"}, {foo: "bar"}) is passed
+			 * only the first object will be colored by node's formatters.O
+			 */
+			args.unshift('%O');
+		}
+
+		// Apply any `formatters` transformations
+		let index = 0;
+		args[0] = args[0].replace(/%([a-zA-Z%])/g, (match, format) => {
+			// If we encounter an escaped % then don't increase the array index
+			if (match === '%%') {
+				return match;
+			}
+			index++;
+			const formatter = createDebug.formatters[format];
+			if (typeof formatter === 'function') {
+				const val = args[index];
+				match = formatter.call(this, val);
+
+				// Now we need to remove `args[index]` since it's inlined in the `format`
+				args.splice(index, 1);
+				index--;
+			}
+			return match;
+		});
+
 		return args;
 	}
 
@@ -129,33 +161,6 @@ function setup(env) {
 			self.curr = curr;
 			prevTime = curr;
 
-			args[0] = createDebug.coerce(args[0]);
-
-			if (typeof args[0] !== 'string') {
-				// Anything else let's inspect with %O
-				args.unshift('%O');
-			}
-
-			// Apply any `formatters` transformations
-			let index = 0;
-			args[0] = args[0].replace(/%([a-zA-Z%])/g, (match, format) => {
-				// If we encounter an escaped % then don't increase the array index
-				if (match === '%%') {
-					return match;
-				}
-				index++;
-				const formatter = createDebug.formatters[format];
-				if (typeof formatter === 'function') {
-					const val = args[index];
-					match = formatter.call(self, val);
-
-					// Now we need to remove `args[index]` since it's inlined in the `format`
-					args.splice(index, 1);
-					index--;
-				}
-				return match;
-			});
-
 			// Apply relevant `outputFormatters` to `format`
 			let reg = /%(J?[a-zA-Z+]|J?\{.+\})/, formattedArgs = [], res;
 			let outputFormat = self.format; //make a copy of the format

From 5313c69f83bfc9e8607aa9adf5a52249369eccd0 Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Fri, 14 Dec 2018 15:13:21 +0100
Subject: [PATCH 6/8] implement metaformatters (color, JSON.stringify)

---
 src/common.js | 76 +++++++++++++++++++++++++++++++++++++--------------
 src/node.js   |  2 +-
 2 files changed, 56 insertions(+), 22 deletions(-)

diff --git a/src/common.js b/src/common.js
index 973ac4eb..ba08e79e 100644
--- a/src/common.js
+++ b/src/common.js
@@ -87,12 +87,7 @@ function setup(env) {
 	 */
 
 	createDebug.outputFormatters['+'] = function(format, args) {
-		const diff = '+' + createDebug.humanize(this.diff);
-		if (this.useColors) {
-			return this.applyColor(diff);
-		} else {
-			return diff;
-		}
+		return '+' + createDebug.humanize(this.diff);
 	}
 
 	/**
@@ -100,11 +95,7 @@ function setup(env) {
 	 */
 
 	createDebug.outputFormatters.n = function(format, args) {
-		if (this.useColors) {
-			return this.applyColor(this.namespace, true);
-		} else {
-			return this.namespace;
-		}
+		return this.namespace;
 	}
 
 	/**
@@ -112,11 +103,48 @@ function setup(env) {
 	 */
 
 	createDebug.outputFormatters._time = function(format, args) {
-		//doesn't respect `exports.inspectOpts.hideDate`
 		//browser doesn't have date
 		return new Date().toISOString();
 	}
 
+
+	/**
+	* Map of meta-formatters which are applied to outputFormatters
+	*/
+	createDebug.metaFormatters = {};
+
+	/**
+	 * Map %J* to `JSON.stringify()`
+	 */
+
+	createDebug.outputFormatters.J = function(v) {
+		return JSON.stringify(v);
+	}
+
+	/**
+	 * Map %c* to to `applyColor()`
+	 */
+
+	createDebug.outputFormatters.c = function(v) {
+		if (this.useColors) {
+			return this.applyColor(v);
+		} else {
+			return v;
+		}
+	}
+
+	/**
+	 * Map %C* to to `applyColor(arg, bold = true)` (node)
+	 */
+
+	createDebug.outputFormatters.C = function(v) {
+		if (this.useColors) {
+			return this.applyColor(v, true);
+		} else {
+			return v;
+		}
+	}
+
 	/**
 	* Selects a color for a debug namespace
 	* @param {String} namespace The namespace string for the for the debug instance to be colored
@@ -162,10 +190,10 @@ function setup(env) {
 			prevTime = curr;
 
 			// Apply relevant `outputFormatters` to `format`
-			let reg = /%(J?[a-zA-Z+]|J?\{.+\})/, formattedArgs = [], res;
+			let reg = /%([a-zA-Z+]+|[a-zA-Z]*?\{.+\})/, formattedArgs = [], res;
 			let outputFormat = self.format; //make a copy of the format
 			while (res = outputFormat.match(reg)) {
-				let [matched, formatToken] = res, stringify = false, formatter, formatted;
+				let [matched, formatToken] = res, formatter, formatted;
 				//split out the part before the matched format token
 				let split = outputFormat.slice(0, res.index);
 				outputFormat = outputFormat.slice(res.index + matched.length);
@@ -175,10 +203,12 @@ function setup(env) {
 					formattedArgs.push(split);
 				}
 
-				//%J* are passed to JSON.stringify
-				if (formatToken.startsWith('J')) {
-					formatToken = formatToken.replace(/^J/, '');
-					stringify = true;
+				let metaFormatters = [];
+				// Extract metaformatters
+				while (formatToken.length > 1 && !formatToken.startsWith('{')) {
+					const metaFormatterToken = formatToken.slice(0, 1);
+					formatToken = formatToken.slice(1);
+					metaFormatters.push(createDebug.outputFormatters[metaFormatterToken]);
 				}
 
 				//not really sure how to handle time at this point
@@ -189,9 +219,13 @@ function setup(env) {
 				}
 				if (typeof formatter === 'function') {
 					formatted = formatter.call(self, formatToken, args);
-					if (stringify) {
-						formatted = JSON.stringify(formatted)
-					}
+
+					// Apply metaFormatters
+					metaFormatters.forEach(metaFormatter => {
+						if (typeof metaFormatter === "function") {
+							formatted = metaFormatter.call(self, formatted);
+						}
+					});
 
 					if (Array.isArray(formatted)) { //intended to concatenate %m's args in the middle of the format
 						formattedArgs = formattedArgs.concat(formatted);
diff --git a/src/node.js b/src/node.js
index 3a877ffd..51cbf75e 100644
--- a/src/node.js
+++ b/src/node.js
@@ -172,7 +172,7 @@ function getFormat() {
 		return exports.inspectOpts.format;
 	} else {
 		if (useColors) {
-			return ' %n%m%+'; //'  %n %m %+'
+			return ' %Cn%m%c+'; //'  %n %m %+'
 		} else if (exports.inspectOpts.hideDate) {
 			return '%n%m'; //'%n %m'
 		} else {

From 69b5a48ce4fcbaab2fa400e122785c86017ac29e Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Fri, 14 Dec 2018 16:07:07 +0100
Subject: [PATCH 7/8] add `%d` `outputFormatter` to show exact ms diff
 https://github.com/visionmedia/debug/issues/626

---
 src/common.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/common.js b/src/common.js
index ba08e79e..7038fa78 100644
--- a/src/common.js
+++ b/src/common.js
@@ -83,13 +83,21 @@ function setup(env) {
 	}
 
 	/**
-	 * Map %+ to outputting diff
+	 * Map %+ to humanize()'s defaults (1000ms diff => "1s")
 	 */
 
 	createDebug.outputFormatters['+'] = function(format, args) {
 		return '+' + createDebug.humanize(this.diff);
 	}
 
+	/**
+	 * Map %d to returning milliseconds
+	 */
+
+	createDebug.outputFormatters.d = function(format, args) {
+		return '+' + this.diff + "ms";
+	}
+
 	/**
 	 * Map %n to outputting namespace prefix
 	 */

From 8fa6444b043089a08080197f272013bcdd2ad508 Mon Sep 17 00:00:00 2001
From: chagris <>
Date: Fri, 14 Dec 2018 16:25:35 +0100
Subject: [PATCH 8/8] fix most issues from the linter

---
 src/common.js | 66 +++++++++++++++++++++++++++------------------------
 src/node.js   | 12 +++++-----
 2 files changed, 41 insertions(+), 37 deletions(-)

diff --git a/src/common.js b/src/common.js
index 7038fa78..2c66873a 100644
--- a/src/common.js
+++ b/src/common.js
@@ -43,10 +43,10 @@ function setup(env) {
 	createDebug.outputFormatters = {};
 
 	/**
-	 * Map %m to outputting diff
+	 * Map %m to applying formatters to arguments
 	 */
 
-	createDebug.outputFormatters.m = function(format, args) {
+	createDebug.outputFormatters.m = function (_, args) {
 		args[0] = createDebug.coerce(args[0]);
 
 		if (typeof args[0] !== 'string') {
@@ -80,41 +80,40 @@ function setup(env) {
 		});
 
 		return args;
-	}
+	};
 
 	/**
 	 * Map %+ to humanize()'s defaults (1000ms diff => "1s")
 	 */
 
-	createDebug.outputFormatters['+'] = function(format, args) {
+	createDebug.outputFormatters['+'] = function () {
 		return '+' + createDebug.humanize(this.diff);
-	}
+	};
 
 	/**
 	 * Map %d to returning milliseconds
 	 */
 
-	createDebug.outputFormatters.d = function(format, args) {
-		return '+' + this.diff + "ms";
-	}
+	createDebug.outputFormatters.d = function () {
+		return '+' + this.diff + 'ms';
+	};
 
 	/**
 	 * Map %n to outputting namespace prefix
 	 */
 
-	createDebug.outputFormatters.n = function(format, args) {
+	createDebug.outputFormatters.n = function () {
 		return this.namespace;
-	}
+	};
 
 	/**
 	 * Map %_time to handling time...?
 	 */
 
-	createDebug.outputFormatters._time = function(format, args) {
-		//browser doesn't have date
+	createDebug.outputFormatters._time = function (format) {
+		// Browser doesn't have date
 		return new Date().toISOString();
-	}
-
+	};
 
 	/**
 	* Map of meta-formatters which are applied to outputFormatters
@@ -125,33 +124,33 @@ function setup(env) {
 	 * Map %J* to `JSON.stringify()`
 	 */
 
-	createDebug.outputFormatters.J = function(v) {
+	createDebug.outputFormatters.J = function (v) {
 		return JSON.stringify(v);
-	}
+	};
 
 	/**
 	 * Map %c* to to `applyColor()`
 	 */
 
-	createDebug.outputFormatters.c = function(v) {
+	createDebug.outputFormatters.c = function (v) {
 		if (this.useColors) {
 			return this.applyColor(v);
 		} else {
 			return v;
 		}
-	}
+	};
 
 	/**
 	 * Map %C* to to `applyColor(arg, bold = true)` (node)
 	 */
 
-	createDebug.outputFormatters.C = function(v) {
+	createDebug.outputFormatters.C = function (v) {
 		if (this.useColors) {
 			return this.applyColor(v, true);
 		} else {
 			return v;
 		}
-	}
+	};
 
 	/**
 	* Selects a color for a debug namespace
@@ -198,20 +197,25 @@ function setup(env) {
 			prevTime = curr;
 
 			// Apply relevant `outputFormatters` to `format`
-			let reg = /%([a-zA-Z+]+|[a-zA-Z]*?\{.+\})/, formattedArgs = [], res;
-			let outputFormat = self.format; //make a copy of the format
+			const reg = /%([a-zA-Z+]+|[a-zA-Z]*?\{.+\})/;
+			let formattedArgs = [];
+			let res;
+			let outputFormat = self.format; // Make a copy of the format
 			while (res = outputFormat.match(reg)) {
-				let [matched, formatToken] = res, formatter, formatted;
-				//split out the part before the matched format token
-				let split = outputFormat.slice(0, res.index);
+				let [matched, formatToken] = res;
+				let formatter;
+				let formatted;
+
+				// Split out the part before the matched format token
+				const split = outputFormat.slice(0, res.index);
 				outputFormat = outputFormat.slice(res.index + matched.length);
 
-				//and add it to the arguments
+				// And add it to the arguments
 				if (split.length > 0) {
 					formattedArgs.push(split);
 				}
 
-				let metaFormatters = [];
+				const metaFormatters = [];
 				// Extract metaformatters
 				while (formatToken.length > 1 && !formatToken.startsWith('{')) {
 					const metaFormatterToken = formatToken.slice(0, 1);
@@ -219,7 +223,7 @@ function setup(env) {
 					metaFormatters.push(createDebug.outputFormatters[metaFormatterToken]);
 				}
 
-				//not really sure how to handle time at this point
+				// Not really sure how to handle time at this point
 				if (formatToken.startsWith('{')) {
 					formatter = createDebug.outputFormatters._time;
 				} else {
@@ -230,12 +234,12 @@ function setup(env) {
 
 					// Apply metaFormatters
 					metaFormatters.forEach(metaFormatter => {
-						if (typeof metaFormatter === "function") {
+						if (typeof metaFormatter === 'function') {
 							formatted = metaFormatter.call(self, formatted);
 						}
 					});
 
-					if (Array.isArray(formatted)) { //intended to concatenate %m's args in the middle of the format
+					if (Array.isArray(formatted)) { // Intended to concatenate %m's args in the middle of the format
 						formattedArgs = formattedArgs.concat(formatted);
 					} else {
 						formattedArgs.push(formatted);
@@ -250,7 +254,7 @@ function setup(env) {
 		debug.namespace = namespace;
 		debug.enabled = createDebug.enabled(namespace);
 		debug.useColors = createDebug.useColors();
-		debug.format = createDebug.getFormat() || '%{H:M-Z}%n%m%+'; //'  %n%m%+'
+		debug.format = createDebug.getFormat() || '%{H:M-Z}%n%m%+'; // '  %n%m%+'
 		debug.color = selectColor(namespace);
 		debug.applyColor = createDebug.applyColor.bind(debug);
 		debug.destroy = destroy;
diff --git a/src/node.js b/src/node.js
index 51cbf75e..9075c07c 100644
--- a/src/node.js
+++ b/src/node.js
@@ -138,7 +138,7 @@ exports.inspectOpts = Object.keys(process.env).filter(key => {
 	} else if (val === 'null') {
 		val = null;
 	} else {
-		let asNumber = Number(val);
+		const asNumber = Number(val);
 		if (!isNaN(asNumber)) {
 			val = asNumber;
 		}
@@ -172,11 +172,11 @@ function getFormat() {
 		return exports.inspectOpts.format;
 	} else {
 		if (useColors) {
-			return ' %Cn%m%c+'; //'  %n %m %+'
+			return ' %Cn%m%c+'; // '  %n %m %+'
 		} else if (exports.inspectOpts.hideDate) {
-			return '%n%m'; //'%n %m'
+			return '%n%m'; // '%n %m'
 		} else {
-			return '%{%FT%T.%LZ%M-Z}%n%m'; //'%{%FT%T.%LZ%M-Z} %n %m'
+			return '%{%FT%T.%LZ%M-Z}%n%m'; // '%{%FT%T.%LZ%M-Z} %n %m'
 		}
 	}
 }
@@ -188,7 +188,7 @@ function getFormat() {
  */
 
 function applyColor(str, bold = false) {
-	//I think doing this each time is a waste, colorCode could be stored in some variable?
+	// I think doing this each time is a waste, colorCode could be stored in some variable?
 	const c = this.color;
 	const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
 
@@ -267,4 +267,4 @@ formatters.o = function (v) {
 formatters.O = function (v) {
 	this.inspectOpts.colors = this.useColors;
 	return util.inspect(v, this.inspectOpts);
-};
\ No newline at end of file
+};