fix: Date parser returns 31 days for last 30 days date range

Fixes #303

Author: paveltiunov

packages/cubejs-api-gateway/dateParser.js

@@ -19,14 +19,16 @@ module.exports = (dateString, timezone) => {
     const match = dateString.match(/last\s+(\d+)\s+(day|week|month|year|quarter|hour|minute|second)/);
     const span = match[2] === 'week' ? 'isoWeek' : match[2];
     momentRange = [
-      moment.tz(timezone).add(-parseInt(match[1], 10) - 1, match[2]).startOf(span),
-      moment.tz(timezone).add(-1, match[2]).endOf(span)
+      moment.tz(timezone).startOf(span).add(-parseInt(match[1], 10), match[2]),
+      moment.tz(timezone).endOf(span).add(-1, match[2])
     ];
   } else if (dateString.match(/today/)) {
     momentRange = [moment.tz(timezone).startOf('day'), moment.tz(timezone).endOf('day')];
   } else if (dateString.match(/yesterday/)) {
-    const yesterday = moment.tz(timezone).add(-1, 'day');
-    momentRange = [moment(yesterday).startOf('day'), moment(yesterday).endOf('day')];
+    momentRange = [
+      moment.tz(timezone).startOf('day').add(-1, 'day'),
+      moment.tz(timezone).endOf('day').add(-1, 'day')
+    ];
   } else {
     const results = chrono.parse(dateString);
     if (!results) {

packages/cubejs-api-gateway/dateParser.test.js

@@ -9,10 +9,26 @@ describe(`dateParser`, () => {
     );
   });
 
+  test(`last 1 day`, () => {
+    expect(dateParser('last 1 day', 'UTC')).toStrictEqual(
+      [dateParser('yesterday', 'UTC')[0], dateParser('yesterday', 'UTC')[1]]
+    );
+  });
+
+  test(`today`, () => {
+    const start = new Date();
+    const end = new Date();
+    start.setUTCHours(0, 0, 0, 0);
+    end.setUTCHours(23, 59, 59, 999);
+    expect(dateParser('today', 'UTC')).toStrictEqual(
+      [start.toISOString().replace('Z', ''), end.toISOString().replace('Z', '')]
+    );
+  });
+
   test(`last 6 hours`, () => {
     expect(dateParser('last 6 hours', 'UTC')).toStrictEqual(
       [
-        new Date((Math.floor(new Date().getTime() / (1000 * 60 * 60)) - 7) * (1000 * 60 * 60)).toISOString().replace('Z', ''),
+        new Date((Math.floor(new Date().getTime() / (1000 * 60 * 60)) - 6) * (1000 * 60 * 60)).toISOString().replace('Z', ''),
         new Date((Math.floor(new Date().getTime() / (1000 * 60 * 60))) * (1000 * 60 * 60) - 1).toISOString().replace('Z', '')
       ]
     );