Fix Error Summary component outputting list HTML when no errorList is provided

CHANGELOG.md

@@ -42,7 +42,7 @@ It was previously only possible to use tabular numbers by using the `govuk-font-
 
 This change was introduced in [pull request #4973: Add override class for tabular numbers](https://github.com/alphagov/govuk-frontend/pull/4973).
 
-### Deprecations
+### Deprecated features
 
 #### Importing layers using `all` files
 
@@ -70,6 +70,7 @@ We've made fixes to GOV.UK Frontend in the following pull requests:
 - [#4942: Remove duplicate `errorMessage` argument for the password input component](https://github.com/alphagov/govuk-frontend/pull/4942) - thanks to [Tim South](https://github.com/tim-s-ccs) for contributing this change
 - [#4961: Fix tree-shaking when importing `govuk-frontend`](https://github.com/alphagov/govuk-frontend/pull/4961)
 - [#4963: Fix input value not being set if the value was '0'](https://github.com/alphagov/govuk-frontend/pull/4963) – thanks to [@dwp-dmitri-algazin](https://github.com/dwp-dmitri-algazin) for reporting this issue
+- [#4971: Fix Error Summary component outputting list HTML when no `errorList` is provided](https://github.com/alphagov/govuk-frontend/pull/4971)
 
 ## 5.3.1 (Fix release)
 

packages/govuk-frontend/src/govuk/components/error-summary/_index.scss

@@ -24,14 +24,21 @@
 
   .govuk-error-summary__body {
     p {
-      margin-top: 0;
-      @include govuk-responsive-margin(4, "bottom");
+      margin-bottom: 0;
+    }
+
+    > * + * {
+      @include govuk-responsive-margin(4, "top");
     }
   }
 
   // Cross-component class - adjusts styling of list component
   .govuk-error-summary__list {
-    margin-top: 0;
+    margin-bottom: 0;
+  }
+
+  // Remove the bottom margin from the last list item
+  .govuk-error-summary__list li:last-child {
     margin-bottom: 0;
   }
 

packages/govuk-frontend/src/govuk/components/error-summary/error-summary.yaml

@@ -21,8 +21,8 @@ params:
     description: Not strictly a parameter but [Nunjucks code convention](https://mozilla.github.io/nunjucks/templating.html#call). Using a `call` block enables you to call a macro with all the text inside the tag. This is helpful if you want to pass a lot of content into a macro. To use it, you will need to wrap the entire error summary component in a `call` block.
   - name: errorList
     type: array
-    required: true
-    description: The list of errors to include in the error summary.
+    required: false
+    description: A list of errors to include in the error summary.
     params:
       - name: href
         type: string
@@ -77,6 +77,10 @@ examples:
         - text: Invalid username or password
         - text: Agree to the terms of service to log in
           href: '#example-error-1'
+  - name: with description only
+    options:
+      titleText: There is a problem
+      descriptionText: The file couldn't be loaded. Try again later.
   - name: with everything
     options:
       titleText: There is a problem

packages/govuk-frontend/src/govuk/components/error-summary/template.njk

@@ -16,20 +16,22 @@
         {{ caller() if caller else (params.descriptionHtml | safe | trim | indent(8) if params.descriptionHtml else params.descriptionText) }}
       </p>
       {% endif %}
-      <ul class="govuk-list govuk-error-summary__list">
-      {% for item in params.errorList %}
-        <li>
-        {% if item.href %}
-          <a href="{{ item.href }}"
-            {{- govukAttributes(item.attributes) }}>
-            {{- item.html | safe | trim | indent(12) if item.html else item.text -}}
-          </a>
-        {% else %}
-          {{ item.html | safe | trim | indent(10) if item.html else item.text }}
-        {% endif %}
-        </li>
-      {% endfor %}
-      </ul>
+      {% if params.errorList | length %}
+        <ul class="govuk-list govuk-error-summary__list">
+        {% for item in params.errorList %}
+          <li>
+          {% if item.href %}
+            <a href="{{ item.href }}"
+              {{- govukAttributes(item.attributes) }}>
+              {{- item.html | safe | trim | indent(12) if item.html else item.text -}}
+            </a>
+          {% else %}
+            {{ item.html | safe | trim | indent(10) if item.html else item.text }}
+          {% endif %}
+          </li>
+        {% endfor %}
+        </ul>
+      {% endif %}
     </div>
   </div>
 </div>

packages/govuk-frontend/src/govuk/components/error-summary/template.test.js

@@ -25,6 +25,13 @@ describe('Error-summary', () => {
       expect(summaryTitle).toBe('There is a problem')
     })
 
+    it('renders error list element', () => {
+      const $ = render('error-summary', examples.default)
+      const $errorList = $('.govuk-error-summary__list')
+
+      expect($errorList).toHaveLength(1)
+    })
+
     it('number of error items matches the number of items specified', () => {
       const $ = render('error-summary', examples.default)
       const errorList = $('.govuk-error-summary .govuk-error-summary__list li')
@@ -112,6 +119,13 @@ describe('Error-summary', () => {
       expect($component.attr('second-attribute')).toBe('bar')
     })
 
+    it("doesn't render the error list element if no errors are passed", () => {
+      const $ = render('error-summary', examples['with description only'])
+      const $errorList = $('.govuk-error-summary__list')
+
+      expect($errorList).toHaveLength(0)
+    })
+
     it('renders anchor tag with attributes', () => {
       const $ = render('error-summary', examples['error list with attributes'])