feat: pop/shift/unshift filters from Jekyll

docs/source/_data/sidebar.yml

@@ -51,6 +51,7 @@ filters:
   modulo: modulo.html
   newline_to_br: newline_to_br.html
   plus: plus.html
+  pop: pop.html
   push: push.html
   prepend: prepend.html
   raw: raw.html
@@ -63,6 +64,7 @@ filters:
   reverse: reverse.html
   round: round.html
   rstrip: rstrip.html
+  shift: shift.html
   size: size.html
   slice: slice.html
   sort: sort.html
@@ -76,6 +78,7 @@ filters:
   truncate: truncate.html
   truncatewords: truncatewords.html
   uniq: uniq.html
+  unshift: unshift.html
   upcase: upcase.html
   url_decode: url_decode.html
   url_encode: url_encode.html

docs/source/filters/overview.md

@@ -12,7 +12,7 @@ Categories | Filters
 Math | plus, minus, modulo, times, floor, ceil, round, divided_by, abs, at_least, at_most
 String | append, prepend, capitalize, upcase, downcase, strip, lstrip, rstrip, strip_newlines, split, replace, replace_first, replace_last,remove, remove_first, remove_last, truncate, truncatewords
 HTML/URI | escape, escape_once, url_encode, url_decode, strip_html, newline_to_br
-Array | slice, map, sort, sort_natural, uniq, where, first, last, join, reverse, concat, compact, size, push
+Array | slice, map, sort, sort_natural, uniq, where, first, last, join, reverse, concat, compact, size, push, pop, shift, unshift
 Date | date
 Misc | default, json, raw
 

docs/source/filters/pop.md

@@ -0,0 +1,24 @@
+---
+title: pop
+---
+
+{% since %}v10.11.0{% endsince %}
+
+Pop an element from the array. It's NON-DESTRUCTIVE, i.e. it does not mutate the array, but rather make a copy and mutate that.
+
+Input
+```liquid
+{% assign fruits = "apples, oranges, peaches" | split: ", " %}
+
+{% assign everything = fruits | pop %}
+
+{% for item in everything %}
+- {{ item }}
+{% endfor %}
+```
+
+Output
+```text
+- apples
+- oranges
+```

docs/source/filters/shift.md

@@ -0,0 +1,24 @@
+---
+title: shift
+---
+
+{% since %}v10.11.0{% endsince %}
+
+Shift an element from the array. It's NON-DESTRUCTIVE, i.e. it does not mutate the array, but rather make a copy and mutate that.
+
+Input
+```liquid
+{% assign fruits = "apples, oranges, peaches" | split: ", " %}
+
+{% assign everything = fruits | shift %}
+
+{% for item in everything %}
+- {{ item }}
+{% endfor %}
+```
+
+Output
+```text
+- oranges
+- peaches
+```

docs/source/filters/unshift.md

@@ -0,0 +1,25 @@
+---
+title: unshift
+---
+
+{% since %}v10.11.0{% endsince %}
+
+Unshift an element to the front of the array. It's NON-DESTRUCTIVE, i.e. it does not mutate the array, but rather make a copy and mutate that.
+
+Input
+```liquid
+{% assign fruits = "oranges, peaches" | split: ", " %}
+
+{% assign everything = fruits | unshift: "apples" %}
+
+{% for item in everything %}
+- {{ item }}
+{% endfor %}
+```
+
+Output
+```text
+- apples
+- oranges
+- peaches
+```

docs/source/zh-cn/filters/overview.md

@@ -12,7 +12,7 @@ LiquidJS 共支持 40+ 个过滤器，可以分为如下几类：
 数学 | plus, minus, modulo, times, floor, ceil, round, divided_by, abs, at_least, at_most
 字符串 | append, prepend, capitalize, upcase, downcase, strip, lstrip, rstrip, strip_newlines, split, replace, replace_first, replace_last, remove, remove_first, remove_last, truncate, truncatewords
 HTML/URI | escape, escape_once, url_encode, url_decode, strip_html, newline_to_br
-数组 | slice, map, sort, sort_natural, uniq, wheres, first, last, join, reverse, concat, compact, size, push
+数组 | slice, map, sort, sort_natural, uniq, wheres, first, last, join, reverse, concat, compact, size, push, pop, shift, unshift
 日期 | date
 其他 | default, json
 

docs/source/zh-cn/filters/pop.md

@@ -0,0 +1,24 @@
+---
+title: pop
+---
+
+{% since %}v10.11.0{% endsince %}
+
+从数组末尾弹出一个元素。注意该操作不会改变原数组，而是在一份拷贝上操作。
+
+输入
+```liquid
+{% assign fruits = "apples, oranges, peaches" | split: ", " %}
+
+{% assign everything = fruits | pop %}
+
+{% for item in everything %}
+- {{ item }}
+{% endfor %}
+```
+
+输出
+```text
+- apples
+- oranges
+```

docs/source/zh-cn/filters/shift.md

@@ -0,0 +1,24 @@
+---
+title: shift
+---
+
+{% since %}v10.11.0{% endsince %}
+
+从数组头部弹出一个元素。注意该操作不会改变原数组，而是在一份拷贝上操作。
+
+输入
+```liquid
+{% assign fruits = "apples, oranges, peaches" | split: ", " %}
+
+{% assign everything = fruits | shift %}
+
+{% for item in everything %}
+- {{ item }}
+{% endfor %}
+```
+
+输出
+```text
+- oranges
+- peaches
+```

docs/source/zh-cn/filters/unshift.md

@@ -0,0 +1,25 @@
+---
+title: unshift
+---
+
+{% since %}v10.11.0{% endsince %}
+
+往数组头部添加一个元素。注意该操作不会改变原数组，而是在一份拷贝上操作。
+
+输入
+```liquid
+{% assign fruits = "oranges, peaches" | split: ", " %}
+
+{% assign everything = fruits | unshift: "apples" %}
+
+{% for item in everything %}
+- {{ item }}
+{% endfor %}
+```
+
+输出
+```text
+- apples
+- oranges
+- peaches
+```

src/filters/array.ts

@@ -11,7 +11,7 @@ export const reverse = argumentsToValue((v: any[]) => [...toArray(v)].reverse())
 
 export function * sort<T> (this: FilterImpl, arr: T[], property?: string): IterableIterator<unknown> {
   const values: [T, string | number][] = []
-  for (const item of toArray(toValue(arr))) {
+  for (const item of toArray(arr)) {
     values.push([
       item,
       property ? yield this.context._getFromScope(item, stringify(property).split('.'), false) : item
@@ -25,7 +25,6 @@ export function * sort<T> (this: FilterImpl, arr: T[], property?: string): Itera
 }
 
 export function sort_natural<T> (input: T[], property?: string) {
-  input = toValue(input)
   const propertyString = stringify(property)
   const compare = property === undefined
     ? caseInsensitiveCompare
@@ -37,7 +36,7 @@ export const size = (v: string | any[]) => (v && v.length) || 0
 
 export function * map (this: FilterImpl, arr: Scope[], property: string): IterableIterator<unknown> {
   const results = []
-  for (const item of toArray(toValue(arr))) {
+  for (const item of toArray(arr)) {
     results.push(yield this.context._getFromScope(item, stringify(property), false))
   }
   return results
@@ -45,7 +44,7 @@ export function * map (this: FilterImpl, arr: Scope[], property: string): Iterab
 
 export function * sum (this: FilterImpl, arr: Scope[], property?: string): IterableIterator<unknown> {
   let sum = 0
-  for (const item of toArray(toValue(arr))) {
+  for (const item of toArray(arr)) {
     const data = Number(property ? yield this.context._getFromScope(item, stringify(property), false) : item)
     sum += Number.isNaN(data) ? 0 : data
   }
@@ -53,20 +52,35 @@ export function * sum (this: FilterImpl, arr: Scope[], property?: string): Itera
 }
 
 export function compact<T> (this: FilterImpl, arr: T[]) {
-  arr = toValue(arr)
   return toArray(arr).filter(x => !isNil(toValue(x)))
 }
 
 export function concat<T1, T2> (v: T1[], arg: T2[] = []): (T1 | T2)[] {
-  v = toValue(v)
-  arg = toArray(arg).map(v => toValue(v))
-  return toArray(v).concat(arg)
+  return toArray(v).concat(toArray(arg))
 }
 
 export function push<T> (v: T[], arg: T): T[] {
   return concat(v, [arg])
 }
 
+export function unshift<T> (v: T[], arg: T): T[] {
+  const clone = [...toArray(v)]
+  clone.unshift(arg)
+  return clone
+}
+
+export function pop<T> (v: T[]): T[] {
+  const clone = [...toArray(v)]
+  clone.pop()
+  return clone
+}
+
+export function shift<T> (v: T[]): T[] {
+  const clone = [...toArray(v)]
+  clone.shift()
+  return clone
+}
+
 export function slice<T> (v: T[] | string, begin: number, length = 1): T[] | string {
   v = toValue(v)
   if (isNil(v)) return []
@@ -77,7 +91,7 @@ export function slice<T> (v: T[] | string, begin: number, length = 1): T[] | str
 
 export function * where<T extends object> (this: FilterImpl, arr: T[], property: string, expected?: any): IterableIterator<unknown> {
   const values: unknown[] = []
-  arr = toArray(toValue(arr))
+  arr = toArray(arr)
   for (const item of arr) {
     values.push(yield this.context._getFromScope(item, stringify(property).split('.'), false))
   }

src/tags/for.ts

@@ -1,5 +1,5 @@
 import { Hash, ValueToken, Liquid, Tag, evalToken, Emitter, TagToken, TopLevelToken, Context, Template, ParseStream } from '..'
-import { toEnumerable } from '../util/collection'
+import { toEnumerable } from '../util'
 import { ForloopDrop } from '../drop/forloop-drop'
 
 const MODIFIERS = ['offset', 'limit', 'reversed']

src/tags/tablerow.ts

@@ -1,4 +1,4 @@
-import { toEnumerable } from '../util/collection'
+import { toEnumerable } from '../util'
 import { ValueToken, Liquid, Tag, evalToken, Emitter, Hash, TagToken, TopLevelToken, Context, Template, ParseStream } from '..'
 import { TablerowloopDrop } from '../drop/tablerowloop-drop'
 

src/util/collection.ts

@@ -1,16 +0,0 @@
-import { isNil, isString, isObject, isArray, isIterable, toValue } from './underscore'
-
-export function toEnumerable<T = unknown> (val: any): T[] {
-  val = toValue(val)
-  if (isArray(val)) return val
-  if (isString(val) && val.length > 0) return [val] as unknown as T[]
-  if (isIterable(val)) return Array.from(val)
-  if (isObject(val)) return Object.keys(val).map((key) => [key, val[key]]) as unknown as T[]
-  return []
-}
-
-export function toArray (val: any) {
-  if (isNil(val)) return []
-  if (isArray(val)) return val
-  return [ val ]
-}

src/util/index.ts

@@ -6,7 +6,6 @@ export * from './underscore'
 export * from './operator-trie'
 export * from './type-guards'
 export * from './async'
-export * from './collection'
 export * from './strftime'
 export * from './liquid-date'
 export * from './timezone-date'

src/util/underscore.ts

@@ -46,6 +46,22 @@ export function stringify (value: any): string {
   return String(value)
 }
 
+export function toEnumerable<T = unknown> (val: any): T[] {
+  val = toValue(val)
+  if (isArray(val)) return val
+  if (isString(val) && val.length > 0) return [val] as unknown as T[]
+  if (isIterable(val)) return Array.from(val)
+  if (isObject(val)) return Object.keys(val).map((key) => [key, val[key]]) as unknown as T[]
+  return []
+}
+
+export function toArray (val: any) {
+  val = toValue(val)
+  if (isNil(val)) return []
+  if (isArray(val)) return val
+  return [ val ]
+}
+
 export function toValue (value: any): any {
   return (value instanceof Drop && isFunction(value.valueOf)) ? value.valueOf() : value
 }

test/integration/filters/array.spec.ts

@@ -158,10 +158,53 @@ describe('filters/array', function () {
       await test('{{ undefinedValue | push: arg | join: "," }}', scope, 'foo')
       await test('{{ nullValue | push: arg | join: "," }}', scope, 'foo')
     })
-    it('should ignore nil right value', async () => {
-      const scope = { nullValue: null }
-      await test('{{ nullValue | push | join: "," }}', scope, '')
-      await test('{{ nullValue | push: nil | join: "," }}', scope, '')
+    it('should support nil right value', async () => {
+      const scope = { nullValue: [] }
+      await test('{{ nullValue | push | size }}', scope, '1')
+      await test('{{ nullValue | push: nil | size }}', scope, '1')
+    })
+  })
+
+  describe('pop', () => {
+    it('should support pop', async () => {
+      const scope = { val: ['hey', 'you'] }
+      await test('{{ val | pop | join: "," }}', scope, 'hey')
+    })
+    it('should not change original array', async () => {
+      const scope = { val: ['hey', 'you'] }
+      await test('{{ val | pop | join: "," }} {{ val| join: "," }}', scope, 'hey hey,you')
+    })
+    it('should support nil left value', async () => {
+      await test('{{ notDefined | pop | join: "," }}', {}, '')
+    })
+  })
+
+  describe('unshift', () => {
+    it('should support unshift', async () => {
+      const scope = { val: ['you'] }
+      await test('{{ val | unshift: "hey" | join: ", " }}', scope, 'hey, you')
+    })
+    it('should not change original array', async () => {
+      const scope = { val: ['you'] }
+      await test('{{ val | unshift: "hey" | join: "," }} {{ val | join: "," }}', scope, 'hey,you you')
+    })
+    it('should support nil right value', async () => {
+      const scope = { val: [] }
+      await test('{{ val | unshift: nil | size }}', scope, '1')
+    })
+  })
+
+  describe('shift', () => {
+    it('should support pop', async () => {
+      const scope = { val: ['hey', 'you'] }
+      await test('{{ val | shift }}', scope, 'you')
+    })
+    it('should not change original array', async () => {
+      const scope = { val: ['hey', 'you'] }
+      await test('{{ val | shift }} {{ val | join: ","}}', scope, 'you hey,you')
+    })
+    it('should support nil left value', async () => {
+      await test('{{ notDefined | pop }}', {}, '')
     })
   })
 

test/integration/tags/for.spec.ts

@@ -63,7 +63,7 @@ describe('tags/for', function () {
     const engine = new Liquid({ strictVariables: true })
     const src = '{% assign hello = "hello,world" | split: "," | concat: null %}{% for i in hello %}{{ i }},{% endfor %}'
     const html = await engine.parseAndRender(src, scope)
-    return expect(html).toBe('hello,world,,')
+    return expect(html).toBe('hello,world,')
   })
   describe('illegal', function () {
     it('should reject when for not closed', function () {