Bug 1662977: Allow "maximumFractionDigits" option in Intl.NumberForma…

…t to be less than the default minimum fraction digits. r=yulia

Implements the changes from the "has consensus" PR <tc39/ecma402#471>.

The second pair of `DefaultNumberOption()` calls was inlined, because only the
fallback case is relevant anyway. Steps 12.d and 12.e from the spec PR were
combined into a single `if`-block. That way it also matches step 12.f more
closely.

Also changed the single `if` steps into an `if-else if` chain, because the
steps are mutually exclusive.

Depends on D95734

Differential Revision: https://phabricator.services.mozilla.com/D95735

js/src/builtin/intl/NumberFormat.js

@@ -181,18 +181,33 @@ function SetNumberFormatDigitOptions(lazyData, options, mnfdDefault, mxfdDefault
         // Step 12.a (Omitted).
 
         // Step 12.b.
-        mnfd = DefaultNumberOption(mnfd, 0, 20, mnfdDefault);
+        mnfd = DefaultNumberOption(mnfd, 0, 20, undefined);
 
         // Step 12.c.
-        const mxfdActualDefault = std_Math_max(mnfd, mxfdDefault);
+        mxfd = DefaultNumberOption(mxfd, 0, 20, undefined);
 
-        // Step 12.d.
-        mxfd = DefaultNumberOption(mxfd, mnfd, 20, mxfdActualDefault);
+        // Steps 12.d-e.
+        // Inlined DefaultNumberOption, only the fallback case applies here.
+        if (mnfd === undefined) {
+            assert(mxfd !== undefined, "mxfd isn't undefined when mnfd is undefined");
+            mnfd = std_Math_min(mnfdDefault, mxfd);
+        }
 
-        // Step 12.e.
+        // Step 12.f.
+        // Inlined DefaultNumberOption, only the fallback case applies here.
+        else if (mxfd === undefined) {
+            mxfd = std_Math_max(mxfdDefault, mnfd);
+        }
+
+        // Step 12.g.
+        else if (mnfd > mxfd) {
+            ThrowRangeError(JSMSG_INVALID_DIGITS_VALUE, mxfd);
+        }
+
+        // Step 12.h.
         lazyData.minimumFractionDigits = mnfd;
 
-        // Step 12.f.
+        // Step 12.i.
         lazyData.maximumFractionDigits = mxfd;
     }
 

js/src/tests/jstests.list

@@ -282,9 +282,6 @@ skip script test262/language/expressions/compound-assignment/compound-assignment
 skip script test262/language/expressions/compound-assignment/compound-assignment-operator-calls-putvalue-lref--v-.js
 skip script test262/language/expressions/compound-assignment/compound-assignment-operator-calls-putvalue-lref--v--20.js
 
-# https://bugzilla.mozilla.org/show_bug.cgi?id=1662977
-skip script test262/intl402/NumberFormat/dft-currency-mnfd-range-check-mxfd.js
-
 # https://bugzilla.mozilla.org/show_bug.cgi?id=1670502
 skip script test262/built-ins/Function/prototype/toString/built-in-function-object.js