test(http): Add tests for NsHttpBackEnd

Author: vakrilov

nativescript-angular/http-client/http-client.module.ts

@@ -9,6 +9,8 @@ global.__extends = cachedExtends;
 import { NSFileSystem } from "../file-system/ns-file-system";
 import { NsHttpBackEnd } from "./ns-http-backend";
 
+export { NsHttpBackEnd } from "./ns-http-backend";
+
 @NgModule({
     providers: [
         NSFileSystem,

tests/app/tests/http-client-ns-backend.ts

@@ -0,0 +1,80 @@
+// make sure you import mocha-config before @angular/core
+import { assert } from "./test-config";
+import { NSFileSystem } from "nativescript-angular/file-system/ns-file-system";
+import { NsHttpBackEnd } from "nativescript-angular/http-client";
+
+import { XhrFactory, HttpRequest, HttpResponse, HttpErrorResponse } from "@angular/common/http";
+import { File } from "tns-core-modules/file-system";
+
+class NSFileSystemMock implements NSFileSystem {
+    public currentApp(): any {
+        return { path: "/app/dir" };
+    }
+
+    public fileFromPath(path: string): any {
+        if (path === "/app/dir/data.json") {
+            return {
+                readText: () => { return Promise.resolve(` { "result": "success" } `); }
+            };
+        }
+        throw new Error("Opening non-existing file");
+    }
+
+    public fileExists(path: string): boolean {
+        return path === "/app/dir/data.json";
+    }
+}
+class XhrFactoryMock implements XhrFactory {
+    build(): XMLHttpRequest {
+        throw new Error("Hi, from XhrFactoryMock!");
+    }
+}
+
+describe("NsHttpBackEnd ", () => {
+    let backend: NsHttpBackEnd;
+
+    before(() => {
+        backend = new NsHttpBackEnd(new XhrFactoryMock(), new NSFileSystemMock());
+    });
+
+    it("should work with local files prefixed with '~'", (done) => {
+        const req = new HttpRequest("GET", "~/data.json");
+        let nextCalled = false;
+        backend.handle(req).subscribe(
+            (response: HttpResponse<{ result: string }>) => {
+                assert.equal(response.body.result, "success");
+                nextCalled = true;
+            }, (error) => {
+                done(error);
+            }, () => {
+                assert.isTrue(nextCalled, "next callback should be called with result.");
+                done();
+            });
+    });
+
+    it("should return 404 for non-existing local files prefixed with '~'", (done) => {
+        const req = new HttpRequest("GET", "~/non/existing/file.json");
+        backend.handle(req).subscribe(
+            (response) => {
+                assert.fail("next callback should not be called for non existing file.");
+            }, (error: HttpErrorResponse) => {
+                assert.equal(error.status, 404);
+                done();
+            }, () => {
+                assert.fail("next callback should not be called for non existing file.");
+            });
+    });
+
+    it("should fallback to XHR backend when requesting remote files", (done) => {
+        const req = new HttpRequest("GET", "https://nativescript.org/");
+        backend.handle(req).subscribe(
+            (response) => {
+                assert.fail("next callback should not be called for non existing file.");
+            }, (error: Error) => {
+                assert.equal(error.message, "Hi, from XhrFactoryMock!");
+                done();
+            }, () => {
+                assert.fail("next callback should not be called for non existing file.");
+            });
+    });
+});