Prevent entity data from overflowing hover card (#1115)

Closes getodk/central#854.

src/components/dl-data.vue

@@ -43,6 +43,10 @@ defineProps({
 .dl-data-dt { @include text-overflow-ellipsis; }
 
 .dl-data-dd {
+  // This is needed for the line-clamp mixin to work if the component is used in
+  // .dl-horizontal. See: https://github.com/getodk/central/issues/854
+  overflow: hidden;
+
   div {
     @include line-clamp(3);
     overflow-wrap: break-word;

test/components/hover-card/entity.spec.js

@@ -0,0 +1,80 @@
+import DlData from '../../../src/components/dl-data.vue';
+import HoverCardEntity from '../../../src/components/hover-card/entity.vue';
+
+import useHoverCardResources from '../../../src/request-data/hover-card';
+
+import { truncatesText } from '../../../src/util/dom';
+
+import testData from '../../data';
+import { mergeMountOptions, mount } from '../../util/lifecycle';
+import { testRequestData } from '../../util/request-data';
+
+const mountComponent = (options = undefined) =>
+  mount(HoverCardEntity, mergeMountOptions(options, {
+    container: {
+      requestData: testRequestData([useHoverCardResources], {
+        dataset: testData.extendedDatasets.last(),
+        entity: testData.standardEntities.last()
+      })
+    }
+  }));
+
+describe('HoverCardEntity', () => {
+  describe('entity property data', () => {
+    it('shows the first 5 properties', () => {
+      testData.extendedEntities.createPast(1, {
+        data: { p1: 'a', p2: 'b', p3: 'c', p4: 'd', p5: 'e', p6: 'f' }
+      });
+      const props = mountComponent().findAllComponents(DlData)
+        .map(wrapper => wrapper.props());
+      props.should.eql([
+        { name: 'p1', value: 'a' },
+        { name: 'p2', value: 'b' },
+        { name: 'p3', value: 'c' },
+        { name: 'p4', value: 'd' },
+        { name: 'p5', value: 'e' }
+      ]);
+    });
+
+    it('renders correctly if there are fewer than 5 properties', () => {
+      testData.extendedEntities.createPast(1, {
+        data: { p1: 'a', p2: 'b' }
+      });
+      const props = mountComponent().findAllComponents(DlData)
+        .map(wrapper => wrapper.props());
+      props.should.eql([
+        { name: 'p1', value: 'a' },
+        { name: 'p2', value: 'b' }
+      ]);
+    });
+
+    it('truncates a long property name', () => {
+      testData.extendedEntities.createPast(1, {
+        data: { ['x'.repeat(1000)]: 'y' }
+      });
+      const component = mountComponent({ attachTo: document.body });
+      const body = component.get('.hover-card-body');
+      body.element.clientWidth.should.equal(288);
+      const dt = body.get('.dl-data-dt');
+      // The <dt> should get no more than 50% of the width of .hover-card-body.
+      dt.element.clientWidth.should.equal(144);
+      // It's not possible to mouse over a hover card in order to view a
+      // tooltip, so this is the best way to assert text truncation.
+      truncatesText(dt.element).should.be.true;
+      body.get('.dl-data-dd').element.clientWidth.should.equal(144);
+    });
+
+    it('truncates a long property value', () => {
+      testData.extendedEntities.createPast(1, {
+        data: { x: 'y'.repeat(1000) }
+      });
+      const component = mountComponent({ attachTo: document.body });
+      const body = component.get('.hover-card-body');
+      body.element.clientWidth.should.equal(288);
+      const dd = body.get('.dl-data-dd');
+      // More than 50% of the width of .hover-card-body, but well short of 100%
+      dd.element.clientWidth.should.be.within(180, 250);
+      truncatesText(dd.get('div').element).should.be.true;
+    });
+  });
+});