From 7df16a1c42629f90b843b9fb45b9fc0be8503f3e Mon Sep 17 00:00:00 2001
From: Artur Pata <artur.pata@gmail.com>
Date: Thu, 9 Jan 2025 15:01:09 +0200
Subject: [PATCH] Handle empty search string and badly formed search strings

---
 .../dashboard/util/url-search-params.test.ts  | 24 +++++++++++++++++++
 assets/js/dashboard/util/url-search-params.ts | 23 ++++++++++++++----
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/assets/js/dashboard/util/url-search-params.test.ts b/assets/js/dashboard/util/url-search-params.test.ts
index c1a9ceef0a662..980e6f1ef02c0 100644
--- a/assets/js/dashboard/util/url-search-params.test.ts
+++ b/assets/js/dashboard/util/url-search-params.test.ts
@@ -136,8 +136,32 @@ describe(`${serializeSimpleSearchEntry.name} and ${parseSimpleSearchEntry.name}`
   )
 })
 
+describe(`${parseSearch.name}`, () => {
+  it.each([
+    ['?', {}, ''],
+    ['?=&&', {}, ''],
+    ['?=undefined', {}, ''],
+    ['?foo=', { foo: '' }, '?foo='],
+    ['??foo', { '?foo': '' }, '?%3Ffoo='],
+    [
+      '?f=is,visit:page,/any/page&f',
+      { filters: [['is', 'visit:page', ['/any/page']]] },
+      '?f=is,visit:page,/any/page'
+    ]
+  ])(
+    'for search string %s, returns search record %p, which in turn stringifies to %s',
+    (searchString, expectedSearchRecord, expectedRestringifiedResult) => {
+      expect(parseSearch(searchString)).toEqual(expectedSearchRecord)
+      expect(stringifySearch(expectedSearchRecord)).toEqual(
+        expectedRestringifiedResult
+      )
+    }
+  )
+})
+
 describe(`${stringifySearch.name}`, () => {
   it.each([
+    [{}, ''],
     [
       {
         filters: [['is', 'props:browser_language', ['en-US']]]
diff --git a/assets/js/dashboard/util/url-search-params.ts b/assets/js/dashboard/util/url-search-params.ts
index 1492ce94e562b..485cd1cf8563b 100644
--- a/assets/js/dashboard/util/url-search-params.ts
+++ b/assets/js/dashboard/util/url-search-params.ts
@@ -31,15 +31,27 @@ export function stringifySearch(
   return `?${serializedFilters.concat(serializedLabels).concat(definedSearchEntries).join('&')}`
 }
 
+export function normalizeSearchString(searchString: string): string {
+  return searchString.startsWith('?') ? searchString.slice(1) : searchString
+}
+
 export function parseSearch(searchString: string): Record<string, unknown> {
   const searchRecord: Record<string, string | boolean> = {}
   const filters: Filter[] = []
   const labels: FilterClauseLabels = {}
 
-  for (const param of searchString.startsWith('?')
-    ? searchString.slice(1).split('&')
-    : searchString.split('&')) {
-    const [key, rawValue] = param.split('=')
+  const normalizedSearchString = normalizeSearchString(searchString)
+
+  if (!normalizedSearchString.length) {
+    return searchRecord
+  }
+
+  const meaningfulParams = normalizedSearchString
+    .split('&')
+    .filter((i) => i.length > 0)
+
+  for (const param of meaningfulParams) {
+    const [key, rawValue = ''] = param.split('=')
     switch (key) {
       case FILTER_URL_PARAM_NAME: {
         const filter = parseFilter(rawValue)
@@ -55,6 +67,9 @@ export function parseSearch(searchString: string): Record<string, unknown> {
         }
         break
       }
+      case '': {
+        break
+      }
       default: {
         const parsedValue = parseSimpleSearchEntry(rawValue)
         if (parsedValue !== null) {