1 files changed, 67 insertions, 0 deletions

diff --git a/spec/javascripts/diffs/components/app_spec.js b/spec/javascripts/diffs/components/app_spec.js
index fdf8bcee756..52f7674a7b3 100644
--- a/spec/javascripts/diffs/components/app_spec.js
+++ b/spec/javascripts/diffs/components/app_spec.js
@@ -34,6 +34,8 @@ describe('diffs/components/app', () => {
       localVue,
       propsData: {
         endpoint: `${TEST_HOST}/diff/endpoint`,
+        endpointMetadata: `${TEST_HOST}/diff/endpointMetadata`,
+        endpointBatch: `${TEST_HOST}/diff/endpointBatch`,
         projectPath: 'namespace/project',
         currentUser: {},
         changesEmptyStateIllustration: '',
@@ -42,6 +44,11 @@ describe('diffs/components/app', () => {
         ...props,
       },
       store,
+      methods: {
+        isLatestVersion() {
+          return true;
+        },
+      },
     });
   }
 
@@ -59,6 +66,58 @@ describe('diffs/components/app', () => {
     wrapper.destroy();
   });
 
+  describe('fetch diff methods', () => {
+    beforeEach(() => {
+      spyOn(window, 'requestIdleCallback').and.callFake(fn => fn());
+      createComponent();
+      spyOn(wrapper.vm, 'fetchDiffFiles').and.callFake(() => Promise.resolve());
+      spyOn(wrapper.vm, 'fetchDiffFilesMeta').and.callFake(() => Promise.resolve());
+      spyOn(wrapper.vm, 'fetchDiffFilesBatch').and.callFake(() => Promise.resolve());
+      spyOn(wrapper.vm, 'setDiscussions');
+      spyOn(wrapper.vm, 'startRenderDiffsQueue');
+    });
+
+    it('calls fetchDiffFiles if diffsBatchLoad is not enabled', () => {
+      wrapper.vm.glFeatures.diffsBatchLoad = false;
+      wrapper.vm.fetchData(false);
+
+      expect(wrapper.vm.fetchDiffFiles).toHaveBeenCalled();
+      wrapper.vm.$nextTick(() => {
+        expect(wrapper.vm.setDiscussions).toHaveBeenCalled();
+        expect(wrapper.vm.startRenderDiffsQueue).toHaveBeenCalled();
+        expect(wrapper.vm.fetchDiffFilesMeta).not.toHaveBeenCalled();
+        expect(wrapper.vm.fetchDiffFilesBatch).not.toHaveBeenCalled();
+      });
+    });
+
+    it('calls fetchDiffFiles if diffsBatchLoad is enabled, and not latest version', () => {
+      wrapper.vm.glFeatures.diffsBatchLoad = true;
+      wrapper.vm.isLatestVersion = () => false;
+      wrapper.vm.fetchData(false);
+
+      expect(wrapper.vm.fetchDiffFiles).toHaveBeenCalled();
+      wrapper.vm.$nextTick(() => {
+        expect(wrapper.vm.setDiscussions).toHaveBeenCalled();
+        expect(wrapper.vm.startRenderDiffsQueue).toHaveBeenCalled();
+        expect(wrapper.vm.fetchDiffFilesMeta).not.toHaveBeenCalled();
+        expect(wrapper.vm.fetchDiffFilesBatch).not.toHaveBeenCalled();
+      });
+    });
+
+    it('calls batch methods if diffsBatchLoad is enabled, and latest version', () => {
+      wrapper.vm.glFeatures.diffsBatchLoad = true;
+      wrapper.vm.fetchData(false);
+
+      expect(wrapper.vm.fetchDiffFiles).not.toHaveBeenCalled();
+      wrapper.vm.$nextTick(() => {
+        expect(wrapper.vm.setDiscussions).toHaveBeenCalled();
+        expect(wrapper.vm.startRenderDiffsQueue).toHaveBeenCalled();
+        expect(wrapper.vm.fetchDiffFilesMeta).toHaveBeenCalled();
+        expect(wrapper.vm.fetchDiffFilesBatch).toHaveBeenCalled();
+      });
+    });
+  });
+
   it('adds container-limiting classes when showFileTree is false with inline diffs', () => {
     createComponent({}, ({ state }) => {
       state.diffs.showTreeList = false;
@@ -93,6 +152,14 @@ describe('diffs/components/app', () => {
     expect(wrapper.contains(GlLoadingIcon)).toBe(true);
   });
 
+  it('displays loading icon on batch loading', () => {
+    createComponent({}, ({ state }) => {
+      state.diffs.isBatchLoading = true;
+    });
+
+    expect(wrapper.contains(GlLoadingIcon)).toBe(true);
+  });
+
   it('displays diffs container when not loading', () => {
     createComponent();