fix: Format-agnostic time parsing

Closes #916

client/src/components/DueDateEditStep/DueDateEditStep.jsx

@@ -7,6 +7,7 @@ import { useDidUpdate, useToggle } from '../../lib/hooks';
 import { Input, Popup } from '../../lib/custom-ui';
 
 import { useForm } from '../../hooks';
+import parseTime from '../../utils/parse-time';
 
 import styles from './DueDateEditStep.module.scss';
 
@@ -66,10 +67,7 @@ const DueDateEditStep = React.memo(({ defaultValue, onUpdate, onBack, onClose })
       return;
     }
 
-    const value = t('format:dateTime', {
-      postProcess: 'parseDate',
-      value: `${data.date} ${data.time}`,
-    });
+    const value = parseTime(data.time, nullableDate);
 
     if (Number.isNaN(value.getTime())) {
       timeField.current.select();
@@ -81,7 +79,7 @@ const DueDateEditStep = React.memo(({ defaultValue, onUpdate, onBack, onClose })
     }
 
     onClose();
-  }, [defaultValue, onUpdate, onClose, data, nullableDate, t]);
+  }, [defaultValue, onUpdate, onClose, data, nullableDate]);
 
   const handleClearClick = useCallback(() => {
     if (defaultValue) {

client/src/utils/parse-time.js

@@ -0,0 +1,102 @@
+import parseDate from 'date-fns/parse';
+
+const TIME_REGEX =
+  /^((\d{1,2})((:|\.)?(\d{1,2}))?)(a|p|(am|a\.m\.|midnight|mi|pm|p\.m\.|noon|n))?$/;
+
+const ALTERNATIVE_AM_MERIDIEMS_SET = new Set(['am', 'a.m.', 'midnight', 'mi']);
+const ALTERNATIVE_PM_MERIDIEMS_SET = new Set(['pm', 'p.m.', 'noon', 'n']);
+
+const TimeFormats = {
+  TWENTY_FOUR_HOUR: 'twentyFourHour',
+  TWELVE_HOUR: 'twelveHour',
+};
+
+const PATTERNS_GROUPS_BY_TIME_FORMAT = {
+  [TimeFormats.TWENTY_FOUR_HOUR]: {
+    byNumbersTotal: {
+      1: ['H'],
+      2: ['HH'],
+      3: ['Hmm'],
+      4: ['HHmm'],
+    },
+    withDelimiter: ['H:m', 'H:mm', 'HH:m', 'HH:mm'],
+  },
+  [TimeFormats.TWELVE_HOUR]: {
+    byNumbersTotal: {
+      1: ['haaaaa'],
+      2: ['hhaaaaa'],
+      3: ['hmmaaaaa'],
+      4: ['hhmmaaaaa'],
+    },
+    withDelimiter: ['h:maaaaa', 'h:mmaaaaa', 'hh:maaaaa', 'hh:mmaaaaa'],
+  },
+};
+
+const INVALID_DATE = new Date('invalid-date');
+
+const normalizeDelimeter = (delimeter) => (delimeter === '.' ? ':' : delimeter);
+
+const normalizeMeridiem = (meridiem, alternativeMeridiem) => {
+  if (meridiem && alternativeMeridiem) {
+    if (ALTERNATIVE_AM_MERIDIEMS_SET.has(alternativeMeridiem)) {
+      return 'a';
+    }
+
+    if (ALTERNATIVE_PM_MERIDIEMS_SET.has(alternativeMeridiem)) {
+      return 'p';
+    }
+  }
+
+  return meridiem;
+};
+
+const makeTimeString = (hours, minutes, delimeter, meridiem) => {
+  let timeString = hours;
+  if (delimeter) {
+    timeString += delimeter;
+  }
+  if (minutes) {
+    timeString += minutes;
+  }
+  if (meridiem) {
+    timeString += meridiem;
+  }
+
+  return timeString;
+};
+
+export default (string, referenceDate) => {
+  const match = string.replace(/\s/g, '').toLowerCase().match(TIME_REGEX);
+
+  if (!match) {
+    return INVALID_DATE;
+  }
+
+  const [, hoursAndMinutes, hours, , delimeter, minutes, meridiem, alternativeMeridiem] = match;
+
+  const normalizedDelimeter = normalizeDelimeter(delimeter);
+  const normalizedMeridiem = normalizeMeridiem(meridiem, alternativeMeridiem);
+
+  const timeString = makeTimeString(hours, minutes, normalizedDelimeter, normalizedMeridiem);
+
+  const timeFormat = meridiem ? TimeFormats.TWELVE_HOUR : TimeFormats.TWENTY_FOUR_HOUR;
+  const patternsGroups = PATTERNS_GROUPS_BY_TIME_FORMAT[timeFormat];
+
+  const patterns = delimeter
+    ? patternsGroups.withDelimiter
+    : patternsGroups.byNumbersTotal[hoursAndMinutes.length];
+
+  if (!referenceDate) {
+    referenceDate = new Date(); // eslint-disable-line no-param-reassign
+  }
+
+  for (let i = 0; i < patterns.length; i += 1) {
+    const parsedDate = parseDate(timeString, patterns[i], referenceDate);
+
+    if (!Number.isNaN(parsedDate.getTime())) {
+      return parsedDate;
+    }
+  }
+
+  return INVALID_DATE;
+};