fix: [expression] apply value equal for arrays, #589

Author: harttle

src/render/operator.ts

@@ -2,23 +2,16 @@ import { isComparable } from '../drop/comparable'
 import { Context } from '../context'
 import { isFunction, toValue } from '../util'
 import { isFalsy, isTruthy } from '../render/boolean'
+import { isArray } from '../util/underscore';
 
 export type UnaryOperatorHandler = (operand: any, ctx: Context) => boolean;
 export type BinaryOperatorHandler = (lhs: any, rhs: any, ctx: Context) => boolean;
 export type OperatorHandler = UnaryOperatorHandler | BinaryOperatorHandler;
 export type Operators = Record<string, OperatorHandler>
 
 export const defaultOperators: Operators = {
-  '==': (l: any, r: any) => {
-    if (isComparable(l)) return l.equals(r)
-    if (isComparable(r)) return r.equals(l)
-    return toValue(l) === toValue(r)
-  },
-  '!=': (l: any, r: any) => {
-    if (isComparable(l)) return !l.equals(r)
-    if (isComparable(r)) return !r.equals(l)
-    return toValue(l) !== toValue(r)
-  },
+  '==': equal,
+  '!=': (l: any, r: any) => !equal(l, r),
   '>': (l: any, r: any) => {
     if (isComparable(l)) return l.gt(r)
     if (isComparable(r)) return r.lt(l)
@@ -48,3 +41,19 @@ export const defaultOperators: Operators = {
   'and': (l: any, r: any, ctx: Context) => isTruthy(toValue(l), ctx) && isTruthy(toValue(r), ctx),
   'or': (l: any, r: any, ctx: Context) => isTruthy(toValue(l), ctx) || isTruthy(toValue(r), ctx)
 }
+
+function equal(lhs: any, rhs: any): boolean {
+  if (isComparable(lhs)) return lhs.equals(rhs)
+  if (isComparable(rhs)) return rhs.equals(lhs)
+  lhs = toValue(lhs)
+  rhs = toValue(rhs)
+  if (isArray(lhs)) {
+    return isArray(rhs) && arrayEqual(lhs, rhs)
+  }
+  return lhs === rhs
+}
+
+function arrayEqual(lhs: any[], rhs: any[]): boolean {
+  if (lhs.length !== rhs.length) return false
+  return !lhs.some((value, i) => !equal(value, rhs[i]))
+}

test/e2e/issues.ts

@@ -400,4 +400,14 @@ describe('Issues', function () {
     const html = await engine.parseAndRender(template, { str })
     expect(html).to.match(/^\s*$/)
   })
+  it('#589 Arrays should compare values', async() => {
+    const engine = new Liquid()
+    const template = `
+    {% assign people1 = "alice, bob, carol" | split: ", " -%}
+    {% assign people2 = "alice, bob, carol" | split: ", " -%}
+    {% if people1 == people2 %}true{%else%}false{% endif %}
+    `;
+    const html = await engine.parseAndRender(template)
+    expect(html).to.contain('true')
+  })
 })

test/unit/render/expression.ts

@@ -53,6 +53,15 @@ describe('Expression', function () {
     it('should return false for "1==2"', async () => {
       expect(await toPromise(create('1==2').evaluate(ctx, false))).to.equal(false)
     })
+    it('should apply deep equal for arrays', async () => {
+      const ctx = new Context({
+        arr1: [1, 2],
+        arr2: [1, 2],
+        arr3: [1, 2, 3],
+      })
+      expect(await toPromise(create('arr1==arr2').evaluate(ctx, false))).to.equal(true)
+      expect(await toPromise(create('arr1==arr3').evaluate(ctx, false))).to.equal(false)
+    })
     it('should return true for "1<2"', async () => {
       expect(await toPromise(create('1<2').evaluate(ctx, false))).to.equal(true)
     })