Show CPU and memory usage in interactive mode (#63)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

cli.js

@@ -21,7 +21,9 @@ const cli = meow(`
 
 	To kill a port, prefix it with a colon. For example: :8080.
 
-	Run without arguments to use the interactive interface.
+	Run without arguments to use the interactive mode.
+	In interactive mode, 🚦A.B% indicates high CPU usage, 🐏C.D% indicates high memory usage.
+
 	The process name is case insensitive.
 `, {
 	inferType: true,

interactive.js

@@ -20,29 +20,69 @@ const nameFilter = (input, proc) => {
 	return proc.name.toLowerCase().includes(input.toLowerCase());
 };
 
+const preferNotMatching = matches => (a, b) => {
+	const aMatches = matches(a);
+	return matches(b) === aMatches ? 0 : (aMatches ? 1 : -1);
+};
+
+const deprioritizedProcesses = new Set(['iTerm', 'iTerm2', 'fkill']);
+const isDeprioritizedProcess = proc => deprioritizedProcesses.has(proc.name);
+const preferNotDeprioritized = preferNotMatching(isDeprioritizedProcess);
+const preferHighPerformanceImpact = (a, b) => numSort.desc(a.cpu + a.memory, b.cpu + b.memory);
+const preferLowAlphanumericNames = (a, b) => a.name.localeCompare(b.name);
+
+const preferHeurisicallyInterestingProcesses = (a, b) => {
+	let result;
+
+	result = preferNotDeprioritized(a, b);
+	if (result !== 0) {
+		return result;
+	}
+
+	result = preferHighPerformanceImpact(a, b);
+	if (result !== 0) {
+		return result;
+	}
+
+	return preferLowAlphanumericNames(a, b);
+};
+
 const filterProcesses = (input, processes, flags) => {
 	const filters = {
 		name: proc => input ? nameFilter(input, proc) : true,
 		verbose: proc => input ? (process.platform === 'win32' ? proc.name : proc.cmd).toLowerCase().includes(input.toLowerCase()) : true
 	};
 
+	const memoryThreshold = flags.verbose ? 0.0 : 1.0;
+	const cpuThreshold = flags.verbose ? 0.0 : 3.0;
+
 	return processes
 		.filter(proc => !(
 			proc.name.endsWith('-helper') ||
 			proc.name.endsWith('Helper') ||
 			proc.name.endsWith('HelperApp')
 		))
 		.filter(flags.verbose ? filters.verbose : filters.name)
-		.sort((a, b) => numSort.asc(a.pid, b.pid))
+		.sort(preferHeurisicallyInterestingProcesses)
 		.map(proc => {
+			const renderPercentage = percents => {
+				const digits = Math.floor(percents * 10).toString().padStart(2, '0');
+				const whole = digits.substr(0, digits.length - 1);
+				const fraction = digits.substr(digits.length - 1);
+				return fraction === '0' ? `${whole}%` : `${whole}.${fraction}%`;
+			};
+
 			const lineLength = process.stdout.columns || 80;
-			const ports = proc.ports.slice(0, 4).map(x => `:${x}`).join(' ').trim();
-			const margins = commandLineMargins + proc.pid.toString().length + ports.length;
+			const ports = proc.ports.length === 0 ? '' : (' ' + proc.ports.slice(0, 4).map(x => `:${x}`).join(' '));
+			const memory = (proc.memory !== undefined && (proc.memory > memoryThreshold)) ? ` 🐏${renderPercentage(proc.memory)}` : '';
+			const cpu = (proc.cpu !== undefined && (proc.cpu > cpuThreshold)) ? `🚦${renderPercentage(proc.cpu)}` : '';
+			const margins = commandLineMargins + proc.pid.toString().length + ports.length + memory.length + cpu.length;
 			const length = lineLength - margins;
 			const name = cliTruncate(flags.verbose && process.platform !== 'win32' ? proc.cmd : proc.name, length, {position: 'middle'});
+			const spacer = lineLength === process.stdout.columns ? ''.padEnd(length - name.length) : '';
 
 			return {
-				name: `${name} ${chalk.dim(proc.pid)} ${chalk.dim.magenta(ports)}`,
+				name: `${name} ${chalk.dim(proc.pid)}${spacer}${chalk.dim(ports)}${cpu}${memory}`,
 				value: proc.pid
 			};
 		});
@@ -107,6 +147,7 @@ const init = async flags => {
 		pidFromPort.list(),
 		psList({all: false})
 	]);
+
 	const procs = processes.map(proc => ({...proc, ports: getPortsFromPid(proc.pid, pids)}));
 	listProcesses(procs, flags);
 };