Normalize conversion factor formatting

tests/test_quick_conversion_formatting.py

@@ -0,0 +1,26 @@
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+QUICK_CONVERSION_EXAMPLE = (
+    ROOT / "hdyc-svelte" / "src" / "lib" / "components" / "QuickConversionExample.svelte"
+)
+
+
+class QuickConversionExampleFormattingTests(unittest.TestCase):
+    def test_formula_uses_formatted_factor_and_offset(self) -> None:
+        text = QUICK_CONVERSION_EXAMPLE.read_text(encoding="utf-8")
+        normalized = " ".join(text.split())
+        snippet = (
+            "1 {config.labels.in1} = {formattedFactorValue}{hasOffset ? ` + ${formattedOffsetValue}` : ''} "
+            "{config.labels.in2}"
+        )
+        self.assertIn(
+            snippet,
+            normalized,
+            "The formula snippet should render formatted factor/offset values instead of raw floats",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()