Fix top in json-logic-engine

Author: TotalTechGeek

asyncLogic.js

@@ -212,24 +212,23 @@ class AsyncLogicEngine {
     this.fallback.truthy = this.truthy
     // @ts-ignore
     this.fallback.allowFunctions = this.allowFunctions
-    if (top) {
-      const constructedFunction = await buildAsync(logic, { engine: this, above, async: true, state: {} })
-
-      const result = declareSync((...args) => {
-        if (top === true) {
-          try {
-            const result = typeof constructedFunction === 'function' ? constructedFunction(...args) : constructedFunction
-            return Promise.resolve(result)
-          } catch (err) {
-            return Promise.reject(err)
-          }
+    const constructedFunction = await buildAsync(logic, { engine: this, above, async: true })
+
+    const result = declareSync((...args) => {
+      if (top === true) {
+        try {
+          const result = typeof constructedFunction === 'function' ? constructedFunction(...args) : constructedFunction
+          return Promise.resolve(result)
+        } catch (err) {
+          return Promise.reject(err)
         }
+      }
 
-        return typeof constructedFunction === 'function' ? constructedFunction(...args) : constructedFunction
-      }, top !== true && isSync(constructedFunction))
-      return typeof constructedFunction === 'function' || top === true ? result : constructedFunction
-    }
-    return logic
+      return typeof constructedFunction === 'function' ? constructedFunction(...args) : constructedFunction
+    }, top !== true && isSync(constructedFunction))
+
+    if (top === false && constructedFunction.deterministic) return result()
+    return (typeof constructedFunction === 'function' || top === true) ? result : constructedFunction
   }
 }
 export default AsyncLogicEngine

compiler.js

@@ -326,6 +326,7 @@ function processBuiltString (method, str, buildState) {
   return Object.assign(
     (typeof globalThis !== 'undefined' ? globalThis : global).eval(final)(values, methods, notTraversed, asyncIterators, engine, above, coerceArray, precoerceNumber, assertSize, compareCheck), {
       [Sync]: !buildState.asyncDetected,
+      deterministic: !str.includes('('),
       aboveDetected: typeof str === 'string' && str.includes(', above')
     })
 }

general.test.js

@@ -134,6 +134,15 @@ describe('Various Test Cases', () => {
     for (const engine of [...normalEngines, ...permissiveEngines]) await testEngine(engine, { var: 'toString' }, 'hello', null)
   })
 
+  it('is able to return the constant value', async () => {
+    for (const engine of [...normalEngines, ...permissiveEngines]) {
+      const items = [1, 'hello', [1, 2], [{}]]
+      for (const item of items) {
+        if (JSON.stringify(await engine.build(item, { top: false })) !== JSON.stringify(item)) throw new Error('Should have returned the same value, ' + item)
+      }
+    }
+  })
+
   it('is able to return functions if enabled', async () => {
     try {
       for (const engine of [...normalEngines, ...permissiveEngines]) {

logic.js

@@ -184,12 +184,9 @@ class LogicEngine {
    */
   build (logic, options = {}) {
     const { above = [], top = true } = options
-    if (top) {
-      const constructedFunction = build(logic, { state: {}, engine: this, above })
-      if (typeof constructedFunction === 'function' || top === true) return (...args) => typeof constructedFunction === 'function' ? constructedFunction(...args) : constructedFunction
-      return constructedFunction
-    }
-    return logic
+    const constructedFunction = build(logic, { engine: this, above })
+    if (top === false && constructedFunction.deterministic) return constructedFunction()
+    return constructedFunction
   }
 }
 export default LogicEngine

package.json

@@ -1,6 +1,6 @@
 {
   "name": "json-logic-engine",
-  "version": "5.0.0-7",
+  "version": "5.0.0-8",
   "description": "Construct complex rules with JSON & process them.",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",