fix(linter): keep YAML numeric lineHeight as a unitless multiplier

packages/cli/src/linter/model/handler.test.ts

@@ -465,6 +465,18 @@ describe('ModelHandler', () => {
       expect(result.findings[0]!.severity).toBe('error');
     });
 
+    it('keeps unquoted YAML numeric lineHeight as a unitless multiplier', () => {
+      const result = handler.execute(makeParsed({
+        typography: {
+          'body-md': { fontFamily: 'Inter', fontSize: '16px', fontWeight: 400, lineHeight: 1.6 },
+        },
+      }));
+      const body = result.designSystem.typography.get('body-md');
+      expect(body?.lineHeight?.value).toBe(1.6);
+      expect(body?.lineHeight?.unit).toBe('');
+      expect(result.findings.filter((f) => f.path?.includes('lineHeight') === true)).toHaveLength(0);
+    });
+
     it('accepts string representations of numbers for fontWeight', () => {
       const result = handler.execute(makeParsed({
         typography: {

packages/cli/src/linter/model/handler.ts

@@ -377,6 +377,25 @@ function parseTypography(props: Record<string, string | number>, path: string, f
   const dimensionProps = ['fontSize', 'lineHeight', 'letterSpacing'] as const;
   for (const prop of dimensionProps) {
     const raw = props[prop];
+    if (typeof raw === 'number' && Number.isFinite(raw)) {
+      // YAML parses unquoted unitless values as numbers. lineHeight is a
+      // unitless multiplier in both DESIGN.md and DTCG; other dimension
+      // properties still require an explicit unit.
+      if (prop === 'lineHeight') {
+        result[prop] = {
+          type: 'dimension',
+          value: raw,
+          unit: '',
+        };
+      } else {
+        findings.push({
+          severity: 'error',
+          path: `${path}.${prop}`,
+          message: `'${raw}' is not a valid dimension. Include a unit (px, rem, or em).`,
+        });
+      }
+      continue;
+    }
     if (typeof raw === 'string') {
       if (isParseableDimension(raw)) {
         const parsed = parseDimension(raw);