From 9d7094b72362d61bfa13e5b60929df80d05ec204 Mon Sep 17 00:00:00 2001
From: Chris <151883835+VeronicDev@users.noreply.github.com>
Date: Thu, 22 Oct 2026 12:12:25 +0100
Subject: [PATCH] Fix #1780: [test] Cover amount parser locale and exponent
 inputs

---
 frontend/src/utils/amount.test.ts | 72 +++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 frontend/src/utils/amount.test.ts

diff --git a/frontend/src/utils/amount.test.ts b/frontend/src/utils/amount.test.ts
new file mode 100644
index 00000000..a7b0165f
--- /dev/null
+++ b/frontend/src/utils/amount.test.ts
@@ -0,0 +1,72 @@
+import { describe, it, expect } from "vitest";
+import {
+  parseAmount,
+  formatAmount,
+  validateAmountInput,
+  hasValidPrecision,
+} from "./amount";
+
+describe("amount parser locale, exponent, whitespace, and empty strings", () => {
+  describe("parseAmount with locale and edge inputs", () => {
+    it("handles empty and whitespace-only strings", () => {
+      expect(parseAmount("", 7)).toBe(0n);
+      expect(parseAmount("   ", 7)).toBe(0n);
+      expect(parseAmount("\t\n", 7)).toBe(0n);
+    });
+
+    it("rejects or handles exponent notation correctly", () => {
+      // Exponent notation like '1e5' is non-standard for strict decimal input parsers unless handled,
+      // parseAmount regex /^[\d]*\.?[\d]*$/ rejects 'e'. Verify it returns 0n.
+      expect(parseAmount("1e5", 7)).toBe(0n);
+      expect(parseAmount("1.5E-2", 7)).toBe(0n);
+    });
+
+    it("handles locale separators (comma vs dot) and invalid punctuation", () => {
+      // parseAmount expects dot (.) as decimal separator. Commas should be treated as non-digits / invalid formats.
+      expect(parseAmount("1,234", 7)).toBe(0n);
+      expect(parseAmount("1.234.56", 7)).toBe(0n);
+    });
+
+    it("handles leading and trailing whitespace around valid numbers", () => {
+      expect(parseAmount("  123.45  ", 7)).toBe(1234500000n);
+      expect(parseAmount("\t0.1\n", 7)).toBe(1000000n);
+    });
+  });
+
+  describe("validateAmountInput with exponent and locale inputs", () => {
+    it("rejects exponent notation with valid error message", () => {
+      expect(validateAmountInput("1e5", 7)).toBe("Please enter a valid number");
+      expect(validateAmountInput("1.2e-3", 7)).toBe("Please enter a valid number");
+    });
+
+    it("rejects locale comma separators", () => {
+      expect(validateAmountInput("1,234.56", 7)).toBe("Please enter a valid number");
+      expect(validateAmountInput("1,5", 7)).toBe("Please enter a valid number");
+    });
+
+    it("validates whitespace and empty strings", () => {
+      expect(validateAmountInput("", 7)).toBe("Amount is required");
+      expect(validateAmountInput("   ", 7)).toBe("Amount is required");
+      expect(validateAmountInput("0", 7)).toBe("Amount must be greater than 0");
+    });
+  });
+
+  describe("formatAmount and edge cases", () => {
+    it("formats zero and boundary bigints correctly", () => {
+      expect(formatAmount(0n, 7)).toBe("0");
+      expect(formatAmount(1n, 7)).toBe("0.0000001");
+      expect(formatAmount(10000000n, 7)).toBe("1");
+    });
+  });
+
+  describe("hasValidPrecision with exponents and edge cases", () => {
+    it("handles empty and whitespace correctly", () => {
+      expect(hasValidPrecision("", 7)).toBe(true);
+      expect(hasValidPrecision("   ", 7)).toBe(true);
+    });
+
+    it("rejects exponential notation in precision check", () => {
+      expect(hasValidPrecision("1e-5", 7)).toBe(false);
+    });
+  });
+});