feat: add Backstage social icon (#2600)

Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

4 files changed, 9 insertions, 1 deletions

diff --git a/.changeset/soft-snails-chew.md b/.changeset/soft-snails-chew.md
new file mode 100644
index 00000000..bd3219f0
--- /dev/null
+++ b/.changeset/soft-snails-chew.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/starlight': patch
+---
+
+Adds Backstage social icon
diff --git a/packages/starlight/__tests__/basics/config-errors.test.ts b/packages/starlight/__tests__/basics/config-errors.test.ts
index bcbe08f1..6a453895 100644
--- a/packages/starlight/__tests__/basics/config-errors.test.ts
+++ b/packages/starlight/__tests__/basics/config-errors.test.ts
@@ -114,7 +114,7 @@ test('errors with bad social icon config', () => {
 		"[AstroUserError]:
 			Invalid config passed to starlight integration
 		Hint:
-			**social.unknown**: Invalid enum value. Expected 'twitter' | 'mastodon' | 'github' | 'gitlab' | 'bitbucket' | 'discord' | 'gitter' | 'codeberg' | 'codePen' | 'youtube' | 'threads' | 'linkedin' | 'twitch' | 'azureDevOps' | 'microsoftTeams' | 'instagram' | 'stackOverflow' | 'x.com' | 'telegram' | 'rss' | 'facebook' | 'email' | 'reddit' | 'patreon' | 'signal' | 'slack' | 'matrix' | 'openCollective' | 'hackerOne' | 'blueSky' | 'discourse' | 'zulip' | 'pinterest' | 'tiktok' | 'nostr', received 'unknown'
+			**social.unknown**: Invalid enum value. Expected 'twitter' | 'mastodon' | 'github' | 'gitlab' | 'bitbucket' | 'discord' | 'gitter' | 'codeberg' | 'codePen' | 'youtube' | 'threads' | 'linkedin' | 'twitch' | 'azureDevOps' | 'microsoftTeams' | 'instagram' | 'stackOverflow' | 'x.com' | 'telegram' | 'rss' | 'facebook' | 'email' | 'reddit' | 'patreon' | 'signal' | 'slack' | 'matrix' | 'openCollective' | 'hackerOne' | 'blueSky' | 'discourse' | 'zulip' | 'pinterest' | 'tiktok' | 'nostr' | 'backstage', received 'unknown'
 			**social.unknown**: Invalid url"
 	`
 	);
diff --git a/packages/starlight/components/Icons.ts b/packages/starlight/components/Icons.ts
index 96ea4e43..2fed6c22 100644
--- a/packages/starlight/components/Icons.ts
+++ b/packages/starlight/components/Icons.ts
@@ -160,6 +160,7 @@ export const BuiltInIcons = {
 	jsr: '<path d="M3.7 5.54v3.7H0v7.38h7.38v1.84h12.93v-3.7H24V7.39h-7.38V5.54Zm1.84 1.85h1.85v7.38H1.84v-3.7h1.84v1.85h1.85zm3.7 0h5.53v1.84h-3.7v1.85h3.7v5.53H9.23v-1.84h3.7v-1.85h-3.7Zm7.38 1.84h5.53v3.7h-1.84v-1.85h-1.85v5.54h-1.84z"/>',
 	nostr:
 		'<path d="M21.6 10.6v9.7a.7.7 0 0 1-.6.6h-8a.7.7 0 0 1-.6-.6v-1.8c0-2.2.3-4.4.8-5.3a2 2 0 0 1 1.3-1c1-.4 2.9-.2 3.7-.2 0 0 2.3 0 2.3-1.3 0-1-1-1-1-1-1.2 0-2 0-2.6-.2-1-.4-1-1.1-1-1.3 0-2.7-4-3-7.5-2.4-3.9.7 0 6.2 0 13.5v1a.7.7 0 0 1-.7.6H3.8a.7.7 0 0 1-.6-.6V3.5a.7.7 0 0 1 .6-.6h3.7a.7.7 0 0 1 .7.6c0 .6.6.9 1 .6 1.3-1 3-1.5 5-1.5 4.2 0 7.4 2.5 7.4 8zm-7-2a1.4 1.4 0 1 0-2.9 0 1.4 1.4 0 0 0 2.9 0z"/>',
+  backstage: '<path d="M18.4 9.3a4.4 4.4 0 0 0 .7-.5l.1-.1a4.5 4.5 0 0 0 .8-1.1l.3-1c0-1-.6-2-2-3L12.7.4 6 6.6l-4.3 4 6 3.7a6.1 6.1 0 0 0 3 .9c1.5 0 2.8-.5 3.7-1.4 1-1 1.4-2.3.8-3.4a2.8 2.8 0 0 0-.4-.5l1 .1a4.6 4.6 0 0 0 1.8-.3 4.5 4.5 0 0 0 .7-.3zm-5.5 3.3c-1 1-2.8 1.2-4.2.4l-4.1-2.5 3.7-3.6 4.2 2.6c1.5.9 1.4 2.1.4 3.1zm.5-4.5-4-2.3L13 2.4l3.8 2.3c1.4.9 1.6 2 .6 3a3.3 3.3 0 0 1-4 .4zM15 18.5c-1 1-2.5 1.6-4.1 1.6a6.8 6.8 0 0 1-3.5-1l-5.6-3.4v1.4l6 3.6a6.1 6.1 0 0 0 3 .9c1.5 0 2.8-.5 3.7-1.4.7-.7 1.1-1.5 1.1-2.3l-.6.6zm0-2.1c-1 1-2.5 1.6-4.1 1.6a6.8 6.8 0 0 1-3.5-1l-5.6-3.4V15l6 3.6a6.1 6.1 0 0 0 3 .9c1.5 0 2.8-.5 3.7-1.4.7-.7 1.1-1.5 1.1-2.3v-.1l-.6.7zm0-2.1c-1 1-2.5 1.6-4.1 1.6a6.8 6.8 0 0 1-3.5-1l-5.6-3.4v1.3l6 3.6a6.1 6.1 0 0 0 3 1c1.5 0 2.8-.6 3.7-1.5.7-.7 1.1-1.5 1.1-2.3l-.6.7zm4.6 1.4a5.2 5.2 0 0 1-3.3 1.4v1.5a4.5 4.5 0 0 0 2.8-1.3c.8-.7 1.2-1.5 1.2-2.3v-.1l-.7.8zm-4.6 5c-1 1-2.5 1.6-4.1 1.6a6.8 6.8 0 0 1-3.5-1l-5.6-3.4v1.3l6 3.6a6.1 6.1 0 0 0 3 1c1.5 0 2.8-.5 3.7-1.5.7-.6 1.1-1.5 1.1-2.2V20l-.6.7zM19.7 9l-.1.2-1.2.8a5.2 5.2 0 0 1-1.5.5 5.2 5.2 0 0 1-.8 0l.1.4V12a4.6 4.6 0 0 0 1.5-.3A4.4 4.4 0 0 0 19 11l.1-.1a4.5 4.5 0 0 0 .8-1.1 2.6 2.6 0 0 0 .3-1.1v-.1l-.2.1-.4.6zm0 4.3a6 6 0 0 1-.1.1 5.2 5.2 0 0 1-3.3 1.5v1.4a4.5 4.5 0 0 0 2.8-1.2l1-1.2.2-1v-.1l-.2.2a4.8 4.8 0 0 1-.4.5zm0-2.1-.1.1a4.8 4.8 0 0 1-.6.5 5.2 5.2 0 0 1-2.7 1v1.4A4.5 4.5 0 0 0 19 13h.1a4.2 4.2 0 0 0 .8-1.2l.3-.9v-.3a4 4 0 0 1-.2.2l-.4.5z"/>'
 };
 
 export const Icons = {
diff --git a/packages/starlight/schemas/social.ts b/packages/starlight/schemas/social.ts
index c1ecdf9f..05d5f9da 100644
--- a/packages/starlight/schemas/social.ts
+++ b/packages/starlight/schemas/social.ts
@@ -36,6 +36,7 @@ export const socialLinks = [
 	'pinterest',
 	'tiktok',
 	'nostr',
+	'backstage'
 ] as const;
 
 export const SocialLinksSchema = () =>
@@ -87,6 +88,7 @@ export const SocialLinksSchema = () =>
 					pinterest: 'Pinterest',
 					tiktok: 'TikTok',
 					nostr: 'Nostr',
+					backstage: 'Backstage'
 				}[key];
 				labelledLinks[key] = { label, url };
 			}