From 373efcbe3e5edd52c03b74fd36df7cf96f9fc3bf Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Mon, 27 Dec 2021 23:09:19 +0000
Subject: [PATCH 01/17] add a redundant roles compiler warning

---
 src/compiler/compile/compiler_warnings.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/compiler/compile/compiler_warnings.ts b/src/compiler/compile/compiler_warnings.ts
index bfcd779fc7ea..9413bce3602d 100644
--- a/src/compiler/compile/compiler_warnings.ts
+++ b/src/compiler/compile/compiler_warnings.ts
@@ -76,6 +76,10 @@ export default {
 		code: 'a11y-unknown-role',
 		message: `A11y: Unknown role '${role}'` + (suggestion ? ` (did you mean '${suggestion}'?)` : '')
 	}),
+	a11y_no_redundant_roles: (role: string | boolean , suggestion?: string) => ({
+		code: 'a11y-no-redundant-roles',
+		message: `A11y: Redundant role '${role}'` + (suggestion ? ` (did you mean '${suggestion})?'` : '')
+	}),
 	a11y_accesskey: {
 		code: 'a11y-accesskey',
 		message: 'A11y: Avoid using accesskey'

From 7eeca8e364de0d6c9d45bd89d9ab7798bc7e6a5c Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Mon, 27 Dec 2021 23:09:54 +0000
Subject: [PATCH 02/17] add a test case for redundant roles

---
 .../validator/samples/a11y-no-redundant-roles/input.svelte | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 test/validator/samples/a11y-no-redundant-roles/input.svelte

diff --git a/test/validator/samples/a11y-no-redundant-roles/input.svelte b/test/validator/samples/a11y-no-redundant-roles/input.svelte
new file mode 100644
index 000000000000..409577c9114a
--- /dev/null
+++ b/test/validator/samples/a11y-no-redundant-roles/input.svelte
@@ -0,0 +1,7 @@
+<button role="button" />
+<nav role="navigation" />
+<a href='/' role="link">a link</a>
+
+<header role='banner'></header>
+<footer role='contentinfo'></footer>
+<main role='main'></main>

From f7bc2c71e5a0e3299d001c4e874392dc7072225a Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Mon, 27 Dec 2021 23:10:03 +0000
Subject: [PATCH 03/17] add validators for a11y-redundant-roles

---
 src/compiler/compile/nodes/Element.ts | 48 +++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 837a0296d097..146d3157942f 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -351,6 +351,54 @@ export default class Element extends Node {
 					const match = fuzzymatch(value, aria_roles);
 					component.warn(attribute, compiler_warnings.a11y_unknown_role(value, match));
 				}
+
+				// no-redundant-roles
+				// https://www.w3.org/TR/html-aria/#don-t-add-redundant-roles
+				if (this.name === value) {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+				if (this.name === 'nav' && value === 'navigation') {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+
+				if (this.name === 'a' && value === 'link') {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+
+				if (this.name === 'fieldset' && value === 'group') {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+
+				if (this.name === 'ul' && value === 'list') {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+
+				if (this.name === 'main' && value === 'main') {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+
+				let { parent } = this;
+				let is_parent_section_or_article = false;
+
+				while (parent) {
+					let parent_name = (parent as Element).name
+					if ( parent_name === 'section' || parent_name === 'article') {
+						is_parent_section_or_article = true;
+						break;
+					}
+					if (parent.type === 'Element') {
+						break;
+					}
+					parent = parent.parent;
+				}
+
+				if (this.name === 'header' && value === 'banner' && !is_parent_section_or_article) {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
+
+				if (this.name === 'footer' && value === 'contentinfo' && !is_parent_section_or_article) {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+				}
 			}
 
 			// no-access-key

From 669174861d1be873894c326f28cdbf8cccde898e Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Tue, 28 Dec 2021 18:47:28 +0000
Subject: [PATCH 04/17] add warnings to check against

---
 .../a11y-no-redundant-roles/warnings.json     | 107 ++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 test/validator/samples/a11y-no-redundant-roles/warnings.json

diff --git a/test/validator/samples/a11y-no-redundant-roles/warnings.json b/test/validator/samples/a11y-no-redundant-roles/warnings.json
new file mode 100644
index 000000000000..22a60f9684c7
--- /dev/null
+++ b/test/validator/samples/a11y-no-redundant-roles/warnings.json
@@ -0,0 +1,107 @@
+[
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 21,
+            "column": 21,
+            "line": 1
+        },
+        "message": "A11y: Redundant role 'button'",
+        "pos": 8,
+        "start": {
+            "character": 8,
+            "column": 8,
+            "line": 1
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 47,
+            "column": 22,
+            "line": 2
+        },
+        "message": "A11y: Redundant role 'navigation'",
+        "pos": 30,
+        "start": {
+            "character": 30,
+            "column": 5,
+            "line": 2
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 74,
+            "column": 23,
+            "line": 3
+        },
+        "message": "A11y: Redundant role 'link'",
+        "pos": 63,
+        "start": {
+            "character": 63,
+            "column": 12,
+            "line": 3
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 108,
+            "column": 21,
+            "line": 5
+        },
+        "message": "A11y: Redundant role 'banner'",
+        "pos": 95,
+        "start": {
+            "character": 95,
+            "column": 8,
+            "line": 5
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 145,
+            "column": 26,
+            "line": 6
+        },
+        "message": "A11y: Redundant role 'contentinfo'",
+        "pos": 127,
+        "start": {
+            "character": 127,
+            "column": 8,
+            "line": 6
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 173,
+            "column": 17,
+            "line": 7
+        },
+        "message": "A11y: Redundant role 'main'",
+        "pos": 162,
+        "start": {
+            "character": 162,
+            "column": 6,
+            "line": 7
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 173,
+            "column": 17,
+            "line": 7
+        },
+        "message": "A11y: Redundant role 'main'",
+        "pos": 162,
+        "start": {
+            "character": 162,
+            "column": 6,
+            "line": 7
+        }
+    }
+]
\ No newline at end of file

From 12afce72bfb279d2051a7e79b9e684165b9f08dc Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Tue, 28 Dec 2021 18:48:30 +0000
Subject: [PATCH 05/17] remove code comments that are extraneous

---
 src/compiler/compile/nodes/Element.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 146d3157942f..3c8084b48fc9 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -353,7 +353,6 @@ export default class Element extends Node {
 				}
 
 				// no-redundant-roles
-				// https://www.w3.org/TR/html-aria/#don-t-add-redundant-roles
 				if (this.name === value) {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
 				}

From 30c03524104cf08314ae907d3f605d599475fd32 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Tue, 28 Dec 2021 18:51:51 +0000
Subject: [PATCH 06/17] correct linting issues

---
 src/compiler/compile/nodes/Element.ts | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 3c8084b48fc9..7e488682d40a 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -354,33 +354,33 @@ export default class Element extends Node {
 
 				// no-redundant-roles
 				if (this.name === value) {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 				if (this.name === 'nav' && value === 'navigation') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				if (this.name === 'a' && value === 'link') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				if (this.name === 'fieldset' && value === 'group') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				if (this.name === 'ul' && value === 'list') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				if (this.name === 'main' && value === 'main') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				let { parent } = this;
 				let is_parent_section_or_article = false;
 
 				while (parent) {
-					let parent_name = (parent as Element).name
+					const parent_name = (parent as Element).name;
 					if ( parent_name === 'section' || parent_name === 'article') {
 						is_parent_section_or_article = true;
 						break;
@@ -392,11 +392,11 @@ export default class Element extends Node {
 				}
 
 				if (this.name === 'header' && value === 'banner' && !is_parent_section_or_article) {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				if (this.name === 'footer' && value === 'contentinfo' && !is_parent_section_or_article) {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value))
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 			}
 

From db606c7a922e3e30d3f1bd3e68f6520f745d494a Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 12:30:22 +0000
Subject: [PATCH 07/17] remove suggestion from compiler warning

---
 src/compiler/compile/compiler_warnings.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler/compile/compiler_warnings.ts b/src/compiler/compile/compiler_warnings.ts
index 9413bce3602d..86ec98cb8b16 100644
--- a/src/compiler/compile/compiler_warnings.ts
+++ b/src/compiler/compile/compiler_warnings.ts
@@ -76,9 +76,9 @@ export default {
 		code: 'a11y-unknown-role',
 		message: `A11y: Unknown role '${role}'` + (suggestion ? ` (did you mean '${suggestion}'?)` : '')
 	}),
-	a11y_no_redundant_roles: (role: string | boolean , suggestion?: string) => ({
+	a11y_no_redundant_roles: (role: string | boolean) => ({
 		code: 'a11y-no-redundant-roles',
-		message: `A11y: Redundant role '${role}'` + (suggestion ? ` (did you mean '${suggestion})?'` : '')
+		message: `A11y: Redundant role '${role}'`
 	}),
 	a11y_accesskey: {
 		code: 'a11y-accesskey',

From 91ec3fcb7b2216d338a19b2b1cbe77718e14778a Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 12:31:06 +0000
Subject: [PATCH 08/17] abstract parent element check into function

---
 src/compiler/compile/nodes/Element.ts | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 7e488682d40a..0d5dbe7c3e42 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -98,6 +98,23 @@ const react_attributes = new Map([
 
 const attributes_to_compact_whitespace = ['class', 'style'];
 
+function is_parent(parent: INode, elements: Array<string>) {
+	let check = false;
+
+	while (parent) {
+		const parent_name = (parent as Element).name;
+		if (elements.includes(parent_name)) {
+			check = true;
+			break;
+		}
+		if (parent.type === 'Element') {
+			break;
+		}
+		parent = parent.parent;
+	}
+	return check;
+}
+
 function get_namespace(parent: Element, element: Element, explicit_namespace: string) {
 	const parent_element = parent.find_nearest(/^Element/);
 
@@ -376,14 +393,7 @@ export default class Element extends Node {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
-				let { parent } = this;
-				let is_parent_section_or_article = false;
-
-				while (parent) {
-					const parent_name = (parent as Element).name;
-					if ( parent_name === 'section' || parent_name === 'article') {
-						is_parent_section_or_article = true;
-						break;
+				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article'])
 					}
 					if (parent.type === 'Element') {
 						break;

From 53b89192c28eac9da8d2b5e248775ded689a8d54 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 12:31:48 +0000
Subject: [PATCH 09/17] nest article/section checks into an if statement

---
 src/compiler/compile/nodes/Element.ts | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 0d5dbe7c3e42..f9e6f7d8bb56 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -394,19 +394,14 @@ export default class Element extends Node {
 				}
 
 				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article'])
+				if (!is_parent_section_or_article) {
+					if (this.name === 'header' && value === 'banner') {
+						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}
-					if (parent.type === 'Element') {
-						break;
+	
+					else if (this.name === 'footer' && value === 'contentinfo') {
+						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}
-					parent = parent.parent;
-				}
-
-				if (this.name === 'header' && value === 'banner' && !is_parent_section_or_article) {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
-
-				if (this.name === 'footer' && value === 'contentinfo' && !is_parent_section_or_article) {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 			}
 

From 17906c2743b46f4ebd6a35666da73705b3edecf9 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 12:31:57 +0000
Subject: [PATCH 10/17] use else if where possible

---
 src/compiler/compile/nodes/Element.ts | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index f9e6f7d8bb56..69ce5ac9a615 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -373,23 +373,19 @@ export default class Element extends Node {
 				if (this.name === value) {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
-				if (this.name === 'nav' && value === 'navigation') {
+				else if (this.name === 'nav' && value === 'navigation') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
-				if (this.name === 'a' && value === 'link') {
+				else if (this.name === 'a' && value === 'link') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
-				if (this.name === 'fieldset' && value === 'group') {
+				else if (this.name === 'fieldset' && value === 'group') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
-				if (this.name === 'ul' && value === 'list') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
-
-				if (this.name === 'main' && value === 'main') {
+				else if (this.name === 'ul' && value === 'list') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 

From 649e462c92413b9c1e03570766d405e1896a0de8 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 12:34:52 +0000
Subject: [PATCH 11/17] linting suggestions

---
 src/compiler/compile/nodes/Element.ts | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 69ce5ac9a615..4c267697f5a6 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -98,7 +98,7 @@ const react_attributes = new Map([
 
 const attributes_to_compact_whitespace = ['class', 'style'];
 
-function is_parent(parent: INode, elements: Array<string>) {
+function is_parent(parent: INode, elements: string[]) {
 	let check = false;
 
 	while (parent) {
@@ -372,30 +372,21 @@ export default class Element extends Node {
 				// no-redundant-roles
 				if (this.name === value) {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
-				else if (this.name === 'nav' && value === 'navigation') {
+				} else if (this.name === 'nav' && value === 'navigation') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
-
-				else if (this.name === 'a' && value === 'link') {
+				} else if (this.name === 'a' && value === 'link') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
-
-				else if (this.name === 'fieldset' && value === 'group') {
+				} else if (this.name === 'fieldset' && value === 'group') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
-
-				else if (this.name === 'ul' && value === 'list') {
+				} else if (this.name === 'ul' && value === 'list') {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
-				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article'])
+				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article']);
 				if (!is_parent_section_or_article) {
 					if (this.name === 'header' && value === 'banner') {
 						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-					}
-	
-					else if (this.name === 'footer' && value === 'contentinfo') {
+					} else if (this.name === 'footer' && value === 'contentinfo') {
 						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}
 				}

From b6060f35201e1c1618d8b114b6579929fe69cd3f Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 17:45:31 +0000
Subject: [PATCH 12/17] update test to reflect unduplicated warnings

---
 .../samples/a11y-no-redundant-roles/warnings.json | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/test/validator/samples/a11y-no-redundant-roles/warnings.json b/test/validator/samples/a11y-no-redundant-roles/warnings.json
index 22a60f9684c7..d3358dd97ba8 100644
--- a/test/validator/samples/a11y-no-redundant-roles/warnings.json
+++ b/test/validator/samples/a11y-no-redundant-roles/warnings.json
@@ -74,21 +74,6 @@
             "line": 6
         }
     },
-    {
-        "code": "a11y-no-redundant-roles",
-        "end": {
-            "character": 173,
-            "column": 17,
-            "line": 7
-        },
-        "message": "A11y: Redundant role 'main'",
-        "pos": 162,
-        "start": {
-            "character": 162,
-            "column": 6,
-            "line": 7
-        }
-    },
     {
         "code": "a11y-no-redundant-roles",
         "end": {

From bb975e7b0c9a60477ed3daa5ea2b803505503141 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Thu, 30 Dec 2021 17:45:46 +0000
Subject: [PATCH 13/17] simplify conditional logic

---
 src/compiler/compile/nodes/Element.ts | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 4c267697f5a6..834d8aa1bde0 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -370,23 +370,17 @@ export default class Element extends Node {
 				}
 
 				// no-redundant-roles
-				if (this.name === value) {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				} else if (this.name === 'nav' && value === 'navigation') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				} else if (this.name === 'a' && value === 'link') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				} else if (this.name === 'fieldset' && value === 'group') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				} else if (this.name === 'ul' && value === 'list') {
-					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-				}
+				if (this.name === value || 
+					this.name === 'nav' && value === 'navigation' ||
+					this.name === 'a' && value === 'link' ||
+					this.name === 'fieldset' && value === 'group' ||
+					this.name === 'ul' && value === 'list') {
+						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
+					}
 
 				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article']);
 				if (!is_parent_section_or_article) {
-					if (this.name === 'header' && value === 'banner') {
-						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-					} else if (this.name === 'footer' && value === 'contentinfo') {
+					if (this.name === 'header' && value === 'banner' || this.name === 'footer' && value === 'contentinfo') {
 						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}
 				}

From 7c0b63f0c594f6e09c127dd6e158ec633f5aad9a Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Fri, 31 Dec 2021 14:01:07 +0000
Subject: [PATCH 14/17] include more conditions from PR #5361

---
 src/compiler/compile/nodes/Element.ts | 58 ++++++++++++++++++++++-----
 1 file changed, 49 insertions(+), 9 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 834d8aa1bde0..19e563026293 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -370,17 +370,57 @@ export default class Element extends Node {
 				}
 
 				// no-redundant-roles
-				if (this.name === value || 
-					this.name === 'nav' && value === 'navigation' ||
-					this.name === 'a' && value === 'link' ||
-					this.name === 'fieldset' && value === 'group' ||
-					this.name === 'ul' && value === 'list') {
-						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
-					}
-
+				const implicit_semantics = new Map([
+					['a', 'link'],
+					['article', 'article'],
+					['aside', 'complementary'],
+					['body', 'document'],
+					['datalist', 'listbox'],
+					['dd', 'definition'],
+					['dfn', 'term'],
+					['details', 'group'],
+					['dt', 'term'],
+					['fieldset', 'group'],
+					['form', 'form'],
+					['h1', 'heading'],
+					['h2', 'heading'],
+					['h3', 'heading'],
+					['h4', 'heading'],
+					['h5', 'heading'],
+					['h6', 'heading'],
+					['hr', 'separator'],
+					['li', 'listitem'],
+					['menu', 'list'],
+					['nav', 'navigation'],
+					['ol', 'list'],
+					['optgroup', 'group'],
+					['output', 'status'],
+					['progress', 'progressbar'],
+					['section', 'region'],
+					['summary', 'button'],
+					['tbody', 'rowgroup'],
+					['textarea', 'textbox'],
+					['tfoot', 'rowgroup'],
+					['thead', 'rowgroup'],
+					['tr', 'row'],
+					['ul', 'list']
+				]);
+
+				const has_redundant_role = value === implicit_semantics.get(this.name);
+
+				if (this.name === value || has_redundant_role) {
+					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
+				}
+
+				// Footers and headers are special cases, and should not have redundant roles unless they are the children of sections or articles.
+				const nested_implicit_semantics = new Map([
+					['header', 'banner'],
+					['footer', 'contentinfo']
+				]);
 				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article']);
 				if (!is_parent_section_or_article) {
-					if (this.name === 'header' && value === 'banner' || this.name === 'footer' && value === 'contentinfo') {
+					const has_nested_redundant_role = value === nested_implicit_semantics.get(this.name);
+					if (has_nested_redundant_role) {
 						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}
 				}

From fdfbbed22f53461bda6c67d423c140d64fa930a5 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Fri, 31 Dec 2021 14:01:20 +0000
Subject: [PATCH 15/17] update test to reflect more cases that can be checked

---
 .../a11y-no-redundant-roles/input.svelte      |  45 +-
 .../a11y-no-redundant-roles/warnings.json     | 606 +++++++++++++++++-
 2 files changed, 614 insertions(+), 37 deletions(-)

diff --git a/test/validator/samples/a11y-no-redundant-roles/input.svelte b/test/validator/samples/a11y-no-redundant-roles/input.svelte
index 409577c9114a..05525effb628 100644
--- a/test/validator/samples/a11y-no-redundant-roles/input.svelte
+++ b/test/validator/samples/a11y-no-redundant-roles/input.svelte
@@ -1,7 +1,44 @@
+<a href="/" role="link">a link</a>
+<article role="article" />
+<aside role="complementary" />
+<body role="document" />
 <button role="button" />
+<datalist role="listbox" />
+<dd role="definition" />
+<dfn role="term" />
+<details role="group" />
+<dialog role="dialog" />
+<dt role="term" />
+<fieldset role="group" />
+<figure role="figure" />
+<form role="form">foo</form>
+<h1 role="heading">heading</h1>
+<h2 role="heading">heading</h2>
+<h3 role="heading">heading</h3>
+<h4 role="heading">heading</h4>
+<h5 role="heading">heading</h5>
+<h6 role="heading">heading</h6>
+<hr role="separator" />
+<li role="listitem" />
+<link role="link" />
+<main role="main"></main>
+<menu role="list" />
 <nav role="navigation" />
-<a href='/' role="link">a link</a>
+<ol role="list" />
+<optgroup role="group" />
+<option role="option" />
+<output role="status" />
+<progress role="progressbar" />
+<section role="region" />
+<summary role="button" />
+<table role="table" />
+<tbody role="rowgroup" />
+<textarea role="textbox" />
+<tfoot role="rowgroup" />
+<thead role="rowgroup" />
+<tr role="row" />
+<ul role="list" />
 
-<header role='banner'></header>
-<footer role='contentinfo'></footer>
-<main role='main'></main>
+<!-- Tested header/footer not nested in section/article -->
+<header role="banner"></header>
+<footer role="contentinfo"></footer>
\ No newline at end of file
diff --git a/test/validator/samples/a11y-no-redundant-roles/warnings.json b/test/validator/samples/a11y-no-redundant-roles/warnings.json
index d3358dd97ba8..8aa3520b3239 100644
--- a/test/validator/samples/a11y-no-redundant-roles/warnings.json
+++ b/test/validator/samples/a11y-no-redundant-roles/warnings.json
@@ -2,59 +2,74 @@
     {
         "code": "a11y-no-redundant-roles",
         "end": {
-            "character": 21,
-            "column": 21,
+            "character": 23,
+            "column": 23,
             "line": 1
         },
-        "message": "A11y: Redundant role 'button'",
-        "pos": 8,
+        "message": "A11y: Redundant role 'link'",
+        "pos": 12,
         "start": {
-            "character": 8,
-            "column": 8,
+            "character": 12,
+            "column": 12,
             "line": 1
         }
     },
     {
         "code": "a11y-no-redundant-roles",
         "end": {
-            "character": 47,
-            "column": 22,
+            "character": 58,
+            "column": 23,
             "line": 2
         },
-        "message": "A11y: Redundant role 'navigation'",
-        "pos": 30,
+        "message": "A11y: Redundant role 'article'",
+        "pos": 44,
         "start": {
-            "character": 30,
-            "column": 5,
+            "character": 44,
+            "column": 9,
             "line": 2
         }
     },
     {
         "code": "a11y-no-redundant-roles",
         "end": {
-            "character": 74,
-            "column": 23,
+            "character": 89,
+            "column": 27,
             "line": 3
         },
-        "message": "A11y: Redundant role 'link'",
-        "pos": 63,
+        "message": "A11y: Redundant role 'complementary'",
+        "pos": 69,
         "start": {
-            "character": 63,
-            "column": 12,
+            "character": 69,
+            "column": 7,
             "line": 3
         }
     },
     {
         "code": "a11y-no-redundant-roles",
         "end": {
-            "character": 108,
+            "character": 114,
+            "column": 21,
+            "line": 4
+        },
+        "message": "A11y: Redundant role 'document'",
+        "pos": 99,
+        "start": {
+            "character": 99,
+            "column": 6,
+            "line": 4
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 139,
             "column": 21,
             "line": 5
         },
-        "message": "A11y: Redundant role 'banner'",
-        "pos": 95,
+        "message": "A11y: Redundant role 'button'",
+        "pos": 126,
         "start": {
-            "character": 95,
+            "character": 126,
             "column": 8,
             "line": 5
         }
@@ -62,31 +77,556 @@
     {
         "code": "a11y-no-redundant-roles",
         "end": {
-            "character": 145,
-            "column": 26,
+            "character": 167,
+            "column": 24,
             "line": 6
         },
-        "message": "A11y: Redundant role 'contentinfo'",
-        "pos": 127,
+        "message": "A11y: Redundant role 'listbox'",
+        "pos": 153,
         "start": {
-            "character": 127,
-            "column": 8,
+            "character": 153,
+            "column": 10,
             "line": 6
         }
     },
     {
         "code": "a11y-no-redundant-roles",
         "end": {
-            "character": 173,
-            "column": 17,
+            "character": 192,
+            "column": 21,
             "line": 7
         },
+        "message": "A11y: Redundant role 'definition'",
+        "pos": 175,
+        "start": {
+            "character": 175,
+            "column": 4,
+            "line": 7
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 212,
+            "column": 16,
+            "line": 8
+        },
+        "message": "A11y: Redundant role 'term'",
+        "pos": 201,
+        "start": {
+            "character": 201,
+            "column": 5,
+            "line": 8
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 237,
+            "column": 21,
+            "line": 9
+        },
+        "message": "A11y: Redundant role 'group'",
+        "pos": 225,
+        "start": {
+            "character": 225,
+            "column": 9,
+            "line": 9
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 262,
+            "column": 21,
+            "line": 10
+        },
+        "message": "A11y: Redundant role 'dialog'",
+        "pos": 249,
+        "start": {
+            "character": 249,
+            "column": 8,
+            "line": 10
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 281,
+            "column": 15,
+            "line": 11
+        },
+        "message": "A11y: Redundant role 'term'",
+        "pos": 270,
+        "start": {
+            "character": 270,
+            "column": 4,
+            "line": 11
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 307,
+            "column": 22,
+            "line": 12
+        },
+        "message": "A11y: Redundant role 'group'",
+        "pos": 295,
+        "start": {
+            "character": 295,
+            "column": 10,
+            "line": 12
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 332,
+            "column": 21,
+            "line": 13
+        },
+        "message": "A11y: Redundant role 'figure'",
+        "pos": 319,
+        "start": {
+            "character": 319,
+            "column": 8,
+            "line": 13
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 353,
+            "column": 17,
+            "line": 14
+        },
+        "message": "A11y: Redundant role 'form'",
+        "pos": 342,
+        "start": {
+            "character": 342,
+            "column": 6,
+            "line": 14
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 383,
+            "column": 18,
+            "line": 15
+        },
+        "message": "A11y: Redundant role 'heading'",
+        "pos": 369,
+        "start": {
+            "character": 369,
+            "column": 4,
+            "line": 15
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 415,
+            "column": 18,
+            "line": 16
+        },
+        "message": "A11y: Redundant role 'heading'",
+        "pos": 401,
+        "start": {
+            "character": 401,
+            "column": 4,
+            "line": 16
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 447,
+            "column": 18,
+            "line": 17
+        },
+        "message": "A11y: Redundant role 'heading'",
+        "pos": 433,
+        "start": {
+            "character": 433,
+            "column": 4,
+            "line": 17
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 479,
+            "column": 18,
+            "line": 18
+        },
+        "message": "A11y: Redundant role 'heading'",
+        "pos": 465,
+        "start": {
+            "character": 465,
+            "column": 4,
+            "line": 18
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 511,
+            "column": 18,
+            "line": 19
+        },
+        "message": "A11y: Redundant role 'heading'",
+        "pos": 497,
+        "start": {
+            "character": 497,
+            "column": 4,
+            "line": 19
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 543,
+            "column": 18,
+            "line": 20
+        },
+        "message": "A11y: Redundant role 'heading'",
+        "pos": 529,
+        "start": {
+            "character": 529,
+            "column": 4,
+            "line": 20
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 577,
+            "column": 20,
+            "line": 21
+        },
+        "message": "A11y: Redundant role 'separator'",
+        "pos": 561,
+        "start": {
+            "character": 561,
+            "column": 4,
+            "line": 21
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 600,
+            "column": 19,
+            "line": 22
+        },
+        "message": "A11y: Redundant role 'listitem'",
+        "pos": 585,
+        "start": {
+            "character": 585,
+            "column": 4,
+            "line": 22
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 621,
+            "column": 17,
+            "line": 23
+        },
+        "message": "A11y: Redundant role 'link'",
+        "pos": 610,
+        "start": {
+            "character": 610,
+            "column": 6,
+            "line": 23
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 642,
+            "column": 17,
+            "line": 24
+        },
         "message": "A11y: Redundant role 'main'",
-        "pos": 162,
+        "pos": 631,
         "start": {
-            "character": 162,
+            "character": 631,
             "column": 6,
-            "line": 7
+            "line": 24
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 668,
+            "column": 17,
+            "line": 25
+        },
+        "message": "A11y: Redundant role 'list'",
+        "pos": 657,
+        "start": {
+            "character": 657,
+            "column": 6,
+            "line": 25
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 694,
+            "column": 22,
+            "line": 26
+        },
+        "message": "A11y: Redundant role 'navigation'",
+        "pos": 677,
+        "start": {
+            "character": 677,
+            "column": 5,
+            "line": 26
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 713,
+            "column": 15,
+            "line": 27
+        },
+        "message": "A11y: Redundant role 'list'",
+        "pos": 702,
+        "start": {
+            "character": 702,
+            "column": 4,
+            "line": 27
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 739,
+            "column": 22,
+            "line": 28
+        },
+        "message": "A11y: Redundant role 'group'",
+        "pos": 727,
+        "start": {
+            "character": 727,
+            "column": 10,
+            "line": 28
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 764,
+            "column": 21,
+            "line": 29
+        },
+        "message": "A11y: Redundant role 'option'",
+        "pos": 751,
+        "start": {
+            "character": 751,
+            "column": 8,
+            "line": 29
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 789,
+            "column": 21,
+            "line": 30
+        },
+        "message": "A11y: Redundant role 'status'",
+        "pos": 776,
+        "start": {
+            "character": 776,
+            "column": 8,
+            "line": 30
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 821,
+            "column": 28,
+            "line": 31
+        },
+        "message": "A11y: Redundant role 'progressbar'",
+        "pos": 803,
+        "start": {
+            "character": 803,
+            "column": 10,
+            "line": 31
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 847,
+            "column": 22,
+            "line": 32
+        },
+        "message": "A11y: Redundant role 'region'",
+        "pos": 834,
+        "start": {
+            "character": 834,
+            "column": 9,
+            "line": 32
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 873,
+            "column": 22,
+            "line": 33
+        },
+        "message": "A11y: Redundant role 'button'",
+        "pos": 860,
+        "start": {
+            "character": 860,
+            "column": 9,
+            "line": 33
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 896,
+            "column": 19,
+            "line": 34
+        },
+        "message": "A11y: Redundant role 'table'",
+        "pos": 884,
+        "start": {
+            "character": 884,
+            "column": 7,
+            "line": 34
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 922,
+            "column": 22,
+            "line": 35
+        },
+        "message": "A11y: Redundant role 'rowgroup'",
+        "pos": 907,
+        "start": {
+            "character": 907,
+            "column": 7,
+            "line": 35
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 950,
+            "column": 24,
+            "line": 36
+        },
+        "message": "A11y: Redundant role 'textbox'",
+        "pos": 936,
+        "start": {
+            "character": 936,
+            "column": 10,
+            "line": 36
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 976,
+            "column": 22,
+            "line": 37
+        },
+        "message": "A11y: Redundant role 'rowgroup'",
+        "pos": 961,
+        "start": {
+            "character": 961,
+            "column": 7,
+            "line": 37
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 1002,
+            "column": 22,
+            "line": 38
+        },
+        "message": "A11y: Redundant role 'rowgroup'",
+        "pos": 987,
+        "start": {
+            "character": 987,
+            "column": 7,
+            "line": 38
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 1020,
+            "column": 14,
+            "line": 39
+        },
+        "message": "A11y: Redundant role 'row'",
+        "pos": 1010,
+        "start": {
+            "character": 1010,
+            "column": 4,
+            "line": 39
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 1039,
+            "column": 15,
+            "line": 40
+        },
+        "message": "A11y: Redundant role 'list'",
+        "pos": 1028,
+        "start": {
+            "character": 1028,
+            "column": 4,
+            "line": 40
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 1125,
+            "column": 21,
+            "line": 43
+        },
+        "message": "A11y: Redundant role 'banner'",
+        "pos": 1112,
+        "start": {
+            "character": 1112,
+            "column": 8,
+            "line": 43
+        }
+    },
+    {
+        "code": "a11y-no-redundant-roles",
+        "end": {
+            "character": 1162,
+            "column": 26,
+            "line": 44
+        },
+        "message": "A11y: Redundant role 'contentinfo'",
+        "pos": 1144,
+        "start": {
+            "character": 1144,
+            "column": 8,
+            "line": 44
         }
     }
 ]
\ No newline at end of file

From 2b05e542b33bf112c0b76952a56d0f2a505c2ebe Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Fri, 31 Dec 2021 16:02:14 +0000
Subject: [PATCH 16/17] move constants to top of file and rename with a11y
 prefix

---
 src/compiler/compile/nodes/Element.ts | 85 ++++++++++++++-------------
 1 file changed, 43 insertions(+), 42 deletions(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 19e563026293..6122ba473a48 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -70,6 +70,47 @@ const a11y_labelable = new Set([
 	'textarea'
 ]);
 
+const a11y_nested_implicit_semantics = new Map([
+	['header', 'banner'],
+	['footer', 'contentinfo']
+]);
+
+const a11y_implicit_semantics = new Map([
+	['a', 'link'],
+	['article', 'article'],
+	['aside', 'complementary'],
+	['body', 'document'],
+	['datalist', 'listbox'],
+	['dd', 'definition'],
+	['dfn', 'term'],
+	['details', 'group'],
+	['dt', 'term'],
+	['fieldset', 'group'],
+	['form', 'form'],
+	['h1', 'heading'],
+	['h2', 'heading'],
+	['h3', 'heading'],
+	['h4', 'heading'],
+	['h5', 'heading'],
+	['h6', 'heading'],
+	['hr', 'separator'],
+	['li', 'listitem'],
+	['menu', 'list'],
+	['nav', 'navigation'],
+	['ol', 'list'],
+	['optgroup', 'group'],
+	['output', 'status'],
+	['progress', 'progressbar'],
+	['section', 'region'],
+	['summary', 'button'],
+	['tbody', 'rowgroup'],
+	['textarea', 'textbox'],
+	['tfoot', 'rowgroup'],
+	['thead', 'rowgroup'],
+	['tr', 'row'],
+	['ul', 'list']
+]);
+
 const invisible_elements = new Set(['meta', 'html', 'script', 'style']);
 
 const valid_modifiers = new Set([
@@ -370,56 +411,16 @@ export default class Element extends Node {
 				}
 
 				// no-redundant-roles
-				const implicit_semantics = new Map([
-					['a', 'link'],
-					['article', 'article'],
-					['aside', 'complementary'],
-					['body', 'document'],
-					['datalist', 'listbox'],
-					['dd', 'definition'],
-					['dfn', 'term'],
-					['details', 'group'],
-					['dt', 'term'],
-					['fieldset', 'group'],
-					['form', 'form'],
-					['h1', 'heading'],
-					['h2', 'heading'],
-					['h3', 'heading'],
-					['h4', 'heading'],
-					['h5', 'heading'],
-					['h6', 'heading'],
-					['hr', 'separator'],
-					['li', 'listitem'],
-					['menu', 'list'],
-					['nav', 'navigation'],
-					['ol', 'list'],
-					['optgroup', 'group'],
-					['output', 'status'],
-					['progress', 'progressbar'],
-					['section', 'region'],
-					['summary', 'button'],
-					['tbody', 'rowgroup'],
-					['textarea', 'textbox'],
-					['tfoot', 'rowgroup'],
-					['thead', 'rowgroup'],
-					['tr', 'row'],
-					['ul', 'list']
-				]);
-
-				const has_redundant_role = value === implicit_semantics.get(this.name);
+				const has_redundant_role = value === a11y_implicit_semantics.get(this.name);
 
 				if (this.name === value || has_redundant_role) {
 					component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 				}
 
 				// Footers and headers are special cases, and should not have redundant roles unless they are the children of sections or articles.
-				const nested_implicit_semantics = new Map([
-					['header', 'banner'],
-					['footer', 'contentinfo']
-				]);
 				const is_parent_section_or_article = is_parent(this.parent, ['section', 'article']);
 				if (!is_parent_section_or_article) {
-					const has_nested_redundant_role = value === nested_implicit_semantics.get(this.name);
+					const has_nested_redundant_role = value === a11y_nested_implicit_semantics.get(this.name);
 					if (has_nested_redundant_role) {
 						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}

From 6ab5c7fa6fdc0f75a5c82f89d801f80c00728284 Mon Sep 17 00:00:00 2001
From: James Bradbury <me@jamesbradbury.net>
Date: Fri, 31 Dec 2021 16:26:54 +0000
Subject: [PATCH 17/17] remove case caught by (this.name === value)

---
 src/compiler/compile/nodes/Element.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 6122ba473a48..bf81599bf6d7 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -77,7 +77,6 @@ const a11y_nested_implicit_semantics = new Map([
 
 const a11y_implicit_semantics = new Map([
 	['a', 'link'],
-	['article', 'article'],
 	['aside', 'complementary'],
 	['body', 'document'],
 	['datalist', 'listbox'],