1 files changed, 132 insertions, 0 deletions
diff --git a/js/src/tests/non262/Intl/NumberFormat/rounding-priority.js b/js/src/tests/non262/Intl/NumberFormat/rounding-priority.js
new file mode 100644
index 0000000000..49c9e1b274
--- /dev/null
+++ b/js/src/tests/non262/Intl/NumberFormat/rounding-priority.js
@@ -0,0 +1,132 @@
+// |reftest| skip-if(!this.hasOwnProperty("Intl")||release_or_beta)
+
+const tests = [
+  // Rounding conflict with maximum fraction/significand digits.
+  {
+    value: 4.321,
+    options: {
+      maximumFractionDigits: 2,
+      maximumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "4.3",
+      lessPrecision: "4.3",
+      morePrecision: "4.32",
+    },
+  },
+  {
+    value: 4.321,
+    options: {
+      maximumFractionDigits: 2,
+      minimumFractionDigits: 2,
+      maximumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "4.3",
+      lessPrecision: "4.3",
+      morePrecision: "4.32",
+    },
+  },
+  {
+    value: 4.321,
+    options: {
+      maximumFractionDigits: 2,
+      maximumSignificantDigits: 2,
+      minimumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "4.3",
+      lessPrecision: "4.3",
+      morePrecision: "4.32",
+    },
+  },
+  {
+    value: 4.321,
+    options: {
+      maximumFractionDigits: 2,
+      minimumFractionDigits: 2,
+      maximumSignificantDigits: 2,
+      minimumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "4.3",
+      lessPrecision: "4.3",
+      morePrecision: "4.32",
+    },
+  },
+
+  // Rounding conflict with minimum fraction/significand digits.
+  {
+    value: 1.0,
+    options: {
+      minimumFractionDigits: 2,
+      minimumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "1.0",
+      // Returning "1.00" for both options seems unexpected. Also filed at
+      // <https://github.com/tc39/proposal-intl-numberformat-v3/issues/52>.
+      lessPrecision: "1.00",
+      morePrecision: "1.0",
+    },
+  },
+  {
+    value: 1.0,
+    options: {
+      minimumFractionDigits: 2,
+      maximumFractionDigits: 2,
+      minimumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "1.0",
+      lessPrecision: "1.00",
+      morePrecision: "1.0",
+    },
+  },
+  {
+    value: 1.0,
+    options: {
+      minimumFractionDigits: 2,
+      minimumSignificantDigits: 2,
+      maximumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "1.0",
+      lessPrecision: "1.0",
+      morePrecision: "1.00",
+    },
+  },
+  {
+    value: 1.0,
+    options: {
+      minimumFractionDigits: 2,
+      maximumFractionDigits: 2,
+      minimumSignificantDigits: 2,
+      maximumSignificantDigits: 2,
+    },
+    roundingPriorities: {
+      auto: "1.0",
+      lessPrecision: "1.0",
+      morePrecision: "1.00",
+    },
+  },
+];
+
+for (let {value, options, roundingPriorities} of tests) {
+  for (let [roundingPriority, expected] of Object.entries(roundingPriorities)) {
+    let nf = new Intl.NumberFormat("en", {...options, roundingPriority});
+    assertEq(nf.resolvedOptions().roundingPriority, roundingPriority);
+    assertEq(nf.format(value), expected, `value=${value}, roundingPriority=${roundingPriority}`);
+  }
+}
+
+// Default value of "auto".
+assertEq(new Intl.NumberFormat().resolvedOptions().roundingPriority, "auto");
+
+// Invalid values.
+for (let roundingPriority of ["", null, "more", "less", "never"]){
+  assertThrowsInstanceOf(() => new Intl.NumberFormat("en", {roundingPriority}), RangeError);
+}
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);