chore: using cron-parser package parsing job schedules

package.json

@@ -46,6 +46,7 @@
     "@types/shelljs": "^0.8.5",
     "@types/table": "^4.0.7",
     "chalk": "^2.4.2",
+    "cron-parser": "^2.13.0",
     "flexi-path": "^0.1.2-beta.16",
     "nordvpn-server-lister": "https://github.com/jaspenlind/nordvpn-server-lister/releases/download/v0.0.1-alpha.3/nordvpn-server-lister-0.0.1-alpha.3.tgz",
     "option-parser": "https://github.com/jaspenlind/option-parser/releases/download/v0.0.1-alpha.6/option-parser-0.0.1-alpha.6.tgz",

src/lib/arrayHelper.ts

@@ -1,8 +1,67 @@
-export const any = <T>(array: ArrayLike<T>) => array.length > 0;
+type NullableArray<T> = ArrayLike<T> | null;
 
-export const isEmpty = <T>(array: ArrayLike<T>) => !any(array);
+export const indeces = {
+  empty: 0,
+  first: 0,
+  lastIndexSubtrahend: 1
+};
 
-export const last = <T>(array: ArrayLike<T>): T => array[array.length - 1];
+export const any = <T>(array: NullableArray<T>) =>
+  (array && array.length > indeces.empty) || false;
+
+export const isEmpty = <T>(array: NullableArray<T>) => !any(array);
+
+export const firstOrDefault = <T>(
+  array: NullableArray<T>,
+  defaultValue: T | null = null
+): T | null => (array && array[indeces.first]) || defaultValue;
+
+export const first = <T>(array: NullableArray<T>) =>
+  firstOrDefault(array) || undefined;
+
+export const lastOrDefault = <T>(
+  array: NullableArray<T>,
+  defaultValue: T | null = null
+): T | null =>
+  (array && array[array.length - indeces.lastIndexSubtrahend]) || defaultValue;
+
+export const last = <T>(array: NullableArray<T>) =>
+  lastOrDefault(array) || undefined;
+
+export const takeWhile = <T>(
+  array: T[],
+  predicate: (item: T) => boolean
+): T[] => {
+  const items: T[] = [];
+
+  for (const item of array) {
+    if (!predicate(item)) {
+      break;
+    }
+
+    items.push(item);
+  }
+
+  return items;
+};
+
+export const takeWhileAll = <T>(
+  array: T[],
+  predicate: (current: T[]) => boolean
+): T[] => {
+  const result: T[] = [];
+
+  for (let index = 0; index < array.length; index += 1) {
+    result.push(array[index]);
+
+    if (!predicate(result)) {
+      result.pop();
+      break;
+    }
+  }
+
+  return result;
+};
 
 export const distinct = <T>(...items: T[]): T[] =>
   items.filter((value: T, index: number, self: T[]) => {

src/lib/cli.ts

@@ -40,7 +40,7 @@ const runCommand = (command: CommandDeclaration, options: OptionMap) => {
     const message = [`Excuting: router ${chalk.bold(command.fullName)}`];
 
     if (any(command.args)) {
-      message.push(`with options ${command.args.join(" ")}`);
+      message.push(` with options '${command.args.join(" ")}'`);
     }
 
     message.push(" ...");

src/lib/commands/jobs/list.ts

@@ -1,10 +1,43 @@
+import cron from "cron-parser";
+import { table } from "table";
+import { isEmpty } from "../../arrayHelper";
+import { ScheduledItem } from "../../../types";
+import { parse } from "../../scheduledItemParser";
 import ssh from "../../ssh";
 import { create } from "../../../models/command";
 
 const description = "Lists existing cron jobs";
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const asTabular = (data: ScheduledItem[]): any[] => {
+  if (isEmpty(data)) return [];
+
+  const tableValues = data.map(x => {
+    const values = Object.values(x);
+    const expression = cron.parseExpression(x.cronExpression);
+    values.push(expression.hasNext() ? expression.next() : "");
+    return values;
+  });
+
+  const headings = Object.getOwnPropertyNames(data[0]);
+  headings.push("next run");
+
+  tableValues.unshift(headings);
+
+  return tableValues;
+};
+
 const run = () => {
-  ssh.execute("cru l");
+  const result = ssh.execute("cru l", { silent: true });
+
+  const parsed = result.stdout
+    .split("\n")
+    .map(x => parse(x))
+    .filter(x => x.id);
+
+  const tabularData = asTabular(parsed);
+  console.log(parsed);
+  console.log(table(tabularData));
 };
 
 export default create({ description, run });

src/lib/scheduledItemParser.ts

@@ -0,0 +1,39 @@
+import { ScheduledItem } from "../types";
+import { takeWhile, takeWhileAll } from "./arrayHelper";
+
+const idMarker = "#";
+
+const parseCronExpression = (row: string[]): [string, string[]] => {
+  const result = takeWhileAll(row, x => x.filter(z => z === " ").length < 5);
+  const remainder = row.slice(result.length + 1);
+
+  return [result.join("").trim(), remainder];
+};
+
+const parseCommand = (row: string[]): [string, string[]] => {
+  const result = takeWhile(row, x => x !== idMarker);
+  const remainder = row.slice(result.length + 1);
+
+  return [result.join("").trim(), remainder];
+};
+
+const parseId = (row: string[]): string => {
+  return row
+    .join("")
+    .replace(new RegExp(`${idMarker}`, "g"), "")
+    .trim();
+};
+
+export const parse = (row: string): ScheduledItem => {
+  const [cronExpression, cronRemainder] = parseCronExpression([...row]);
+  const [command, commandRemainder] = parseCommand(cronRemainder);
+  const id = parseId(commandRemainder);
+
+  const item: ScheduledItem = {
+    id,
+    command,
+    cronExpression
+  };
+
+  return item;
+};

src/models/scheduledItem.ts

@@ -0,0 +1,7 @@
+import { ScheduledItem } from "../types";
+
+export const empty: ScheduledItem = {
+  id: "empty",
+  cronExpression: "* * * * *",
+  command: ""
+};

src/types/ScheduledItem.ts

@@ -0,0 +1,5 @@
+export interface ScheduledItem {
+  id: string;
+  cronExpression: string;
+  command: string;
+}

src/types/index.ts

@@ -9,4 +9,5 @@ export { ParseResult } from "./ParseResult";
 export { default as PromptType } from "./PromptType";
 export { default as PromptBody } from "./PromptBody";
 export { default as SshConfig } from "./SshConfig";
+export { ScheduledItem } from "./ScheduledItem";
 export { StringComparison } from "./StringComparison";