fix: issues in stringify adding parenthesis when needed

Author: josdejong

src/stringify.ts

@@ -1,5 +1,5 @@
 import { isArray } from './is'
-import { extendOperators, operators } from './operators'
+import { extendOperators, leftAssociativeOperators, operators } from './operators'
 import { unquotedPropertyRegex } from './regexps'
 import type {
   JSONPath,
@@ -37,6 +37,9 @@ export const stringify = (query: JSONQuery, options?: JSONQueryStringifyOptions)
   const customOperators = options?.operators ?? []
   const allOperators = extendOperators(operators, customOperators)
   const allOperatorsMap = Object.assign({}, ...allOperators)
+  const allLeftAssociativeOperators = leftAssociativeOperators.concat(
+    customOperators.filter((op) => op.leftAssociative).map((op) => op.op)
+  )
 
   const _stringify = (query: JSONQuery, indent: string, parenthesis = false) =>
     isArray(query)
@@ -73,7 +76,10 @@ export const stringify = (query: JSONQuery, options?: JSONQueryStringifyOptions)
         const childName = child?.[0]
         const precedence = allOperators.findIndex((group) => name in group)
         const childPrecedence = allOperators.findIndex((group) => childName in group)
-        const parenthesis = precedence <= childPrecedence && (index > 0 || name === childName)
+        const parenthesis =
+          precedence < childPrecedence ||
+          (precedence === childPrecedence && index > 0) ||
+          (name === childName && !allLeftAssociativeOperators.includes(op))
 
         return _stringify(child, indent + space, parenthesis)
       })

test-suite/stringify.test.json

@@ -48,11 +48,11 @@
       "category": "operator",
       "description": "should wrap operators with the same precedence in parenthesis when needed",
       "tests": [
-        { "input": ["multiply", 2, 3, 4], "output": "2 * 3 * 4" },
-        { "input": ["multiply", ["multiply", 2, 3], 4], "output": "(2 * 3) * 4" },
+        { "input": ["pow", ["pow", 2, 3], 4], "output": "(2 ^ 3) ^ 4" },
+        { "input": ["pow", 2, ["pow", 3, 4]], "output": "2 ^ (3 ^ 4)" },
+        { "input": ["multiply", ["multiply", 2, 3], 4], "output": "2 * 3 * 4" },
         { "input": ["multiply", 2, ["multiply", 3, 4]], "output": "2 * (3 * 4)" },
-        { "input": ["divide", 2, 3, 4], "output": "2 / 3 / 4" },
-        { "input": ["divide", ["divide", 2, 3], 4], "output": "(2 / 3) / 4" },
+        { "input": ["divide", ["divide", 2, 3], 4], "output": "2 / 3 / 4" },
         { "input": ["divide", 2, ["divide", 3, 4]], "output": "2 / (3 / 4)" },
         { "input": ["divide", ["multiply", 2, 3], 4], "output": "2 * 3 / 4" },
         { "input": ["divide", 2, ["multiply", 3, 4]], "output": "2 / (3 * 4)" },
@@ -62,20 +62,19 @@
           "output": "2 / (3 * 4) / (5 * 6)"
         },
         { "input": ["multiply", ["divide", 2, 3], 4], "output": "2 / 3 * 4" },
-        { "input": ["mod", 2, 3, 4], "output": "2 % 3 % 4" },
-        { "input": ["mod", ["mod", 2, 3], 4], "output": "(2 % 3) % 4" },
+        { "input": ["mod", ["mod", 2, 3], 4], "output": "2 % 3 % 4" },
         { "input": ["mod", 2, ["mod", 3, 4]], "output": "2 % (3 % 4)" },
         { "input": ["mod", ["multiply", 2, 3], 4], "output": "2 * 3 % 4" },
         { "input": ["multiply", ["mod", 2, 3], 4], "output": "2 % 3 * 4" },
-        { "input": ["add", 2, 3, 4], "output": "2 + 3 + 4" },
-        { "input": ["add", ["add", 2, 3], 4], "output": "(2 + 3) + 4" },
+        { "input": ["add", ["add", 2, 3], 4], "output": "2 + 3 + 4" },
         { "input": ["add", 2, ["add", 3, 4]], "output": "2 + (3 + 4)" },
-        { "input": ["subtract", 2, 3, 4], "output": "2 - 3 - 4" },
-        { "input": ["subtract", ["subtract", 2, 3], 4], "output": "(2 - 3) - 4" },
+        { "input": ["subtract", ["subtract", 2, 3], 4], "output": "2 - 3 - 4" },
         { "input": ["subtract", 2, ["subtract", 3, 4]], "output": "2 - (3 - 4)" },
         { "input": ["subtract", ["add", 2, 3], 4], "output": "2 + 3 - 4" },
         { "input": ["subtract", 2, ["add", 3, 4]], "output": "2 - (3 + 4)" },
-        { "input": ["add", ["subtract", 2, 3], 4], "output": "2 - 3 + 4" }
+        { "input": ["add", ["subtract", 2, 3], 4], "output": "2 - 3 + 4" },
+        { "input": ["eq", ["eq", 2, 3], 4], "output": "(2 == 3) == 4" },
+        { "input": ["eq", 2, ["eq", 3, 4]], "output": "2 == (3 == 4)" }
       ]
     },
     {
@@ -86,27 +85,29 @@
         { "input": ["multiply", ["pow", 2, 3], 4], "output": "2 ^ 3 * 4" },
         { "input": ["multiply", 2, ["pow", 3, 4]], "output": "2 * 3 ^ 4" },
         { "input": ["pow", 2, ["multiply", 3, 4]], "output": "2 ^ (3 * 4)" },
+        { "input": ["pow", ["multiply", 2, 3], 4], "output": "(2 * 3) ^ 4" },
         { "input": ["add", ["multiply", 2, 3], 4], "output": "2 * 3 + 4" },
         { "input": ["add", 2, ["multiply", 3, 4]], "output": "2 + 3 * 4" },
         { "input": ["multiply", 2, ["add", 3, 4]], "output": "2 * (3 + 4)" },
+        { "input": ["multiply", ["add", 2, 3], 4], "output": "(2 + 3) * 4" },
         { "input": ["gt", ["add", 2, 3], 4], "output": "2 + 3 > 4" },
+        { "input": ["gt", 2, ["add", 3, 4]], "output": "2 > 3 + 4" },
         { "input": ["add", 2, ["gt", 3, 4]], "output": "2 + (3 > 4)" },
+        { "input": ["add", ["gt", 2, 3], 4], "output": "(2 > 3) + 4" },
         { "input": ["eq", ["gt", 2, 3], 4], "output": "2 > 3 == 4" },
         { "input": ["gt", 2, ["eq", 3, 4]], "output": "2 > (3 == 4)" },
         { "input": ["and", ["eq", 2, 3], 4], "output": "2 == 3 and 4" },
         { "input": ["eq", 2, ["and", 3, 4]], "output": "2 == (3 and 4)" },
+        { "input": ["eq", ["and", 2, 3], 4], "output": "(2 and 3) == 4" },
         { "input": ["or", ["and", 2, 3], 4], "output": "2 and 3 or 4" },
         { "input": ["and", 2, ["or", 3, 4]], "output": "2 and (3 or 4)" },
         { "input": ["and", ["gt", 2, 3], 4], "output": "2 > 3 and 4" },
-        { "input": ["gt", 2, ["and", 3, 4]], "output": "2 > (3 and 4)" }
-      ]
-    },
-    {
-      "category": "operator",
-      "description": "should wrap operators in without vararg support in parenthesis",
-      "tests": [
-        { "input": ["pow", ["pow", 2, 3], 4], "output": "(2 ^ 3) ^ 4" },
-        { "input": ["pow", 2, ["pow", 3, 4]], "output": "2 ^ (3 ^ 4)" }
+        { "input": ["gt", 2, ["and", 3, 4]], "output": "2 > (3 and 4)" },
+        { "input": ["gt", ["and", 2, 3], 4], "output": "(2 and 3) > 4" },
+        { "input": ["pipe", ["and", 2, 3], 4], "output": "2 and 3 | 4" },
+        { "input": ["pipe", 2, ["and", 3, 4]], "output": "2 | 3 and 4" },
+        { "input": ["and", ["pipe", 2, 3], 4], "output": "(2 | 3) and 4" },
+        { "input": ["and", 2, ["pipe", 3, 4]], "output": "2 and (3 | 4)" }
       ]
     },
     {