From 61598bc5457150be912c5cbd988e519965b60fa0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20K=C4=99drzy=C5=84ski?= <kedrzu@gmail.com>
Date: Fri, 25 Aug 2023 15:44:47 +0200
Subject: [PATCH] feat(utils): added util to parse query

---
 packages/utils/src/index.ts                   |  5 +-
 packages/utils/src/url/parseQuery.ts          | 56 +++++++++++++++++++
 packages/utils/src/url/queryTypes.ts          |  4 ++
 .../utils/src/{ => url}/stringifyQuery.ts     |  4 +-
 4 files changed, 65 insertions(+), 4 deletions(-)
 create mode 100644 packages/utils/src/url/parseQuery.ts
 create mode 100644 packages/utils/src/url/queryTypes.ts
 rename packages/utils/src/{ => url}/stringifyQuery.ts (81%)

diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index 4524566..be17fc4 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -14,6 +14,10 @@ export * from './array/forEachParalell.js';
 export * from './string/formatWith.js';
 export * from './string/isDigit.js';
 
+export * from './url/stringifyQuery.js';
+export * from './url/parseQuery.js';
+export * from './url/queryTypes.js';
+
 export * from './assert.js';
 export * from './cachedGetter.js';
 export * from './cachedProp.js';
@@ -40,4 +44,3 @@ export * from './timeout.js';
 export * from './writable.js';
 export * from './promiseAll.js';
 export * from './getTopLevelDomain.js';
-export * from './stringifyQuery.js';
diff --git a/packages/utils/src/url/parseQuery.ts b/packages/utils/src/url/parseQuery.ts
new file mode 100644
index 0000000..14bc47a
--- /dev/null
+++ b/packages/utils/src/url/parseQuery.ts
@@ -0,0 +1,56 @@
+import { QueryParams, QueryParamsSimple } from './queryTypes.js';
+
+export function parseQuery(querystring: string | null | undefined): QueryParamsSimple;
+export function parseQuery(
+    querystring: string | null | undefined,
+    options: { multiple: false },
+): QueryParamsSimple;
+export function parseQuery(
+    querystring: string | null | undefined,
+    options: { multiple: true },
+): QueryParams;
+export function parseQuery(
+    querystring: string | null | undefined,
+    options?: { multiple: boolean },
+): QueryParams {
+    const query: QueryParams = {};
+    const multiple = options?.multiple || false;
+
+    if (!querystring) {
+        return query;
+    }
+
+    if (querystring.startsWith('?')) {
+        querystring = querystring.slice(1);
+    }
+
+    for (const item of querystring.split('&')) {
+        const [rawKey, rawValue] = item.split('=');
+        const key = decodeURIComponent(rawKey);
+        const value = decodeURIComponent(rawValue);
+
+        // Sometimes a query string can have multiple values
+        // for the same key, so to factor that case in, you
+        // could collect an array of values for the same key
+        let entry = query[key];
+
+        if (entry === undefined) {
+            query[key] = value;
+            continue;
+        }
+
+        if (!multiple) {
+            // Allows only for a single value per key
+            continue;
+        }
+
+        // If the value for this key was not previously an array, update it
+        if (!Array.isArray(entry)) {
+            query[key] = entry = [entry];
+        }
+
+        entry.push(value);
+    }
+
+    return query;
+}
diff --git a/packages/utils/src/url/queryTypes.ts b/packages/utils/src/url/queryTypes.ts
new file mode 100644
index 0000000..c51456b
--- /dev/null
+++ b/packages/utils/src/url/queryTypes.ts
@@ -0,0 +1,4 @@
+type QueryParamValue = string | null;
+export type QueryParam = QueryParamValue | QueryParamValue[];
+export type QueryParams = Record<string, QueryParam | undefined>;
+export type QueryParamsSimple = Record<string, string | undefined | null>;
diff --git a/packages/utils/src/stringifyQuery.ts b/packages/utils/src/url/stringifyQuery.ts
similarity index 81%
rename from packages/utils/src/stringifyQuery.ts
rename to packages/utils/src/url/stringifyQuery.ts
index 7804130..b874a5c 100644
--- a/packages/utils/src/stringifyQuery.ts
+++ b/packages/utils/src/url/stringifyQuery.ts
@@ -1,6 +1,4 @@
-type QueryParamValue = string | null;
-export type QueryParam = QueryParamValue | QueryParamValue[];
-export type QueryParams = Record<string, QueryParam | undefined>;
+import { QueryParams } from './queryTypes.js';
 
 export function stringifyQuery(params: QueryParams) {
     let qs = '';