4 files changed, 212 insertions, 0 deletions
diff --git a/spec/frontend/ide/lib/common/disposable_spec.js b/spec/frontend/ide/lib/common/disposable_spec.js
new file mode 100644
index 00000000000..af12ca15369
--- /dev/null
+++ b/spec/frontend/ide/lib/common/disposable_spec.js
@@ -0,0 +1,44 @@
+import Disposable from '~/ide/lib/common/disposable';
+
+describe('Multi-file editor library disposable class', () => {
+  let instance;
+  let disposableClass;
+
+  beforeEach(() => {
+    instance = new Disposable();
+
+    disposableClass = {
+      dispose: jasmine.createSpy('dispose'),
+    };
+  });
+
+  afterEach(() => {
+    instance.dispose();
+  });
+
+  describe('add', () => {
+    it('adds disposable classes', () => {
+      instance.add(disposableClass);
+
+      expect(instance.disposers.size).toBe(1);
+    });
+  });
+
+  describe('dispose', () => {
+    beforeEach(() => {
+      instance.add(disposableClass);
+    });
+
+    it('calls dispose on all cached disposers', () => {
+      instance.dispose();
+
+      expect(disposableClass.dispose).toHaveBeenCalled();
+    });
+
+    it('clears cached disposers', () => {
+      instance.dispose();
+
+      expect(instance.disposers.size).toBe(0);
+    });
+  });
+});
diff --git a/spec/frontend/ide/lib/diff/diff_spec.js b/spec/frontend/ide/lib/diff/diff_spec.js
new file mode 100644
index 00000000000..57f3ac3d365
--- /dev/null
+++ b/spec/frontend/ide/lib/diff/diff_spec.js
@@ -0,0 +1,80 @@
+import { computeDiff } from '~/ide/lib/diff/diff';
+
+describe('Multi-file editor library diff calculator', () => {
+  describe('computeDiff', () => {
+    it('returns empty array if no changes', () => {
+      const diff = computeDiff('123', '123');
+
+      expect(diff).toEqual([]);
+    });
+
+    describe('modified', () => {
+      it('', () => {
+        const diff = computeDiff('123', '1234')[0];
+
+        expect(diff.added).toBeTruthy();
+        expect(diff.modified).toBeTruthy();
+        expect(diff.removed).toBeUndefined();
+      });
+
+      it('', () => {
+        const diff = computeDiff('123\n123\n123', '123\n1234\n123')[0];
+
+        expect(diff.added).toBeTruthy();
+        expect(diff.modified).toBeTruthy();
+        expect(diff.removed).toBeUndefined();
+        expect(diff.lineNumber).toBe(2);
+      });
+    });
+
+    describe('added', () => {
+      it('', () => {
+        const diff = computeDiff('123', '123\n123')[0];
+
+        expect(diff.added).toBeTruthy();
+        expect(diff.modified).toBeUndefined();
+        expect(diff.removed).toBeUndefined();
+      });
+
+      it('', () => {
+        const diff = computeDiff('123\n123\n123', '123\n123\n1234\n123')[0];
+
+        expect(diff.added).toBeTruthy();
+        expect(diff.modified).toBeUndefined();
+        expect(diff.removed).toBeUndefined();
+        expect(diff.lineNumber).toBe(3);
+      });
+    });
+
+    describe('removed', () => {
+      it('', () => {
+        const diff = computeDiff('123', '')[0];
+
+        expect(diff.added).toBeUndefined();
+        expect(diff.modified).toBeUndefined();
+        expect(diff.removed).toBeTruthy();
+      });
+
+      it('', () => {
+        const diff = computeDiff('123\n123\n123', '123\n123')[0];
+
+        expect(diff.added).toBeUndefined();
+        expect(diff.modified).toBeTruthy();
+        expect(diff.removed).toBeTruthy();
+        expect(diff.lineNumber).toBe(2);
+      });
+    });
+
+    it('includes line number of change', () => {
+      const diff = computeDiff('123', '')[0];
+
+      expect(diff.lineNumber).toBe(1);
+    });
+
+    it('includes end line number of change', () => {
+      const diff = computeDiff('123', '')[0];
+
+      expect(diff.endLineNumber).toBe(1);
+    });
+  });
+});
diff --git a/spec/frontend/ide/lib/editor_options_spec.js b/spec/frontend/ide/lib/editor_options_spec.js
new file mode 100644
index 00000000000..d149a883166
--- /dev/null
+++ b/spec/frontend/ide/lib/editor_options_spec.js
@@ -0,0 +1,11 @@
+import editorOptions from '~/ide/lib/editor_options';
+
+describe('Multi-file editor library editor options', () => {
+  it('returns an array', () => {
+    expect(editorOptions).toEqual(jasmine.any(Array));
+  });
+
+  it('contains readOnly option', () => {
+    expect(editorOptions[0].readOnly).toBeDefined();
+  });
+});
diff --git a/spec/frontend/ide/lib/files_spec.js b/spec/frontend/ide/lib/files_spec.js
new file mode 100644
index 00000000000..fe791aa2b74
--- /dev/null
+++ b/spec/frontend/ide/lib/files_spec.js
@@ -0,0 +1,77 @@
+import { viewerInformationForPath } from '~/vue_shared/components/content_viewer/lib/viewer_utils';
+import { decorateFiles, splitParent } from '~/ide/lib/files';
+import { decorateData } from '~/ide/stores/utils';
+
+const TEST_BRANCH_ID = 'lorem-ipsum';
+const TEST_PROJECT_ID = 10;
+
+const createEntries = paths => {
+  const createEntry = (acc, { path, type, children }) => {
+    // Sometimes we need to end the url with a '/'
+    const createUrl = base => (type === 'tree' ? `${base}/` : base);
+
+    const { name, parent } = splitParent(path);
+    const parentEntry = acc[parent];
+
+    acc[path] = {
+      ...decorateData({
+        projectId: TEST_PROJECT_ID,
+        branchId: TEST_BRANCH_ID,
+        id: path,
+        name,
+        path,
+        url: createUrl(`/${TEST_PROJECT_ID}/${type}/${TEST_BRANCH_ID}/-/${path}`),
+        type,
+        previewMode: viewerInformationForPath(path),
+        parentPath: parent,
+        parentTreeUrl: parentEntry
+          ? parentEntry.url
+          : createUrl(`/${TEST_PROJECT_ID}/${type}/${TEST_BRANCH_ID}`),
+      }),
+      tree: children.map(childName => jasmine.objectContaining({ name: childName })),
+    };
+
+    return acc;
+  };
+
+  const entries = paths.reduce(createEntry, {});
+
+  // Wrap entries in jasmine.objectContaining.
+  // We couldn't do this earlier because we still need to select properties from parent entries.
+  return Object.keys(entries).reduce((acc, key) => {
+    acc[key] = jasmine.objectContaining(entries[key]);
+
+    return acc;
+  }, {});
+};
+
+describe('IDE lib decorate files', () => {
+  it('creates entries and treeList', () => {
+    const data = ['app/assets/apples/foo.js', 'app/bugs.js', 'README.md'];
+    const expectedEntries = createEntries([
+      { path: 'app', type: 'tree', children: ['assets', 'bugs.js'] },
+      { path: 'app/assets', type: 'tree', children: ['apples'] },
+      { path: 'app/assets/apples', type: 'tree', children: ['foo.js'] },
+      { path: 'app/assets/apples/foo.js', type: 'blob', children: [] },
+      { path: 'app/bugs.js', type: 'blob', children: [] },
+      { path: 'README.md', type: 'blob', children: [] },
+    ]);
+
+    const { entries, treeList } = decorateFiles({
+      data,
+      branchId: TEST_BRANCH_ID,
+      projectId: TEST_PROJECT_ID,
+    });
+
+    // Here we test the keys and then each key/value individually because `expect(entries).toEqual(expectedEntries)`
+    // was taking a very long time for some reason. Probably due to large objects and nested `jasmine.objectContaining`.
+    const entryKeys = Object.keys(entries);
+
+    expect(entryKeys).toEqual(Object.keys(expectedEntries));
+    entryKeys.forEach(key => {
+      expect(entries[key]).toEqual(expectedEntries[key]);
+    });
+
+    expect(treeList).toEqual([expectedEntries.app, expectedEntries['README.md']]);
+  });
+});