metrics: Prefer public family name to internal familyName metrics

.changeset/funny-trees-listen.md

@@ -0,0 +1,53 @@
+---
+'@capsizecss/metrics': major
+---
+
+metrics: Prefer public family name to internal `familyName` metrics
+
+Ensure metrics are available using the public family name as seen on Google Fonts as opposed to the internal family name metric.
+This makes sense as consumers are looking to import the metrics relevant to a specific system font or from Google Fonts (also aligns with the names Google use in their font declarations generated in the hosted stylesheets).
+
+### BREAKING CHANGES:
+
+#### Google Fonts
+
+Previously, the metrics were imported with a path that used the internal family name, now they align with the font as seen on Google Fonts.
+
+```diff
+-import metrics from '@capsizecss/metrics/roundedMplus1c';
++import metrics from '@capsizecss/metrics/mPLUSRounded1c';
+```
+
+With only a small number of Google Fonts affected, this is only a break for the following fonts:
+- Ballet
+- Bodoni Moda
+- Buda
+- Bungee Spice
+- Fjord One
+- Geologica
+- Imbue
+- M PLUS Rounded 1c
+- Material Symbols Outlined
+- Material Symbols Rounded
+- Material Symbols Sharp
+- Montagu Slab
+- Nanum Pen Script
+- Newsreader
+- Nunito Sans
+- Pathway Extreme
+- Sono
+- Sunflower
+- Supermercado One
+- Texturina
+
+
+#### System fonts
+
+The system fonts only had one example where the names diverged:
+
+```diff
+-import metrics from '@capsizecss/metrics/brushScriptMT';
++import metrics from '@capsizecss/metrics/brushScript';
+```
+
+This now aligns with the name consumers use to reference the font on their system.

packages/metrics/scripts/extract.ts

@@ -23,6 +23,7 @@ const extractor: Record<SourceType, typeof fromFile | typeof fromUrl> = {
 };
 
 export type FontSourceList = Array<{
+  family: string;
   variants?: string[];
   files: Record<string, string>;
   category: FontCategory;
@@ -58,17 +59,21 @@ const metricsForFamily = async ({
   });
 
   const result = await queue.addAll(
-    fonts.map(({ files, variants = [], overrides, category }) => async () => {
-      const variant = files.regular ? 'regular' : variants[0];
-      const url = files[variant];
-      const metrics = await extractor[sourceType](url);
-
-      return {
-        ...metrics,
-        ...overrides,
-        category,
-      };
-    }),
+    fonts.map(
+      ({ family, files, variants = [], overrides, category }) =>
+        async () => {
+          const variant = files.regular ? 'regular' : variants[0];
+          const url = files[variant];
+          const metrics = await extractor[sourceType](url);
+
+          return {
+            ...metrics,
+            ...overrides,
+            familyName: family,
+            category,
+          };
+        },
+    ),
   );
 
   progress.stop();