Rewrite and add proper tests

Author: snewcomer

lib/route-recognizer.ts

@@ -688,32 +688,47 @@ class RouteRecognizer<THandler = string> {
   }
 
   generateQueryString(params: Params): string {
-    const pairs: string[] = [];
-    const keys: string[] = Object.keys(params);
-    keys.sort();
-    for (let i = 0; i < keys.length; i++) {
-      const key = keys[i];
-      const value = params[key];
-      if (value == null) {
-        continue;
+    const reducer = (obj: Params, parentPrefix: string | null = null) => (prev: string[], key: string) => {
+      const val = obj[key];
+      if (val === null || val === undefined) {
+        return prev;
       }
-      let pair = encodeURIComponent(key);
-      if (isArray(value)) {
-        for (let j = 0; j < value.length; j++) {
-          const arrayPair = key + "[]" + "=" + encodeURIComponent(value[j]);
-          pairs.push(arrayPair);
-        }
-      } else {
-        pair += "=" + encodeURIComponent(value as string);
-        pairs.push(pair);
+
+      const prefix = parentPrefix ? `${parentPrefix}[${key}]` : key;
+  
+      if (val == null || typeof val === 'function') {
+        prev.push(`${prefix}=`);
+        return prev;
       }
-    }
+  
+      if (isArray(val)) {
+        for (let j = 0; j < val.length; j++) {
+          // handle array query params. array format brackets. (Other options are indices a[0]=b&a[1]=c or repeat a=b&a=c)
+          if (['string', 'number', 'boolean'].includes(typeof val[j])) {
+            const arrayPair = key + "[]" + "=" + encodeURIComponent(val[j]);
+            prev.push(arrayPair);
+          } else {
+            prev.push(Object.keys(val[j] as Params).sort().reduce(reducer(val[j] as Params, prefix + `[${j}]`), []).join('&'));
+          }
+        }
 
-    if (pairs.length === 0) {
-      return "";
+        return prev;
+      } else if (['string', 'number', 'boolean'].includes(typeof val)) {
+        prev.push(`${prefix}=${encodeURIComponent(val as string)}`);
+        return prev;
+      }
+  
+      prev.push(Object.keys(val as Params).sort().reduce(reducer(val as Params, parentPrefix ? prefix : `${prefix}=`), []).join('&'));
+      return prev;
+    };
+  
+    const sortedKeys = Object.keys(params).sort();
+    // avoid appending unnecessary '?'
+    if (!sortedKeys.length || sortedKeys.every((k) => params[k] === undefined || params[k] === null)) {
+      return '';
     }
 
-    return "?" + pairs.join("&");
+    return '?' + sortedKeys.reduce(reducer(params), []).join('&');
   }
 
   parseQueryString(queryString: string): QueryParams {

tests/recognizer-tests.ts

@@ -823,8 +823,7 @@ QUnit.test("Deserialize query param nested object", (assert: Assert) => {
   router.add([{ path: "/foo/bar", handler }]);
 
   const results = router.recognize("/foo/bar?filter=[user][name][$contains]=nick");
-  const p = results && results.queryParams;
-  assert.deepEqual(p, { filter: { user: { name: { $contains: 'scoot' } } } });
+  assert.deepEqual(results!.queryParams, { filter: { user: { name: { $contains: 'nick' } } } });
 });
 
 QUnit.test("Multiple `/` routes recognize", (assert: Assert) => {
@@ -1639,15 +1638,15 @@ QUnit.module("Route Generation", hooks => {
   QUnit.test(
     "Parsing and generation results into the same input string",
     (assert: Assert) => {
-      const query = "filter%20data=date";
+      const query = "filter data=date";
       assert.equal(
         router.generateQueryString(router.parseQueryString(query)),
         "?" + query
       );
     }
   );
 
-  QUnit.only("Generation works with query params", (assert: Assert) => {
+  QUnit.test("Generation works with query params", (assert: Assert) => {
     assert.equal(
       router.generate("index", { queryParams: { filter: "date" } }),
       "/?filter=date"
@@ -1732,8 +1731,16 @@ QUnit.module("Route Generation", hooks => {
       "/?filter=date&sort=0"
     );
     assert.equal(
-      router.generate("index", { queryParams: { filter: { user: { name: { $contains: 'scoot' } } }, sort: 0 } }),
-      "/?filter=[user][name][$contains]=scoot"
+      router.generate("index", { queryParams: { filter: { age: 10, user: { name: { $contains: 'scoot' } } }, sort: 0 } }),
+      "/?filter=[age]=10&filter=[user][name][$contains]=scoot&sort=0"
+    );
+    assert.equal(
+      router.generate("index", { queryParams: { sort: 0, filter: { age: 0, user: { name: { $contains: 'scoot' } } } } }),
+      "/?filter=[age]=0&filter=[user][name][$contains]=scoot&sort=0"
+    );
+    assert.equal(
+      router.generate("index", { queryParams: { sort: 0, filter: { name: 'bike', children: [{ name: { $contains: 'scoot' } }] } }, sort: 0 }),
+      "/?filter=[children][0][name][$contains]=scoot&filter=[name]=bike&sort=0"
     );
   });