From b95257371d0ebb166d3a147a771ad9aecba0fbb8 Mon Sep 17 00:00:00 2001
From: Eduardo San Martin Morote <posva13@gmail.com>
Date: Thu, 6 Aug 2020 10:03:44 +0200
Subject: [PATCH] fix(query): remove undefined values

Close #3276
---
 src/util/query.js             | 68 +++++++++++++++++++----------------
 test/unit/specs/query.spec.js | 11 ++++++
 2 files changed, 49 insertions(+), 30 deletions(-)

diff --git a/src/util/query.js b/src/util/query.js
index b2c5286a5..c017f2b5d 100644
--- a/src/util/query.js
+++ b/src/util/query.js
@@ -9,9 +9,10 @@ const commaRE = /%2C/g
 // fixed encodeURIComponent which is more conformant to RFC3986:
 // - escapes [!'()*]
 // - preserve commas
-const encode = str => encodeURIComponent(str)
-  .replace(encodeReserveRE, encodeReserveReplacer)
-  .replace(commaRE, ',')
+const encode = str =>
+  encodeURIComponent(str)
+    .replace(encodeReserveRE, encodeReserveReplacer)
+    .replace(commaRE, ',')
 
 const decode = decodeURIComponent
 
@@ -30,11 +31,15 @@ export function resolveQuery (
   }
   for (const key in extraQuery) {
     const value = extraQuery[key]
-    parsedQuery[key] = Array.isArray(value) ? value.map(v => '' + v) : '' + value
+    parsedQuery[key] = Array.isArray(value)
+      ? value.map(castQueryParamValue)
+      : castQueryParamValue(value)
   }
   return parsedQuery
 }
 
+const castQueryParamValue = value => (value == null ? value : '' + value)
+
 function parseQuery (query: string): Dictionary<string> {
   const res = {}
 
@@ -47,9 +52,7 @@ function parseQuery (query: string): Dictionary<string> {
   query.split('&').forEach(param => {
     const parts = param.replace(/\+/g, ' ').split('=')
     const key = decode(parts.shift())
-    const val = parts.length > 0
-      ? decode(parts.join('='))
-      : null
+    const val = parts.length > 0 ? decode(parts.join('=')) : null
 
     if (res[key] === undefined) {
       res[key] = val
@@ -64,33 +67,38 @@ function parseQuery (query: string): Dictionary<string> {
 }
 
 export function stringifyQuery (obj: Dictionary<string>): string {
-  const res = obj ? Object.keys(obj).map(key => {
-    const val = obj[key]
-
-    if (val === undefined) {
-      return ''
-    }
+  const res = obj
+    ? Object.keys(obj)
+      .map(key => {
+        const val = obj[key]
 
-    if (val === null) {
-      return encode(key)
-    }
+        if (val === undefined) {
+          return ''
+        }
 
-    if (Array.isArray(val)) {
-      const result = []
-      val.forEach(val2 => {
-        if (val2 === undefined) {
-          return
+        if (val === null) {
+          return encode(key)
         }
-        if (val2 === null) {
-          result.push(encode(key))
-        } else {
-          result.push(encode(key) + '=' + encode(val2))
+
+        if (Array.isArray(val)) {
+          const result = []
+          val.forEach(val2 => {
+            if (val2 === undefined) {
+              return
+            }
+            if (val2 === null) {
+              result.push(encode(key))
+            } else {
+              result.push(encode(key) + '=' + encode(val2))
+            }
+          })
+          return result.join('&')
         }
-      })
-      return result.join('&')
-    }
 
-    return encode(key) + '=' + encode(val)
-  }).filter(x => x.length > 0).join('&') : null
+        return encode(key) + '=' + encode(val)
+      })
+      .filter(x => x.length > 0)
+      .join('&')
+    : null
   return res ? `?${res}` : ''
 }
diff --git a/test/unit/specs/query.spec.js b/test/unit/specs/query.spec.js
index 58060ff2c..9c73debe4 100644
--- a/test/unit/specs/query.spec.js
+++ b/test/unit/specs/query.spec.js
@@ -20,10 +20,21 @@ describe('Query utils', () => {
       })
     })
 
+    it('should keep undefined and null query values', () => {
+      const query = resolveQuery('', { a: undefined, b: null })
+      expect(query).toEqual({ a: undefined, b: null })
+    })
+
+    it('should keep null query values in arrays', () => {
+      const query = resolveQuery('', { baz: [null, '2'] })
+      expect(query).toEqual({ baz: [null, '2'] })
+    })
+
     it('should cast query values into string', () => {
       const query = resolveQuery('foo=bar&foo=k', { baz: 1 })
       expect(query.baz).toBe('1')
     })
+
     it('should cast query array values into string', () => {
       const query = resolveQuery('foo=bar&foo=k', { baz: [1, '2'] })
       expect(query.baz).toEqual(['1', '2'])