fix(utils): allow integer prices written with trailing decimal zeros in formatPrice

src/utils/_format.ts

@@ -29,6 +29,14 @@ export function formatPrice(price: string | number, szDecimals: number, type: "p
   const maxDecimals = Math.max((type === "perp" ? 6 : 8) - szDecimals, 0);
   price = StringMath.toFixedTruncate(price, maxDecimals);
 
+  // Integer prices are always allowed, including values that become integers
+  // after decimal truncation (e.g. "100001.0" -> "100001"). Without this
+  // re-check the significant-figure step below would truncate them (-> "100000").
+  // A value that truncated all the way to zero is left for the zero check below.
+  if (/^-?\d+$/.test(price) && !/^-?0+$/.test(price)) {
+    return formatDecimalString(price);
+  }
+
   // Apply sig figs limit: max 5 significant figures
   price = StringMath.toPrecisionTruncate(price, 5);
 

tests/utils/format.test.ts

@@ -32,6 +32,14 @@ Deno.test("formatPrice", async (t) => {
       assertEquals(formatPrice("1234567", 0), "1234567");
     });
 
+    await t.step("integer value with trailing decimal zeros bypasses limit", () => {
+      assertEquals(formatPrice("100001.0", 0), "100001");
+      assertEquals(formatPrice("123456.0", 0), "123456");
+      assertEquals(formatPrice("100001.00", 0), "100001");
+      assertEquals(formatPrice("-123456.0", 0), "-123456");
+      assertEquals(formatPrice("100001.0", 0, "spot"), "100001");
+    });
+
     await t.step("truncates to 5 sig figs", () => {
       assertEquals(formatPrice("12345.6", 0), "12345");
       assertEquals(formatPrice("0.00123456", 0), "0.001234");