fix: query string array support (#182)

* fix: query string array support

* fix: remove elvis operator

* fix: use the objectToQueryString function at tepper runner

* chore: bump version to 0.4.2

* fix: skip undefined values

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tepper",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "description": "Modern library for testing HTTP servers",
   "main": "dist/tepper.js",
   "engines": {
@@ -73,4 +73,4 @@
     "node-fetch": "^2.6.1",
     "@types/node-fetch": "2.6.2"
   }
-}
+}

src/TepperConfig.ts

@@ -1,12 +1,11 @@
-import { ParsedUrlQueryInput } from "querystring"
 import { DebugOptions } from "./DebugOptions"
 
 export type TepperConfig = {
   readonly method: "GET" | "POST" | "PUT" | "PATCH" | "DELETE"
   readonly path: string
   readonly body: string | object | null
   readonly isForm: boolean
-  readonly query: ParsedUrlQueryInput | null
+  readonly query: object | null
   readonly redirects: number
   readonly expectedStatus: number | null
   readonly expectedBody:

src/TepperRunner.ts

@@ -4,6 +4,7 @@ import fetch from "node-fetch"
 import qs from "querystring"
 import { Readable } from "stream"
 import { FormDataEncoder } from "form-data-encoder"
+import { URLSearchParams } from "url"
 import { listenAppPromised, listenServerPromised } from "./utils/listenPromised"
 import { getBaseUrl } from "./utils/getBaseUrl"
 import { closePromised } from "./utils/closePromised"
@@ -12,6 +13,7 @@ import { TepperConfig } from "./TepperConfig"
 import { TepperResult } from "./TepperResult"
 import { BaseUrlServerOrExpress } from "./BaseUrlServerOrExpress"
 import { objectToFormData } from "./forms/objectToFormData"
+import { objectToQueryString } from "./queries/objectToQueryString"
 
 function isExpressApp(
   baseUrlServerOrExpress: BaseUrlServerOrExpress,
@@ -63,9 +65,7 @@ export class TepperRunner {
     endpoint: string,
     config: TepperConfig,
   ): Promise<TepperResult> {
-    const endpointWithQuery = config.query
-      ? endpoint.concat("?").concat(qs.stringify(config.query))
-      : endpoint
+    const endpointWithQuery = this.appendQuery(endpoint, config)
 
     const { body, headers } = this.insertBodyIfPresent(config)
 
@@ -112,6 +112,16 @@ export class TepperRunner {
     return result
   }
 
+  private static appendQuery(endpoint: string, config: TepperConfig) {
+    if (!config.query) {
+      return endpoint
+    }
+
+    return endpoint
+      .concat("?")
+      .concat(objectToQueryString(config.query).toString())
+  }
+
   private static insertBodyIfPresent(config: TepperConfig): {
     body: any
     headers: object

src/queries/objectToQueryString.spec.ts

@@ -0,0 +1,31 @@
+import { objectToQueryString } from "./objectToQueryString"
+
+describe("objectToQueryString", () => {
+  it("serializes a query with strings", () => {
+    const query = {
+      hello: "world",
+    }
+
+    const result = objectToQueryString(query)
+
+    expect(result).toEqual("hello=world")
+  })
+
+  it("serializes a query with an array", () => {
+    const query = {
+      tags: ["first-tag", "second-tag"],
+    }
+
+    const result = objectToQueryString(query)
+
+    expect(result).toEqual("tags[]=first-tag&tags[]=second-tag")
+  })
+
+  it("skips undefined values", () => {
+    const query = { empty: undefined }
+
+    const result = objectToQueryString(query)
+
+    expect(result).toEqual("")
+  })
+})

src/queries/objectToQueryString.ts

@@ -0,0 +1,18 @@
+import { URLSearchParams } from "url"
+
+export function objectToQueryString(query: object) {
+  const params = new URLSearchParams()
+  const arrayIndicator = "__array_indicator__"
+
+  for (const [key, value] of Object.entries(query)) {
+    if (Array.isArray(value)) {
+      for (const v of value) {
+        params.append(key + arrayIndicator, v)
+      }
+    } else if (value != null) {
+      params.append(key, (value && value.toString()) || "")
+    }
+  }
+
+  return params.toString().replace(new RegExp(arrayIndicator, "g"), "[]")
+}

test/query-params.spec.ts

@@ -14,4 +14,45 @@ describe("query params", () => {
 
     expect(body).toEqual({ hello: "world" })
   })
+
+  it("skips undefined values", async () => {
+    const app = express().get("/", (req, res) => {
+      res.send(req.query)
+    })
+
+    const { body } = await tepper(app)
+      .get("")
+      .withQuery({ hello: undefined })
+      .run()
+
+    expect(body).toEqual({})
+  })
+
+  describe("array params", () => {
+    it("parses correctly an array", async () => {
+      const app = express().get("/", (req, res) => {
+        res.send(req.query)
+      })
+
+      const { body } = await tepper(app)
+        .get("")
+        .withQuery({ tags: ["first-tag", "second-tag"] })
+        .run()
+
+      expect(body).toEqual({ tags: ["first-tag", "second-tag"] })
+    })
+
+    it("parses correctly an array with one element", async () => {
+      const app = express().get("/", (req, res) => {
+        res.send(req.query)
+      })
+
+      const { body } = await tepper(app)
+        .get("")
+        .withQuery({ tags: ["first-tag"] })
+        .run()
+
+      expect(body).toEqual({ tags: ["first-tag"] })
+    })
+  })
 })