feat: add preserveTimezones option

src/builtin/filters/date.ts

@@ -1,14 +1,21 @@
 import strftime, { TimezoneDate } from '../../util/strftime'
 import { isString, isNumber } from '../../util/underscore'
+import { FilterImpl } from '../../template/filter/filter-impl'
 
-export function date (v: string | Date, arg: string) {
+export function date (this: FilterImpl, v: string | Date, arg: string) {
   let date = v
   if (v === 'now' || v === 'today') {
     date = new Date()
   } else if (isNumber(v)) {
     date = new Date(v * 1000)
   } else if (isString(v)) {
-    date = /^\d+$/.test(v) ? new Date(+v * 1000) : new TimezoneDate(v)
+    if (/^\d+$/.test(v)) {
+      date = new Date(+v * 1000)
+    } else if (this.context.opts.preserveTimezones) {
+      date = new TimezoneDate(v)
+    } else {
+      date = new Date(v)
+    }
   }
   return isValidDate(date) ? strftime(date, arg) : v
 }

src/liquid-options.ts

@@ -37,6 +37,8 @@ export interface LiquidOptions {
   outputDelimiterLeft?: string;
   /** The right delimiter for liquid outputs. **/
   outputDelimiterRight?: string;
+  /** Whether input strings to date filter preserve the given timezone **/
+  preserveTimezones?: boolean;
   /** Whether `trim*Left`/`trim*Right` is greedy. When set to `true`, all consecutive blank characters including `\n` will be trimed regardless of line breaks. Defaults to `true`. */
   greedy?: boolean;
   /** `fs` is used to override the default file-system module with a custom implementation. */
@@ -69,6 +71,7 @@ export interface NormalizedFullOptions extends NormalizedOptions {
   tagDelimiterRight: string;
   outputDelimiterLeft: string;
   outputDelimiterRight: string;
+  preserveTimezones: boolean;
   greedy: boolean;
   globals: object;
   keepOutputType: boolean;
@@ -89,6 +92,7 @@ export const defaultOptions: NormalizedFullOptions = {
   tagDelimiterRight: '%}',
   outputDelimiterLeft: '{{',
   outputDelimiterRight: '}}',
+  preserveTimezones: false,
   strictFilters: false,
   strictVariables: false,
   lenientIf: false,

test/integration/builtin/filters/date.ts

@@ -1,3 +1,4 @@
+import { LiquidOptions } from '../../../../src/liquid-options'
 import { test } from '../../../stub/render'
 
 describe('filters/date', function () {
@@ -14,17 +15,21 @@ describe('filters/date', function () {
   it('should parse as Date when given a timezoneless string', function () {
     return test('{{ "1991-02-22T00:00:00" | date: "%Y-%m-%dT%H:%M:%S"}}', '1991-02-22T00:00:00')
   })
-  it('should not change the timezone between input and output', function () {
-    return test('{{ "1990-12-31T23:00:00Z" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00')
-  })
-  it('should apply numeric timezone offset (0)', function () {
-    return test('{{ "1990-12-31T23:00:00+00:00" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00')
-  })
-  it('should apply numeric timezone offset (-1)', function () {
-    return test('{{ "1990-12-31T23:00:00-01:00" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00')
-  })
-  it('should apply numeric timezone offset (+2.30)', function () {
-    return test('{{ "1990-12-31T23:00:00+02:30" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00')
+  describe('when preserveTimezones is enabled', function () {
+    const opts: LiquidOptions = { preserveTimezones: true };
+
+    it('should not change the timezone between input and output', function () {
+      return test('{{ "1990-12-31T23:00:00Z" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00', undefined, opts)
+    })
+    it('should apply numeric timezone offset (0)', function () {
+      return test('{{ "1990-12-31T23:00:00+00:00" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00', undefined, opts)
+    })
+    it('should apply numeric timezone offset (-1)', function () {
+      return test('{{ "1990-12-31T23:00:00-01:00" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00', undefined, opts)
+    })
+    it('should apply numeric timezone offset (+2.30)', function () {
+      return test('{{ "1990-12-31T23:00:00+02:30" | date: "%Y-%m-%dT%H:%M:%S"}}', '1990-12-31T23:00:00', undefined, opts)
+    })
   })
   it('should render string as string if not valid', function () {
     return test('{{ "foo" | date: "%Y"}}', 'foo')

test/stub/render.ts

@@ -1,16 +1,17 @@
 import { Liquid } from '../../src/liquid'
+import { LiquidOptions } from '../../src/liquid-options'
 import { expect } from 'chai'
 
 export const liquid = new Liquid()
 
-export function render (src: string, ctx?: object) {
-  return liquid.parseAndRender(src, ctx)
+export function render (src: string, ctx?: object, opts?: LiquidOptions) {
+  return liquid.parseAndRender(src, ctx, opts)
 }
 
-export async function test (src: string, ctx: object | string, dst?: string) {
+export async function test (src: string, ctx: object | string, dst?: string, opts?: LiquidOptions) {
   if (dst === undefined) {
     dst = ctx as string
     ctx = {}
   }
-  return expect(await render(src, ctx as object)).to.equal(dst)
+  return expect(await render(src, ctx as object, opts)).to.equal(dst)
 }