taler-typescript-core

commit d0775fae165d66ed22f21a688b00a4d62508022c
parent b0afe06ff68bf2f9a16ddbdd70bd96a97bd0d0cd
Author: Florian Dold <dold@taler.net>
Date:   Tue, 21 Jul 2026 11:04:47 +0200

util: test currency checking in sub and normalization in divide

Diffstat:
M
packages/taler-util/src/amounts.test.ts
 | 
77
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----

1 file changed, 72 insertions(+), 5 deletions(-)
diff --git a/packages/taler-util/src/amounts.test.ts b/packages/taler-util/src/amounts.test.ts
@@ -20,6 +20,7 @@ import assert from "node:assert";
 import {
   Amounts,
   AmountJson,
+  AmountLike,
   amountMaxValue,
   amountFractionalBase,
   codecForAmountJson,
@@ -316,10 +317,26 @@ test("currency validation runs on the raw string, before case folding", (t) => {
 
 test("parse and parseWithError agree", (t) => {
   const corpus = [
-    "EUR:1", "eur:1", "EUR:0.99999999", "EUR:1.999999999", "E:1", "EURO:1",
-    "ABCDEFGHIJK:1", "ABCDEFGHIJKL:1", ":1", "EUR:", "EUR:x", "EUR:1.",
-    "EU R:1", "EU-R:1", "ſ:5", "fi:5", "EüR:1", "EUR:-1",
-    "EUR:9007199254740993", "EUR:4503599627370496",
+    "EUR:1",
+    "eur:1",
+    "EUR:0.99999999",
+    "EUR:1.999999999",
+    "E:1",
+    "EURO:1",
+    "ABCDEFGHIJK:1",
+    "ABCDEFGHIJKL:1",
+    ":1",
+    "EUR:",
+    "EUR:x",
+    "EUR:1.",
+    "EU R:1",
+    "EU-R:1",
+    "ſ:5",
+    "fi:5",
+    "EüR:1",
+    "EUR:-1",
+    "EUR:9007199254740993",
+    "EUR:4503599627370496",
   ];
   for (const s of corpus) {
     const viaParse = Amounts.parse(s);
@@ -338,7 +355,13 @@ test("parse and parseWithError agree", (t) => {
 });
 
 test("amount objects are rejected when the currency is not a currency", (t) => {
-  for (const currency of ["", "not a currency €", "EUR1", "ABCDEFGHIJKL", "ſ"]) {
+  for (const currency of [
+    "",
+    "not a currency €",
+    "EUR1",
+    "ABCDEFGHIJKL",
+    "ſ",
+  ]) {
     assert.throws(
       () => Amounts.parseOrThrow({ currency, value: 1, fraction: 0 }),
       `parseOrThrow should reject currency ${JSON.stringify(currency)}`,
@@ -416,3 +439,47 @@ test("arithmetic still accepts denormalized amounts", (t) => {
     "EUR:2" as AmountString,
   );
 });
+
+test("subtraction validates all currencies before subtracting", (t) => {
+  // add() checks every operand's currency up front.  sub() returning early on
+  // underflow made the check depend on argument order, so the same multiset
+  // of operands either threw or produced a plausible saturated result.
+  assert.throws(() =>
+    Amounts.sub(
+      "EUR:1" as AmountString,
+      "EUR:2" as AmountString,
+      "USD:1" as AmountString,
+    ),
+  );
+  assert.throws(() =>
+    Amounts.sub(
+      "EUR:1" as AmountString,
+      "USD:1" as AmountString,
+      "EUR:2" as AmountString,
+    ),
+  );
+});
+
+test("division normalizes and validates its dividend", (t) => {
+  // Widened here so the file compiles before divide accepts an AmountLike.
+  const divide = Amounts.divide as (a: AmountLike, n: number) => AmountJson;
+  // Every other arithmetic entry point goes through jsonifyAmount.
+  assert.deepStrictEqual(
+    divide("EUR:10" as AmountString, 2),
+    Amounts.parseOrThrow("EUR:5"),
+  );
+  // A denormalized dividend must not yield fraction === amountFractionalBase,
+  // which the library's own parser then rejects.
+  const denormalized = { value: 0, fraction: 200000000, currency: "EUR" };
+  assert.deepStrictEqual(divide(denormalized, 2), {
+    currency: "EUR",
+    value: 1,
+    fraction: 0,
+  });
+  assert.deepStrictEqual(divide(denormalized, 1), {
+    currency: "EUR",
+    value: 2,
+    fraction: 0,
+  });
+  assert.throws(() => divide({ value: -5, fraction: 0, currency: "EUR" }, 2));
+});