1 files changed, 42 insertions, 0 deletions
diff --git a/js/src/tests/test262/intl402/DateTimeFormat/prototype/formatRange/fractionalSecondDigits.js b/js/src/tests/test262/intl402/DateTimeFormat/prototype/formatRange/fractionalSecondDigits.js
new file mode 100644
index 0000000000..781ea43d26
--- /dev/null
+++ b/js/src/tests/test262/intl402/DateTimeFormat/prototype/formatRange/fractionalSecondDigits.js
@@ -0,0 +1,42 @@
+// Copyright 2019 Google Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-createdatetimeformat
+description: Checks basic handling of fractionalSecondDigits.
+features: [Intl.DateTimeFormat-fractionalSecondDigits, Intl.DateTimeFormat-formatRange]
+locale: [en-US]
+---*/
+
+// Tolerate implementation variance by expecting consistency without being prescriptive.
+// TODO: can we change tests to be less reliant on CLDR formats while still testing that
+// Temporal and Intl are behaving as expected?
+const usDateRangeSeparator = new Intl.DateTimeFormat("en-US", { dateStyle: "short" })
+  .formatRangeToParts(1 * 86400 * 1000, 366 * 86400 * 1000)
+  .find((part) => part.type === "literal" && part.source === "shared").value;
+
+const d1 = new Date(2019, 7, 10,  1, 2, 3, 234);
+const d2 = new Date(2019, 7, 10,  1, 2, 3, 567);
+const d3 = new Date(2019, 7, 10,  1, 2, 13, 987);
+
+let dtf = new Intl.DateTimeFormat(
+    'en', { minute: "numeric", second: "numeric", fractionalSecondDigits: undefined});
+assert.sameValue(dtf.formatRange(d1, d2), "02:03", "no fractionalSecondDigits");
+assert.sameValue(dtf.formatRange(d1, d3), `02:03${usDateRangeSeparator}02:13`, "no fractionalSecondDigits");
+
+dtf = new Intl.DateTimeFormat(
+    'en', { minute: "numeric", second: "numeric", fractionalSecondDigits: 1});
+assert.sameValue(dtf.formatRange(d1, d2), `02:03.2${usDateRangeSeparator}02:03.5`, "1 fractionalSecondDigits round down");
+assert.sameValue(dtf.formatRange(d1, d3), `02:03.2${usDateRangeSeparator}02:13.9`, "1 fractionalSecondDigits round down");
+
+dtf = new Intl.DateTimeFormat(
+    'en', { minute: "numeric", second: "numeric", fractionalSecondDigits: 2});
+assert.sameValue(dtf.formatRange(d1, d2), `02:03.23${usDateRangeSeparator}02:03.56`, "2 fractionalSecondDigits round down");
+assert.sameValue(dtf.formatRange(d1, d3), `02:03.23${usDateRangeSeparator}02:13.98`, "2 fractionalSecondDigits round down");
+
+dtf = new Intl.DateTimeFormat(
+    'en', { minute: "numeric", second: "numeric", fractionalSecondDigits: 3});
+assert.sameValue(dtf.formatRange(d1, d2), `02:03.234${usDateRangeSeparator}02:03.567`, "3 fractionalSecondDigits round down");
+assert.sameValue(dtf.formatRange(d1, d3), `02:03.234${usDateRangeSeparator}02:13.987`, "3 fractionalSecondDigits round down");
+
+reportCompare(0, 0);