From 5659d10d7ccde929a23a7ae22a56df59a5f850ed Mon Sep 17 00:00:00 2001
From: Emil Ajdyna <emil@ajdyna.com>
Date: Fri, 5 Jan 2018 20:15:21 +0100
Subject: [PATCH] Allow xlink:href attribute

---
 src/validate/html/a11y.ts                     | 19 +++++++++-----
 .../a11y-anchor-in-svg-is-valid/input.html    |  3 +++
 .../a11y-anchor-in-svg-is-valid/warnings.json | 26 +++++++++++++++++++
 3 files changed, 42 insertions(+), 6 deletions(-)
 create mode 100644 test/validator/samples/a11y-anchor-in-svg-is-valid/input.html
 create mode 100644 test/validator/samples/a11y-anchor-in-svg-is-valid/warnings.json

diff --git a/src/validate/html/a11y.ts b/src/validate/html/a11y.ts
index 71df223d5ec7..4dbf249fff1e 100644
--- a/src/validate/html/a11y.ts
+++ b/src/validate/html/a11y.ts
@@ -106,14 +106,21 @@ export default function a11y(
 		}
 	}
 
+	function shouldHaveValidHref (attribute) {
+		const href = attributeMap.get(attribute);
+		const value = getStaticAttributeValue(node, attribute);
+		if (value === '' || value === '#') {
+			validator.warn(`A11y: '${value}' is not a valid ${attribute} attribute`, href.start);
+		}
+	}
+
 	if (node.name === 'a') {
-		// anchor-is-valid
-		const href = attributeMap.get('href');
 		if (attributeMap.has('href')) {
-			const value = getStaticAttributeValue(node, 'href');
-			if (value === '' || value === '#') {
-				validator.warn(`A11y: '${value}' is not a valid href attribute`, href.start);
-			}
+			// anchor-is-valid
+			shouldHaveValidHref('href')
+		} else if (attributeMap.has('xlink:href')) {
+			// anchor-in-svg-is-valid
+			shouldHaveValidHref('xlink:href')
 		} else {
 			validator.warn(`A11y: <a> element should have an href attribute`, node.start);
 		}
diff --git a/test/validator/samples/a11y-anchor-in-svg-is-valid/input.html b/test/validator/samples/a11y-anchor-in-svg-is-valid/input.html
new file mode 100644
index 000000000000..48a5599aa204
--- /dev/null
+++ b/test/validator/samples/a11y-anchor-in-svg-is-valid/input.html
@@ -0,0 +1,3 @@
+<svg><text><a>not actually a link</a></text></svg>
+<svg><text><a xlink:href=''>not actually a link</a></text></svg>
+<svg><text><a xlink:href='#'>not actually a link</a></text></svg>
diff --git a/test/validator/samples/a11y-anchor-in-svg-is-valid/warnings.json b/test/validator/samples/a11y-anchor-in-svg-is-valid/warnings.json
new file mode 100644
index 000000000000..1e65bc4986e7
--- /dev/null
+++ b/test/validator/samples/a11y-anchor-in-svg-is-valid/warnings.json
@@ -0,0 +1,26 @@
+[
+  {
+    "message": "A11y: <a> element should have an href attribute",
+    "loc": {
+      "line": 1,
+      "column": 11
+    },
+    "pos": 11
+  },
+  {
+    "message": "A11y: '' is not a valid xlink:href attribute",
+    "loc": {
+      "line": 2,
+      "column": 14
+    },
+    "pos": 65
+  },
+  {
+    "message": "A11y: '#' is not a valid xlink:href attribute",
+    "loc": {
+      "line": 3,
+      "column": 14
+    },
+    "pos": 130
+  }
+]