feat: support Jekyll style where, #768

src/drop/blank-drop.ts

@@ -8,4 +8,7 @@ export class BlankDrop extends EmptyDrop {
     if (isString(value)) return /^\s*$/.test(value)
     return super.equals(value)
   }
+  static is (value: unknown) {
+    return value instanceof BlankDrop
+  }
 }

src/drop/empty-drop.ts

@@ -25,4 +25,7 @@ export class EmptyDrop extends Drop implements Comparable {
   public valueOf () {
     return ''
   }
+  static is (value: unknown) {
+    return value instanceof EmptyDrop
+  }
 }

src/filters/array.ts

@@ -1,8 +1,9 @@
 import { toArray, argumentsToValue, toValue, stringify, caseInsensitiveCompare, isArray, isNil, last as arrayLast } from '../util'
-import { equals, evalToken, isTruthy } from '../render'
+import { arrayIncludes, equals, evalToken, isTruthy } from '../render'
 import { Value, FilterImpl } from '../template'
 import { Tokenizer } from '../parser'
 import type { Scope } from '../context'
+import { EmptyDrop } from '../drop'
 
 export const join = argumentsToValue(function (this: FilterImpl, v: any[], arg: string) {
   const array = toArray(v)
@@ -124,9 +125,12 @@ export function * where<T extends object> (this: FilterImpl, arr: T[], property:
   for (const item of arr) {
     values.push(yield evalToken(token, this.context.spawn(item)))
   }
+  const matcher = this.context.opts.jekyllWhere
+    ? (v: any) => EmptyDrop.is(expected) ? equals(v, expected) : (isArray(v) ? arrayIncludes(v, expected) : equals(v, expected))
+    : (v: any) => equals(v, expected)
   return arr.filter((_, i) => {
     if (expected === undefined) return isTruthy(values[i], this.context)
-    return equals(values[i], expected)
+    return matcher(values[i])
   })
 }
 

src/liquid-options.ts

@@ -22,6 +22,8 @@ export interface LiquidOptions {
   relativeReference?: boolean;
   /** Use jekyll style include, pass parameters to `include` variable of current scope. Defaults to `false`. */
   jekyllInclude?: boolean;
+  /** Use jekyll style where filter, enables array item match. Defaults to `false`. */
+  jekyllWhere?: boolean;
   /** Add a extname (if filepath doesn't include one) before template file lookup. Eg: setting to `".html"` will allow including file by basename. Defaults to `""`. */
   extname?: string;
   /** Whether or not to cache resolved templates. Defaults to `false`. */

src/render/operator.ts

@@ -58,3 +58,7 @@ function arrayEquals (lhs: any[], rhs: any[]): boolean {
   if (lhs.length !== rhs.length) return false
   return !lhs.some((value, i) => !equals(value, rhs[i]))
 }
+
+export function arrayIncludes (arr: any[], item: any): boolean {
+  return arr.some(value => equals(value, item))
+}