From ba4f7d2ceba80f386e39d8da2fb9871d4a749ea4 Mon Sep 17 00:00:00 2001
From: Valentin Valls <valentin.valls@esrf.fr>
Date: Thu, 25 Aug 2022 23:15:16 +0200
Subject: [PATCH] Rework 'parseDuration' as a pure duration parsing

---
 src/diagrams/gantt/ganttDb.js      | 56 ++++++++++++++----------------
 src/diagrams/gantt/ganttDb.spec.js | 17 ++++-----
 2 files changed, 36 insertions(+), 37 deletions(-)

diff --git a/src/diagrams/gantt/ganttDb.js b/src/diagrams/gantt/ganttDb.js
index 996f22e79..f6a526759 100644
--- a/src/diagrams/gantt/ganttDb.js
+++ b/src/diagrams/gantt/ganttDb.js
@@ -231,37 +231,30 @@ const getStartDate = function (prevTime, dateFormat, str) {
 };
 
 /**
- * Parse a duration as an absolute date.
+ * Parse a string as a moment duration.
  *
- * @param durationStr A string representing a duration
- * @param relativeTime The moment when this duration starts
- * @returns The date of the end of the duration.
+ * The string have to be compound by a value and a shorthand duration unit. For example `5d`
+ * representes 5 days.
+ *
+ * Shorthand unit supported are:
+ *
+ * - `y` for years
+ * - `M` for months
+ * - `w` for weeks
+ * - `d` for days
+ * - `h` for hours
+ * - `s` for seconds
+ * - `ms` for milliseconds
+ *
+ * @param {string} str - A string representing the duration.
+ * @returns {moment.Duration} A moment duration, including an invalid moment for invalid input string.
  */
-const parseDuration = function (durationStr, relativeTime) {
-  const durationStatement = /^(\d+(?:\.\d+)?)([wdhms]|ms)$/.exec(durationStr.trim());
-  if (durationStatement !== null) {
-    switch (durationStatement[2]) {
-      case 'ms':
-        relativeTime.add(durationStatement[1], 'milliseconds');
-        break;
-      case 's':
-        relativeTime.add(durationStatement[1], 'seconds');
-        break;
-      case 'm':
-        relativeTime.add(durationStatement[1], 'minutes');
-        break;
-      case 'h':
-        relativeTime.add(durationStatement[1], 'hours');
-        break;
-      case 'd':
-        relativeTime.add(durationStatement[1], 'days');
-        break;
-      case 'w':
-        relativeTime.add(durationStatement[1], 'weeks');
-        break;
-    }
+const parseDuration = function (str) {
+  const statement = /^(\d+(?:\.\d+)?)([yMwdhms]|ms)$/.exec(str.trim());
+  if (statement !== null) {
+    return moment.duration(Number.parseFloat(statement[1]), statement[2]);
   }
-  return relativeTime.toDate();
+  return moment.duration.invalid();
 };
 
 const getEndDate = function (prevTime, dateFormat, str, inclusive) {
@@ -277,7 +270,12 @@ const getEndDate = function (prevTime, dateFormat, str, inclusive) {
     return mDate.toDate();
   }
 
-  return parseDuration(str, moment(prevTime));
+  const endTime = moment(prevTime);
+  const duration = parseDuration(str);
+  if (duration.isValid()) {
+    endTime.add(duration);
+  }
+  return endTime.toDate();
 };
 
 let taskCnt = 0;
diff --git a/src/diagrams/gantt/ganttDb.spec.js b/src/diagrams/gantt/ganttDb.spec.js
index e3622a5fb..4d1c3860b 100644
--- a/src/diagrams/gantt/ganttDb.spec.js
+++ b/src/diagrams/gantt/ganttDb.spec.js
@@ -6,15 +6,16 @@ describe('when using the ganttDb', function () {
     ganttDb.clear();
   });
 
-  describe('when using relative times', function () {
+  describe('when using duration', function () {
     it.each`
-      diff      | date                        | expected
-      ${'1d'}   | ${moment.utc('2019-01-01')} | ${'2019-01-02T00:00:00.000Z'}
-      ${'1w'}   | ${moment.utc('2019-01-01')} | ${'2019-01-08T00:00:00.000Z'}
-      ${'1ms'}  | ${moment.utc('2019-01-01')} | ${'2019-01-01T00:00:00.001Z'}
-      ${'0.1s'} | ${moment.utc('2019-01-01')} | ${'2019-01-01T00:00:00.100Z'}
-    `('should add $diff to $date resulting in $expected', ({ diff, date, expected }) => {
-      expect(ganttDb.parseDuration(diff, date).toISOString()).toEqual(expected);
+      str       | expected
+      ${'1d'}   | ${moment.duration(1, 'd')}
+      ${'2w'}   | ${moment.duration(2, 'w')}
+      ${'1ms'}  | ${moment.duration(1, 'ms')}
+      ${'0.1s'} | ${moment.duration(100, 'ms')}
+      ${'1f'}   | ${moment.duration.invalid()}
+    `('should $str resulting in $expected duration', ({ str, expected }) => {
+      expect(ganttDb.parseDuration(str)).toEqual(expected);
     });
   });