1 files changed, 90 insertions, 0 deletions
diff --git a/spec/javascripts/pager_spec.js b/spec/javascripts/pager_spec.js
new file mode 100644
index 00000000000..1d3e1263371
--- /dev/null
+++ b/spec/javascripts/pager_spec.js
@@ -0,0 +1,90 @@
+/* global fixture */
+
+import '~/pager';
+
+describe('pager', () => {
+  const Pager = window.Pager;
+
+  it('is defined on window', () => {
+    expect(window.Pager).toBeDefined();
+  });
+
+  describe('init', () => {
+    const originalHref = window.location.href;
+
+    beforeEach(() => {
+      setFixtures('<div class="content_list"></div><div class="loading"></div>');
+      spyOn($, 'ajax');
+    });
+
+    afterEach(() => {
+      window.history.replaceState({}, null, originalHref);
+    });
+
+    it('should use data-href attribute from list element', () => {
+      const href = `${gl.TEST_HOST}/some_list.json`;
+      setFixtures(`<div class="content_list" data-href="${href}"></div>`);
+      Pager.init();
+      expect(Pager.url).toBe(href);
+    });
+
+    it('should use current url if data-href attribute not provided', () => {
+      const href = `${gl.TEST_HOST}/some_list`;
+      spyOn(gl.utils, 'removeParams').and.returnValue(href);
+      Pager.init();
+      expect(Pager.url).toBe(href);
+    });
+
+    it('should get initial offset from query parameter', () => {
+      window.history.replaceState({}, null, '?offset=100');
+      Pager.init();
+      expect(Pager.offset).toBe(100);
+    });
+
+    it('keeps extra query parameters from url', () => {
+      window.history.replaceState({}, null, '?filter=test&offset=100');
+      const href = `${gl.TEST_HOST}/some_list?filter=test`;
+      spyOn(gl.utils, 'removeParams').and.returnValue(href);
+      Pager.init();
+      expect(gl.utils.removeParams).toHaveBeenCalledWith(['limit', 'offset']);
+      expect(Pager.url).toEqual(href);
+    });
+  });
+
+  describe('getOld', () => {
+    beforeEach(() => {
+      setFixtures('<div class="content_list" data-href="/some_list"></div><div class="loading"></div>');
+      Pager.init();
+    });
+
+    it('shows loader while loading next page', () => {
+      spyOn(Pager.loading, 'show');
+      Pager.getOld();
+      expect(Pager.loading.show).toHaveBeenCalled();
+    });
+
+    it('hides loader on success', () => {
+      spyOn($, 'ajax').and.callFake(options => options.success({}));
+      spyOn(Pager.loading, 'hide');
+      Pager.getOld();
+      expect(Pager.loading.hide).toHaveBeenCalled();
+    });
+
+    it('hides loader on error', () => {
+      spyOn($, 'ajax').and.callFake(options => options.error());
+      spyOn(Pager.loading, 'hide');
+      Pager.getOld();
+      expect(Pager.loading.hide).toHaveBeenCalled();
+    });
+
+    it('sends request to url with offset and limit params', () => {
+      spyOn($, 'ajax');
+      Pager.offset = 100;
+      Pager.limit = 20;
+      Pager.getOld();
+      const [{ data, url }] = $.ajax.calls.argsFor(0);
+      expect(data).toBe('limit=20&offset=100');
+      expect(url).toBe('/some_list');
+    });
+  });
+});