Omit query params with `undefined` values from API calls

The previous version stated that it aimed to match the behavior of the
`query-string` package but it was actually tested against Node's
`querystring` package, which has slightly different behavior for this
edge case. It omits parameters with `undefined` values and renders empty
parameters for `null` values.

The notebook view was calling `api.search({ uri: undefined, ... })` and
this translated to `/api/search?uri=&...` which caused an error.

Omit parameters instead in this case.

src/sidebar/services/api.js

@@ -128,15 +128,18 @@ function createAPICall(
           params
         );
 
-        /** @param {Param?} param */
-        const serialize = param => param?.toString() ?? '';
-
         const apiURL = new URL(url);
         for (let [key, value] of Object.entries(queryParams)) {
-          if (Array.isArray(value)) {
-            value.forEach(v => apiURL.searchParams.append(key, serialize(v)));
-          } else {
-            apiURL.searchParams.append(key, serialize(value));
+          if (!Array.isArray(value)) {
+            value = [value];
+          }
+          for (let item of value) {
+            // eslint-disable-next-line eqeqeq
+            if (item == null) {
+              // Skip all parameters with nullish values.
+              continue;
+            }
+            apiURL.searchParams.append(key, item.toString());
           }
         }
 

src/sidebar/services/test/api-test.js

@@ -176,7 +176,7 @@ describe('APIService', () => {
   // Test serialization of nullish parameters in API calls. This behavior matches
   // the query-string package that we used to use.
   it('sends empty query parameters if value is nullish', () => {
-    expectCall('get', 'search?a=&b=&c=false&d=');
+    expectCall('get', 'search?c=false');
 
     return api.search({ a: undefined, b: null, c: false, d: [null] });
   });

src/sidebar/util/url.js

@@ -7,19 +7,20 @@
  *   replaceURLParams('/things/:id', {id: 'foo', q: 'bar'}) =>
  *     {url: '/things/foo', unusedParams: {q: 'bar'}}
  *
+ * @template Param
  * @param {string} url
- * @param {Record<string, string>} params
- * @return {{ url: string, unusedParams: Record<string, string>}}
+ * @param {Record<string, Param>} params
+ * @return {{ url: string, unusedParams: Record<string, Param>}}
  */
 export function replaceURLParams(url, params) {
-  /** @type {Record<string, string>} */
+  /** @type {Record<string, Param>} */
   const unusedParams = {};
   for (const param in params) {
     if (params.hasOwnProperty(param)) {
       const value = params[param];
       const urlParam = ':' + param;
       if (url.indexOf(urlParam) !== -1) {
-        url = url.replace(urlParam, encodeURIComponent(value));
+        url = url.replace(urlParam, encodeURIComponent(String(value)));
       } else {
         unusedParams[param] = value;
       }