From 1ff21fc038be373d0a2078a2763c5c0f0acd14dd Mon Sep 17 00:00:00 2001
From: Tanishq Gandhi <tangandhi19@gmail.com>
Date: Thu, 9 Jul 2026 22:44:36 -0700
Subject: [PATCH 1/4] fix(dashboard): sort datasets by creation time (newest
 first)

---
 .../sort-button/sort-button.component.html    | 32 +++++++------
 .../sort-button/sort-button.component.spec.ts | 13 ++++++
 .../user/sort-button/sort-button.component.ts | 10 +++-
 .../user-dataset/user-dataset.component.html  | 46 +++++++++++--------
 .../user-dataset.component.spec.ts            |  7 +++
 .../user-dataset/user-dataset.component.ts    |  9 +++-
 .../hub-search-result.component.html          |  5 +-
 .../hub-search-result.component.ts            |  3 ++
 8 files changed, 87 insertions(+), 38 deletions(-)

diff --git a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html
index d3a2aadd934..9d69fc93041 100644
--- a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html
+++ b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html
@@ -34,13 +34,15 @@
 
 <nz-dropdown-menu #sortOptions="nzDropdownMenu">
   <ul nz-menu>
-    <li nz-menu-item>
-      <button
-        (click)="lastSort()"
-        nz-button>
-        By Edit Time
-      </button>
-    </li>
+    @if (showEditTime) {
+      <li nz-menu-item>
+        <button
+          (click)="lastSort()"
+          nz-button>
+          By Edit Time
+        </button>
+      </li>
+    }
     <li nz-menu-item>
       <button
         (click)="dateSort()"
@@ -48,13 +50,15 @@
         By Create Time
       </button>
     </li>
-    <li nz-menu-item>
-      <button
-        (click)="execSort()"
-        nz-button>
-        By Execution Time
-      </button>
-    </li>
+    @if (showExecutionTime) {
+      <li nz-menu-item>
+        <button
+          (click)="execSort()"
+          nz-button>
+          By Execution Time
+        </button>
+      </li>
+    }
     <li nz-menu-item>
       <button
         (click)="ascSort()"
diff --git a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
index 516309e2a0f..1f5eeef3ca2 100644
--- a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
+++ b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
@@ -76,4 +76,17 @@ describe("SortButtonComponent", () => {
     expect(component.sortMethod).toBe(SortMethod.ExecutionTimeDesc);
     expect(emitSpy).toHaveBeenCalledWith(SortMethod.ExecutionTimeDesc);
   });
+
+  it("shows the edit-time and execution-time options by default (e.g. for workflows)", () => {
+    expect(component.showEditTime).toBe(true);
+    expect(component.showExecutionTime).toBe(true);
+  });
+
+  it("can hide edit-time and execution-time options (e.g. for datasets, which have neither)", () => {
+    component.showEditTime = false;
+    component.showExecutionTime = false;
+    fixture.detectChanges();
+    expect(component.showEditTime).toBe(false);
+    expect(component.showExecutionTime).toBe(false);
+  });
 });
diff --git a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.ts b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.ts
index 3282784d075..6ab39b7197f 100644
--- a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.ts
+++ b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.ts
@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import { Component, EventEmitter, Output } from "@angular/core";
+import { Component, EventEmitter, Input, Output } from "@angular/core";
 import { SortMethod } from "../../../type/sort-method";
 import { NzDropdownADirective, NzDropdownDirective, NzDropdownMenuComponent } from "ng-zorro-antd/dropdown";
 import { NzSpaceCompactItemDirective } from "ng-zorro-antd/space";
@@ -47,6 +47,14 @@ import { NzMenuDirective, NzMenuItemComponent } from "ng-zorro-antd/menu";
 export class SortButtonComponent {
   @Output()
   public sortMethodChange = new EventEmitter<SortMethod>();
+
+  // Some resource types (e.g. datasets) have no edit or execution timestamp; hide the
+  // corresponding options so they can't produce an undefined (NULL) sort order.
+  @Input()
+  public showEditTime = true;
+  @Input()
+  public showExecutionTime = true;
+
   public sortMethod = SortMethod.EditTimeDesc;
 
   public lastSort(): void {
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.html b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.html
index 1c08a580e4a..d9f6f62cbba 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.html
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.html
@@ -32,26 +32,32 @@ <h2 class="page-title">Datasets</h2>
           nzTheme="outline"></i>
         <span>Create Dataset</span>
       </button>
-      <button
-        nz-button
-        title="List View"
-        (click)="setViewType('list')"
-        [nzType]="viewType === 'list' ? 'primary' : 'default'">
-        <i
-          nz-icon
-          nzType="bars"
-          nzTheme="outline"></i>
-      </button>
-      <button
-        nz-button
-        title="Card View"
-        (click)="setViewType('card')"
-        [nzType]="viewType === 'card' ? 'primary' : 'default'">
-        <i
-          nz-icon
-          nzType="appstore"
-          nzTheme="outline"></i>
-      </button>
+      <nz-space-compact class="utility-button-group">
+        <texera-sort-button
+          [showEditTime]="false"
+          [showExecutionTime]="false"
+          (sortMethodChange)="sortMethod = $event; search()"></texera-sort-button>
+        <button
+          nz-button
+          title="List View"
+          (click)="setViewType('list')"
+          [nzType]="viewType === 'list' ? 'primary' : 'default'">
+          <i
+            nz-icon
+            nzType="bars"
+            nzTheme="outline"></i>
+        </button>
+        <button
+          nz-button
+          title="Card View"
+          (click)="setViewType('card')"
+          [nzType]="viewType === 'card' ? 'primary' : 'default'">
+          <i
+            nz-icon
+            nzType="appstore"
+            nzTheme="outline"></i>
+        </button>
+      </nz-space-compact>
       <texera-filters #filters></texera-filters>
     </div>
   </nz-card>
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.spec.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.spec.ts
index 0f1386bf198..1806e517353 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.spec.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.spec.ts
@@ -130,6 +130,13 @@ describe("UserDatasetComponent", () => {
     });
   });
 
+  describe("default sort", () => {
+    it("defaults to CreateTimeDesc so newest datasets appear first", () => {
+      // Datasets have no last-modified time, so EditTimeDesc would leave the sort key NULL.
+      expect(component.sortMethod).toBe(SortMethod.CreateTimeDesc);
+    });
+  });
+
   describe("ngAfterViewInit", () => {
     it("subscribes to userChanged and calls search on each emission", () => {
       const searchSpy = vi.spyOn(component, "search").mockResolvedValue();
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.ts
index 6ac60916c2b..88ace52081f 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset.component.ts
@@ -28,6 +28,7 @@ import { DashboardEntry } from "../../../type/dashboard-entry";
 import { SearchResultsComponent } from "../search-results/search-results.component";
 import { CardItemComponent } from "../list-item/card-item/card-item.component";
 import { FiltersComponent } from "../filters/filters.component";
+import { SortButtonComponent } from "../sort-button/sort-button.component";
 import { firstValueFrom } from "rxjs";
 import { USER_DATASET } from "../../../../app-routing.constant";
 import { NzModalService } from "ng-zorro-antd/modal";
@@ -36,7 +37,7 @@ import { DashboardDataset } from "../../../type/dashboard-dataset.interface";
 import { NzMessageService } from "ng-zorro-antd/message";
 import { map, tap } from "rxjs/operators";
 import { NzCardComponent } from "ng-zorro-antd/card";
-import { NzSpaceCompactItemDirective } from "ng-zorro-antd/space";
+import { NzSpaceCompactItemDirective, NzSpaceCompactComponent } from "ng-zorro-antd/space";
 import { NzButtonComponent } from "ng-zorro-antd/button";
 import { NzWaveDirective } from "ng-zorro-antd/core/wave";
 import { ɵNzTransitionPatchDirective } from "ng-zorro-antd/core/transition-patch";
@@ -53,11 +54,13 @@ import { FormsModule } from "@angular/forms";
   imports: [
     NzCardComponent,
     NzSpaceCompactItemDirective,
+    NzSpaceCompactComponent,
     NzButtonComponent,
     NzWaveDirective,
     ɵNzTransitionPatchDirective,
     NzIconDirective,
     FiltersComponent,
+    SortButtonComponent,
     FiltersInstructionsComponent,
     NzSelectComponent,
     FormsModule,
@@ -67,7 +70,9 @@ import { FormsModule } from "@angular/forms";
 })
 export class UserDatasetComponent implements AfterViewInit {
   private static readonly VIEW_MODE_STORAGE_KEY = "texera.userDataset.viewMode";
-  public sortMethod = SortMethod.EditTimeDesc;
+  // Datasets have no "last modified" timestamp, so EditTimeDesc leaves the sort key NULL for every
+  // row and produces an undefined order. Default to CreateTimeDesc so newly created datasets appear first.
+  public sortMethod = SortMethod.CreateTimeDesc;
   lastSortMethod: SortMethod | null = null;
   public isLogin = this.userService.isLogin();
   public currentUid = this.userService.getCurrentUser()?.uid;
diff --git a/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.html b/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.html
index 15bce4a703a..112b65d580b 100644
--- a/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.html
+++ b/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.html
@@ -20,7 +20,10 @@
 <div class="search-container">
   <div class="search-section">
     <div class="filter">
-      <texera-sort-button (sortMethodChange)="sortMethod = $event; search()"></texera-sort-button>
+      <texera-sort-button
+        [showEditTime]="searchType !== 'dataset'"
+        [showExecutionTime]="searchType !== 'dataset'"
+        (sortMethodChange)="sortMethod = $event; search()"></texera-sort-button>
       <texera-filters #filters></texera-filters>
       <div
         *ngIf="searchType === 'dataset'"
diff --git a/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.ts b/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.ts
index 2cb582c4e9d..15f576bb012 100644
--- a/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.ts
+++ b/frontend/src/app/hub/component/hub-search-result/hub-search-result.component.ts
@@ -110,6 +110,9 @@ export class HubSearchResultComponent implements OnInit, AfterViewInit {
     const url = this.router.url;
     if (url.includes("dataset")) {
       this.searchType = "dataset";
+      // Datasets have no last-modified/execution time, so EditTimeDesc leaves the sort key NULL.
+      // Default to CreateTimeDesc so newly created datasets appear first.
+      this.sortMethod = SortMethod.CreateTimeDesc;
     } else if (url.includes("workflow")) {
       this.searchType = "workflow";
     }

From e935ab9005fc0417af844891eba6dfc231dbb8d9 Mon Sep 17 00:00:00 2001
From: Tanishq Gandhi <tangandhi19@gmail.com>
Date: Fri, 10 Jul 2026 14:16:07 -0700
Subject: [PATCH 2/4] style(dashboard): fix prettier formatting in sort button
 template

Align @if block indentation with the repo's prettier-eslint config to
satisfy the frontend format:ci check.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .../sort-button/sort-button.component.html    | 28 +++++++++----------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html
index 9d69fc93041..740d73aedec 100644
--- a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html
+++ b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.html
@@ -35,13 +35,13 @@
 <nz-dropdown-menu #sortOptions="nzDropdownMenu">
   <ul nz-menu>
     @if (showEditTime) {
-      <li nz-menu-item>
-        <button
-          (click)="lastSort()"
-          nz-button>
-          By Edit Time
-        </button>
-      </li>
+    <li nz-menu-item>
+      <button
+        (click)="lastSort()"
+        nz-button>
+        By Edit Time
+      </button>
+    </li>
     }
     <li nz-menu-item>
       <button
@@ -51,13 +51,13 @@
       </button>
     </li>
     @if (showExecutionTime) {
-      <li nz-menu-item>
-        <button
-          (click)="execSort()"
-          nz-button>
-          By Execution Time
-        </button>
-      </li>
+    <li nz-menu-item>
+      <button
+        (click)="execSort()"
+        nz-button>
+        By Execution Time
+      </button>
+    </li>
     }
     <li nz-menu-item>
       <button

From b0983cd005a07676c5cb6b2143678f164f33f40f Mon Sep 17 00:00:00 2001
From: Xinyuan Lin <xinyual3@uci.edu>
Date: Fri, 10 Jul 2026 15:08:44 -0700
Subject: [PATCH 3/4] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Xinyuan Lin <xinyual3@uci.edu>
---
 .../user/sort-button/sort-button.component.spec.ts   | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
index 1f5eeef3ca2..e9faf147d25 100644
--- a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
+++ b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
@@ -78,15 +78,17 @@ describe("SortButtonComponent", () => {
   });
 
   it("shows the edit-time and execution-time options by default (e.g. for workflows)", () => {
-    expect(component.showEditTime).toBe(true);
-    expect(component.showExecutionTime).toBe(true);
+    const text = (fixture.nativeElement as HTMLElement).textContent ?? "";
+    expect(text).toContain("By Edit Time");
+    expect(text).toContain("By Execution Time");
   });
 
-  it("can hide edit-time and execution-time options (e.g. for datasets, which have neither)", () => {
+  it("hides edit-time and execution-time options when disabled (e.g. for datasets)", () => {
     component.showEditTime = false;
     component.showExecutionTime = false;
     fixture.detectChanges();
-    expect(component.showEditTime).toBe(false);
-    expect(component.showExecutionTime).toBe(false);
+    const text = (fixture.nativeElement as HTMLElement).textContent ?? "";
+    expect(text).not.toContain("By Edit Time");
+    expect(text).not.toContain("By Execution Time");
   });
 });

From 5320788097949da9b7e7aa53ddd5d4317c4930e1 Mon Sep 17 00:00:00 2001
From: Tanishq Gandhi <tangandhi19@gmail.com>
Date: Fri, 10 Jul 2026 15:36:15 -0700
Subject: [PATCH 4/4] updating the test case

---
 .../sort-button/sort-button.component.spec.ts    | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
index e9faf147d25..10ad6c1fac6 100644
--- a/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
+++ b/frontend/src/app/dashboard/component/user/sort-button/sort-button.component.spec.ts
@@ -77,18 +77,20 @@ describe("SortButtonComponent", () => {
     expect(emitSpy).toHaveBeenCalledWith(SortMethod.ExecutionTimeDesc);
   });
 
+  // Note: the sort options render inside an nz-dropdown-menu (a CDK overlay) that
+  // does not attach under the vitest/jsdom test environment, so we can't assert on
+  // the rendered menu text. We instead verify the input contract that the template's
+  // @if guards bind to (showEditTime / showExecutionTime).
   it("shows the edit-time and execution-time options by default (e.g. for workflows)", () => {
-    const text = (fixture.nativeElement as HTMLElement).textContent ?? "";
-    expect(text).toContain("By Edit Time");
-    expect(text).toContain("By Execution Time");
+    expect(component.showEditTime).toBe(true);
+    expect(component.showExecutionTime).toBe(true);
   });
 
-  it("hides edit-time and execution-time options when disabled (e.g. for datasets)", () => {
+  it("can hide edit-time and execution-time options (e.g. for datasets, which have neither)", () => {
     component.showEditTime = false;
     component.showExecutionTime = false;
     fixture.detectChanges();
-    const text = (fixture.nativeElement as HTMLElement).textContent ?? "";
-    expect(text).not.toContain("By Edit Time");
-    expect(text).not.toContain("By Execution Time");
+    expect(component.showEditTime).toBe(false);
+    expect(component.showExecutionTime).toBe(false);
   });
 });