Add `<Badge>` component (#1530)

Co-authored-by: HiDeoo <494699+HiDeoo@users.noreply.github.com>
Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>
Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>
Co-authored-by: trueberryless <99918022+trueberryless@users.noreply.github.com>
Co-authored-by: Martin Trapp <94928215+martrapp@users.noreply.github.com>

10 files changed, 206 insertions, 104 deletions

diff --git a/.changeset/wicked-melons-study.md b/.changeset/wicked-melons-study.md
new file mode 100644
index 00000000..9de08e60
--- /dev/null
+++ b/.changeset/wicked-melons-study.md
@@ -0,0 +1,6 @@
+---
+'@astrojs/starlight': minor
+---
+
+Adds a new `<Badge>` component
+
diff --git a/docs/src/content/docs/guides/components.mdx b/docs/src/content/docs/guides/components.mdx
index 30178aec..95a5e30f 100644
--- a/docs/src/content/docs/guides/components.mdx
+++ b/docs/src/content/docs/guides/components.mdx
@@ -412,6 +412,36 @@ import { Steps } from '@astrojs/starlight/components';
 
 </Steps>
 
+### Badges
+
+import { Badge } from '@astrojs/starlight/components';
+
+Use the `<Badge>` component to display small pieces of information, such as status or labels.
+
+Pass the content you want to display to the `text` attribute of the `<Badge>` component.
+
+By default, the badge will use the theme accent color of your site. To use a built-in badge color, set the `variant` attribute to one of the following values: `note` (blue), `tip` (purple), `danger` (red), `caution` (orange), or `success` (green).
+
+The `size` attribute (default: `small`) controls the size of the badge text. `medium` and `large` are also available options for displaying a larger badge.
+
+For further customization, use other `<span>` attributes such as `class` or `style` with custom CSS.
+
+```mdx title="src/content/docs/example.mdx"
+import { Badge } from '@astrojs/starlight/components';
+
+<Badge text="New" variant="tip" size="small" />
+<Badge text="Deprecated" variant="caution" size="medium" />
+<Badge text="Starlight" variant="note" size="large" />
+<Badge text="Custom" variant="success" style={{ fontStyle: 'italic' }} />
+```
+
+The code above generates the following on the page:
+
+<Badge text="New" variant="tip" size="small" />
+<Badge text="Deprecated" variant="caution" size="medium" />
+<Badge text="Starlight" variant="note" size="large" />
+<Badge text="Custom" variant="success" style={{ fontStyle: 'italic' }} />
+
 ### Icon
 
 import { Icon } from '@astrojs/starlight/components';
diff --git a/docs/src/content/docs/guides/sidebar.mdx b/docs/src/content/docs/guides/sidebar.mdx
index bf9d3605..0632b537 100644
--- a/docs/src/content/docs/guides/sidebar.mdx
+++ b/docs/src/content/docs/guides/sidebar.mdx
@@ -294,12 +294,14 @@ The configuration above generates the following sidebar:
 	]}
 />
 
-### Badge variants
+### Badge variants and custom styling
 
-Customize the badge styling using an object with `text` and `variant` properties.
+Customize the badge styling using an object with `text`, `variant`, and `class` properties.
 
 The `text` represents the content to display (e.g. "New").
-Override the `default` styling, which uses the accent color of your site, by setting the `variant` property to one of the following values: `note`, `tip`, `danger`, `caution` or `success`.
+By default, the badge will use the accent color of your site. To use a built-in badge style, set the `variant` property to one of the following values: `note`, `tip`, `danger`, `caution` or `success`.
+
+Optionally, you can create a custom badge style by setting the `class` property to a CSS class name.
 
 ```js {10}
 starlight({
diff --git a/docs/src/content/docs/reference/configuration.mdx b/docs/src/content/docs/reference/configuration.mdx
index a940a844..59816e1a 100644
--- a/docs/src/content/docs/reference/configuration.mdx
+++ b/docs/src/content/docs/reference/configuration.mdx
@@ -214,7 +214,8 @@ type SidebarItem = {
 ```ts
 interface BadgeConfig {
 	text: string;
-	variant: 'note' | 'tip' | 'caution' | 'danger' | 'success' | 'default';
+	variant?: 'note' | 'tip' | 'caution' | 'danger' | 'success' | 'default';
+	class?: string;
 }
 ```
 
diff --git a/docs/src/content/docs/reference/frontmatter.md b/docs/src/content/docs/reference/frontmatter.md
index 32ae46ca..41fc4a5b 100644
--- a/docs/src/content/docs/reference/frontmatter.md
+++ b/docs/src/content/docs/reference/frontmatter.md
@@ -355,7 +355,7 @@ sidebar:
 
 Add a badge to the page in the sidebar when displayed in an autogenerated group of links.
 When using a string, the badge will be displayed with a default accent color.
-Optionally, pass a [`BadgeConfig` object](/reference/configuration/#badgeconfig) with `text` and `variant` fields to customize the badge.
+Optionally, pass a [`BadgeConfig` object](/reference/configuration/#badgeconfig) with `text`, `variant`, and `class` fields to customize the badge.
 
 ```md
 ---
diff --git a/packages/starlight/components.ts b/packages/starlight/components.ts
index e564b62b..2935e9ff 100644
--- a/packages/starlight/components.ts
+++ b/packages/starlight/components.ts
@@ -1,4 +1,5 @@
 export { default as Aside } from './user-components/Aside.astro';
+export { default as Badge } from './user-components/Badge.astro';
 export { default as Card } from './user-components/Card.astro';
 export { default as CardGrid } from './user-components/CardGrid.astro';
 export { default as Icon } from './user-components/Icon.astro';
diff --git a/packages/starlight/components/Badge.astro b/packages/starlight/components/Badge.astro
deleted file mode 100644
index 7e8c0da2..00000000
--- a/packages/starlight/components/Badge.astro
+++ /dev/null
@@ -1,87 +0,0 @@
----
-import type { Badge } from '../schemas/badge';
-
-interface Props {
-	variant?: Badge['variant'] | 'outline';
-	text?: string;
-}
-const { variant = 'default', text } = Astro.props;
----
-
-<span class:list={['sl-badge', variant]} set:html={text} />
-
-<style>
-	.sl-badge {
-		display: inline-block;
-		border: 1px solid var(--sl-color-border-badge);
-		border-radius: 0.25rem;
-		font-family: var(--sl-font-system-mono);
-		font-size: var(--sl-text-xs);
-		font-weight: 400;
-		padding: 0.125rem 0.375rem;
-		line-height: 1;
-		color: #fff;
-		background-color: var(--sl-color-bg-badge);
-		overflow-wrap: anywhere;
-	}
-
-	.outline {
-		--sl-color-bg-badge: transparent;
-		--sl-color-border-badge: currentColor;
-		color: inherit;
-	}
-
-	.default {
-		--sl-color-bg-badge: var(--sl-color-accent-low);
-		--sl-color-border-badge: var(--sl-color-accent);
-	}
-
-	.note {
-		--sl-color-bg-badge: var(--sl-color-blue-low);
-		--sl-color-border-badge: var(--sl-color-blue);
-	}
-
-	.danger {
-		--sl-color-bg-badge: var(--sl-color-red-low);
-		--sl-color-border-badge: var(--sl-color-red);
-	}
-
-	.success {
-		--sl-color-bg-badge: var(--sl-color-green-low);
-		--sl-color-border-badge: var(--sl-color-green);
-	}
-
-	.caution {
-		--sl-color-bg-badge: var(--sl-color-orange-low);
-		--sl-color-border-badge: var(--sl-color-orange);
-	}
-
-	.tip {
-		--sl-color-bg-badge: var(--sl-color-purple-low);
-		--sl-color-border-badge: var(--sl-color-purple);
-	}
-
-	:global([data-theme='light']) .default {
-		--sl-color-bg-badge: var(--sl-color-accent-high);
-	}
-
-	:global([data-theme='light']) .note {
-		--sl-color-bg-badge: var(--sl-color-blue-high);
-	}
-
-	:global([data-theme='light']) .danger {
-		--sl-color-bg-badge: var(--sl-color-red-high);
-	}
-
-	:global([data-theme='light']) .success {
-		--sl-color-bg-badge: var(--sl-color-green-high);
-	}
-
-	:global([data-theme='light']) .caution {
-		--sl-color-bg-badge: var(--sl-color-orange-high);
-	}
-
-	:global([data-theme='light']) .tip {
-		--sl-color-bg-badge: var(--sl-color-purple-high);
-	}
-</style>
diff --git a/packages/starlight/components/SidebarSublist.astro b/packages/starlight/components/SidebarSublist.astro
index 399d191f..23252501 100644
--- a/packages/starlight/components/SidebarSublist.astro
+++ b/packages/starlight/components/SidebarSublist.astro
@@ -1,7 +1,7 @@
 ---
 import { flattenSidebar, type SidebarEntry } from '../utils/navigation';
 import Icon from '../user-components/Icon.astro';
-import Badge from './Badge.astro';
+import Badge from '../user-components/Badge.astro';
 
 interface Props {
 	sublist: SidebarEntry[];
@@ -24,13 +24,11 @@ const { sublist, nested } = Astro.props;
 					>
 						<span>{entry.label}</span>
 						{entry.badge && (
-							<>
-								{' '}
-								<Badge
-									text={entry.badge.text}
-									variant={entry.isCurrent ? 'outline' : entry.badge.variant}
-								/>
-							</>
+							<Badge
+								variant={entry.badge.variant}
+								class={entry.badge.class}
+								text={entry.badge.text}
+							/>
 						)}
 					</a>
 				) : (
@@ -41,10 +39,11 @@ const { sublist, nested } = Astro.props;
 							<div class="group-label">
 								<span class="large">{entry.label}</span>
 								{entry.badge && (
-									<>
-										{' '}
-										<Badge text={entry.badge.text} variant={entry.badge.variant} />
-									</>
+									<Badge
+										variant={entry.badge.variant}
+										class={entry.badge.class}
+										text={entry.badge.text}
+									/>
 								)}
 							</div>
 							<Icon name="right-caret" class="caret" size="1.25rem" />
diff --git a/packages/starlight/schemas/badge.ts b/packages/starlight/schemas/badge.ts
index dc6fdb67..a2cac1b1 100644
--- a/packages/starlight/schemas/badge.ts
+++ b/packages/starlight/schemas/badge.ts
@@ -4,8 +4,17 @@ const badgeSchema = () =>
 	z.object({
 		variant: z.enum(['note', 'danger', 'success', 'caution', 'tip', 'default']).default('default'),
 		text: z.string(),
+		class: z.string().optional(),
 	});
 
+export const BadgeComponentSchema = badgeSchema()
+	.extend({
+		size: z.enum(['small', 'medium', 'large']).default('small'),
+	})
+	.passthrough();
+
+export type BadgeComponentProps = z.input<typeof BadgeComponentSchema>;
+
 export const BadgeConfigSchema = () =>
 	z
 		.union([z.string(), badgeSchema()])
diff --git a/packages/starlight/user-components/Badge.astro b/packages/starlight/user-components/Badge.astro
new file mode 100644
index 00000000..821cd0a3
--- /dev/null
+++ b/packages/starlight/user-components/Badge.astro
@@ -0,0 +1,141 @@
+---
+import { BadgeComponentSchema, type BadgeComponentProps } from '../schemas/badge';
+import { parseWithFriendlyErrors } from '../utils/error-map';
+import type { HTMLAttributes } from 'astro/types';
+
+type Props = BadgeComponentProps & HTMLAttributes<'span'>;
+
+const {
+	text,
+	variant,
+	size,
+	class: customClass,
+	...attrs
+} = parseWithFriendlyErrors(
+	BadgeComponentSchema,
+	Astro.props,
+	'Invalid prop passed to the `<Badge/>` component.'
+);
+---
+
+<span class:list={['sl-badge', variant, size, customClass]} {...attrs}>{text}</span>
+
+<style>
+	:global(:root) {
+		--sl-badge-default-border: var(--sl-color-accent);
+		--sl-badge-default-bg: var(--sl-color-accent-low);
+		--sl-badge-default-text: #fff;
+
+		--sl-badge-note-border: var(--sl-color-blue);
+		--sl-badge-note-bg: var(--sl-color-blue-low);
+		--sl-badge-note-text: #fff;
+
+		--sl-badge-danger-border: var(--sl-color-red);
+		--sl-badge-danger-bg: var(--sl-color-red-low);
+		--sl-badge-danger-text: #fff;
+
+		--sl-badge-success-border: var(--sl-color-green);
+		--sl-badge-success-bg: var(--sl-color-green-low);
+		--sl-badge-success-text: #fff;
+
+		--sl-badge-caution-border: var(--sl-color-orange);
+		--sl-badge-caution-bg: var(--sl-color-orange-low);
+		--sl-badge-caution-text: #fff;
+
+		--sl-badge-tip-border: var(--sl-color-purple);
+		--sl-badge-tip-bg: var(--sl-color-purple-low);
+		--sl-badge-tip-text: #fff;
+	}
+
+	:global([data-theme='light']:root) {
+		--sl-badge-default-bg: var(--sl-color-accent-high);
+		--sl-badge-note-bg: var(--sl-color-blue-high);
+		--sl-badge-danger-bg: var(--sl-color-red-high);
+		--sl-badge-success-bg: var(--sl-color-green-high);
+		--sl-badge-caution-bg: var(--sl-color-orange-high);
+		--sl-badge-tip-bg: var(--sl-color-purple-high);
+	}
+
+	.sl-badge {
+		display: inline-block;
+		border: 1px solid var(--sl-color-border-badge);
+		border-radius: 0.25rem;
+		font-family: var(--sl-font-system-mono);
+		line-height: normal;
+		color: var(--sl-color-text-badge);
+		background-color: var(--sl-color-bg-badge);
+		overflow-wrap: anywhere;
+	}
+
+	/* Sidebar overrides */
+	:global(.sidebar-content) .sl-badge {
+		line-height: 1;
+		font-size: var(--sl-text-xs);
+		padding: 0.125rem 0.375rem;
+	}
+
+	/* outline variant */
+	:global(.sidebar-content a[aria-current='page']) > .sl-badge {
+		--sl-color-bg-badge: transparent;
+		--sl-color-border-badge: currentColor;
+		color: inherit;
+	}
+
+	/* Color variants */
+	.default {
+		--sl-color-bg-badge: var(--sl-badge-default-bg);
+		--sl-color-border-badge: var(--sl-badge-default-border);
+		--sl-color-text-badge: var(--sl-badge-default-text);
+	}
+
+	.note {
+		--sl-color-bg-badge: var(--sl-badge-note-bg);
+		--sl-color-border-badge: var(--sl-badge-note-border);
+		--sl-color-text-badge: var(--sl-badge-note-text);
+	}
+
+	.danger {
+		--sl-color-bg-badge: var(--sl-badge-danger-bg);
+		--sl-color-border-badge: var(--sl-badge-danger-border);
+		--sl-color-text-badge: var(--sl-badge-danger-text);
+	}
+
+	.success {
+		--sl-color-bg-badge: var(--sl-badge-success-bg);
+		--sl-color-border-badge: var(--sl-badge-success-border);
+		--sl-color-text-badge: var(--sl-badge-success-text);
+	}
+
+	.tip {
+		--sl-color-bg-badge: var(--sl-badge-tip-bg);
+		--sl-color-border-badge: var(--sl-badge-tip-border);
+		--sl-color-text-badge: var(--sl-badge-tip-text);
+	}
+
+	.caution {
+		--sl-color-bg-badge: var(--sl-badge-caution-bg);
+		--sl-color-border-badge: var(--sl-badge-caution-border);
+		--sl-color-text-badge: var(--sl-badge-caution-text);
+	}
+
+	/* Size variants */
+	.small {
+		font-size: var(--sl-text-xs);
+		padding: 0.125rem 0.25rem;
+	}
+
+	.medium {
+		font-size: var(--sl-text-sm);
+		padding: 0.175rem 0.35rem;
+	}
+
+	.large {
+		font-size: var(--sl-text-base);
+		padding: 0.225rem 0.45rem;
+	}
+
+	/* Badge in headings */
+	:global(.sl-markdown-content :is(h1, h2, h3, h4, h5, h6)) .sl-badge {
+		vertical-align: middle;
+	}
+</style>