fix(request): ensure falsy request parameters are passed through

AFFECTS PACKAGES:
@esri/arcgis-rest-request

ISSUES CLOSED: #142

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "editor.tabSize": 2
+}

package.json

@@ -68,7 +68,7 @@
   },
   "lint-staged": {
     "*.ts": [
-      "prettier --write --parser typescript",
+      "prettier --write --parser typescript --tab-width 2 --use-tabs false",
       "tslint",
       "git add"
     ]

packages/arcgis-rest-request/src/utils/process-params.ts

@@ -1,5 +1,5 @@
 /* Copyright (c) 2017 Environmental Systems Research Institute, Inc.
- * Apache-2.0 */
+* Apache-2.0 */
 
 /**
  * Checks parameters to see if we should use FormData to send the request
@@ -47,7 +47,7 @@ export function processParams(params: any): any {
 
   Object.keys(params).forEach(key => {
     const param = params[key];
-    if (!param) {
+    if (!param && param !== 0) {
       return;
     }
     const type = param.constructor.name;
@@ -80,7 +80,7 @@ export function processParams(params: any): any {
         value = param;
         break;
     }
-    if (value) {
+    if (value || value === 0) {
       newParams[key] = value;
     }
   });

packages/arcgis-rest-request/test/utils/process-params.test.ts

@@ -89,13 +89,18 @@ describe("processParams", () => {
     expect(processParams(params)).toEqual(expected);
   });
 
-  it("should exclude null and undefined", () => {
+  it("should exclude null and undefined, but not a zero", () => {
     const params: any = {
       foo: null,
-      bar: undefined
+      bar: undefined,
+      baz: 0
     };
 
-    expect(processParams(params)).toEqual({});
+    const expected = {
+      baz: 0
+    };
+
+    expect(processParams(params)).toEqual(expected);
   });
 
   it("should not require form data for simple requests", () => {