1 files changed, 35 insertions, 0 deletions
diff --git a/spec/javascripts/matchers.js b/spec/javascripts/matchers.js
new file mode 100644
index 00000000000..7cc5e753c22
--- /dev/null
+++ b/spec/javascripts/matchers.js
@@ -0,0 +1,35 @@
+export default {
+  toHaveSpriteIcon: () => ({
+    compare(element, iconName) {
+      if (!iconName) {
+        throw new Error('toHaveSpriteIcon is missing iconName argument!');
+      }
+
+      if (!(element instanceof HTMLElement)) {
+        throw new Error(`${element} is not a DOM element!`);
+      }
+
+      const iconReferences = [].slice.apply(element.querySelectorAll('svg use'));
+      const matchingIcon = iconReferences.find(reference => reference.getAttribute('xlink:href').endsWith(`#${iconName}`));
+      const result = {
+        pass: !!matchingIcon,
+      };
+
+      if (result.pass) {
+        result.message = `${element.outerHTML} contains the sprite icon "${iconName}"!`;
+      } else {
+        result.message = `${element.outerHTML} does not contain the sprite icon "${iconName}"!`;
+
+        const existingIcons = iconReferences.map((reference) => {
+          const iconUrl = reference.getAttribute('xlink:href');
+          return `"${iconUrl.replace(/^.+#/, '')}"`;
+        });
+        if (existingIcons.length > 0) {
+          result.message += ` (only found ${existingIcons.join(',')})`;
+        }
+      }
+
+      return result;
+    },
+  }),
+};