Support array of arrays

packages/arcgis-rest-request/src/utils/encode-query-string.ts

@@ -3,7 +3,19 @@
 
 import { processParams } from "./process-params";
 
-export function encodeParam(key: string, value: any) {
+/**
+ * Encodes keys and parameters for use in a URL's query string.
+ *
+ * @param key Parameter's key
+ * @param value Parameter's value
+ * @returns Query string with key and value pairs separated by "&"
+ */
+export function encodeParam(key: string, value: any): string {
+  // For array of arrays, repeat key=value for each element of containing array
+  if (Array.isArray(value) && value[0] && Array.isArray(value[0])) {
+    return value.map((arrayElem: string) => encodeParam(key, arrayElem)).join("&");
+  }
+
   return encodeURIComponent(key) + "=" + encodeURIComponent(value);
 }
 

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

@@ -75,14 +75,13 @@ export function processParams(params: any): any {
     // null, undefined, function are excluded. If you want to send an empty key you need to send an empty string "".
     switch (type) {
       case "Array":
-        // Based on the first element of the array, classify array as an array of objects to be stringified
-        // or an array of non-objects to be comma-separated
+        // Based on the first element of the array, classify array as an array of arrays, an array of objects
+        // to be stringified, or an array of non-objects to be comma-separated
+        const firstElementType = param[0]?.constructor?.name;
         value =
-          param[0] &&
-          param[0].constructor &&
-          param[0].constructor.name === "Object"
-            ? JSON.stringify(param)
-            : param.join(",");
+          firstElementType === "Array" ? param : // pass thru array of arrays
+          firstElementType === "Object" ? JSON.stringify(param) : // stringify array of objects
+          param.join(","); // join other types of array elements
         break;
       case "Object":
         value = JSON.stringify(param);
@@ -100,7 +99,7 @@ export function processParams(params: any): any {
         value = param;
         break;
     }
-    if (value || value === 0 || typeof value === "string") {
+    if (value || value === 0 || typeof value === "string" || Array.isArray(value)) {
       newParams[key] = value;
     }
   });

packages/arcgis-rest-request/test/utils/encode-query-string.test.ts

@@ -0,0 +1,18 @@
+/* Copyright (c) 2018 Environmental Systems Research Institute, Inc.
+ * Apache-2.0 */
+
+import { encodeParam } from "../../src/utils/encode-query-string";
+
+describe("encodeQueryString", () => {
+  it("should encode simple value", () => {
+    expect(encodeParam("key", "value")).toEqual("key=value");
+  });
+
+  it("should encode array", () => {
+    expect(encodeParam("key", ["value1", "value2"])).toEqual("key=value1%2Cvalue2");
+  });
+
+  it("should encode array of arrays", () => {
+    expect(encodeParam("key", [["value1a", "value1b"], ["value2"]])).toEqual("key=value1a%2Cvalue1b&key=value2");
+  });
+});

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

@@ -68,7 +68,7 @@ describe("processParams", () => {
     expect(processParams(params)).toEqual(expected);
   });
 
-  it("should comma seperate arrays of non objects", () => {
+  it("should comma separate arrays of non objects", () => {
     const params = {
       foo: ["bar", "baz"]
     };
@@ -80,6 +80,18 @@ describe("processParams", () => {
     expect(processParams(params)).toEqual(expected);
   });
 
+  it("should pass array of arrays through", () => {
+    const params = {
+      foo: [["bar1"], ["baz1", "baz2"]]
+    };
+
+    const expected = {
+      foo: [["bar1"], ["baz1", "baz2"]]
+    };
+
+    expect(processParams(params)).toEqual(expected);
+  });
+
   it("should stringify booleans", () => {
     const params = {
       foo: true,