(@fluent/bundle) Allow only some formatting options to NUMBER and DATETIME (#464)

Author: stasm

fluent-bundle/src/builtins.ts

@@ -18,14 +18,30 @@ import {
   FluentDateTime
 } from "./types.js";
 
-function values(opts: Record<string, FluentValue>): Record<string, unknown> {
-  const unwrapped: Record<string, unknown> = {};
+function values(
+  opts: Record<string, FluentValue>,
+  allowed: Array<string>
+): Record<string, unknown> {
+  const unwrapped: Record<string, unknown> = Object.create(null);
   for (const [name, opt] of Object.entries(opts)) {
-    unwrapped[name] = opt.valueOf();
+    if (allowed.includes(name)) {
+      unwrapped[name] = opt.valueOf();
+    }
   }
   return unwrapped;
 }
 
+const NUMBER_ALLOWED = [
+  "unitDisplay",
+  "currencyDisplay",
+  "useGrouping",
+  "minimumIntegerDigits",
+  "minimumFractionDigits",
+  "maximumFractionDigits",
+  "minimumSignificantDigits",
+  "maximumSignificantDigits",
+];
+
 export function NUMBER(
   args: Array<FluentValue>,
   opts: Record<string, FluentValue>
@@ -37,12 +53,32 @@ export function NUMBER(
   }
 
   if (arg instanceof FluentNumber || arg instanceof FluentDateTime) {
-    return new FluentNumber(arg.valueOf(), { ...arg.opts, ...values(opts) });
+    return new FluentNumber(arg.valueOf(), {
+      ...arg.opts,
+      ...values(opts, NUMBER_ALLOWED)
+    });
   }
 
   throw new TypeError("Invalid argument to NUMBER");
 }
 
+const DATETIME_ALLOWED = [
+  "dateStyle",
+  "timeStyle",
+  "fractionalSecondDigits",
+  "dayPeriod",
+  "hour12",
+  "weekday",
+  "era",
+  "year",
+  "month",
+  "day",
+  "hour",
+  "minute",
+  "second",
+  "timeZoneName",
+];
+
 export function DATETIME(
   args: Array<FluentValue>,
   opts: Record<string, FluentValue>
@@ -54,7 +90,10 @@ export function DATETIME(
   }
 
   if (arg instanceof FluentNumber || arg instanceof FluentDateTime) {
-    return new FluentDateTime(arg.valueOf(), { ...arg.opts, ...values(opts) });
+    return new FluentDateTime(arg.valueOf(), {
+      ...arg.opts,
+      ...values(opts, DATETIME_ALLOWED)
+    });
   }
 
   throw new TypeError("Invalid argument to DATETIME");

fluent-bundle/test/arguments_test.js

@@ -5,7 +5,7 @@ import ftl from "@fluent/dedent";
 
 import {FluentBundle} from '../esm/bundle';
 import {FluentResource} from '../esm/resource';
-import {FluentType} from '../esm/types';
+import {FluentType, FluentNumber, FluentDateTime} from '../esm/types';
 
 suite('Variables', function() {
   let bundle, errs;
@@ -171,45 +171,54 @@ suite('Variables', function() {
   });
 
   suite('and numbers', function(){
-    let args;
-
     suiteSetup(function() {
       bundle = new FluentBundle('en-US', { useIsolating: false });
       bundle.addResource(new FluentResource(ftl`
         foo = { $arg }
         `));
-      args = {
-        arg: 1
-      };
     });
 
     test('can be a number', function(){
       const msg = bundle.getMessage('foo');
-      const val = bundle.formatPattern(msg.value, args, errs);
+      const val = bundle.formatPattern(msg.value, {arg: 1}, errs);
       assert.strictEqual(val, '1');
       assert.strictEqual(errs.length, 0);
     });
+
+    test('can be a FluentNumber', function(){
+      const arg = new FluentNumber(1, {minimumFractionDigits: 2});
+      const msg = bundle.getMessage('foo');
+      const val = bundle.formatPattern(msg.value, {arg}, errs);
+      assert.strictEqual(val, '1.00');
+      assert.strictEqual(errs.length, 0);
+    });
   });
 
   suite('and dates', function(){
-    let args, dtf;
+    let dtf;
 
     suiteSetup(function() {
       dtf = new Intl.DateTimeFormat('en-US');
       bundle = new FluentBundle('en-US', { useIsolating: false });
       bundle.addResource(new FluentResource(ftl`
         foo = { $arg }
         `));
-      args = {
-        arg: new Date('2016-09-29')
-      };
     });
 
     test('can be a date', function(){
+      const arg = new Date('2016-09-29');
       const msg = bundle.getMessage('foo');
-      const val = bundle.formatPattern(msg.value, args, errs);
+      const val = bundle.formatPattern(msg.value, {arg}, errs);
       // format the date argument to account for the testrunner's timezone
-      assert.strictEqual(val, dtf.format(args.arg));
+      assert.strictEqual(val, dtf.format(arg));
+      assert.strictEqual(errs.length, 0);
+    });
+
+    test('can be a FluentDateTime', function(){
+      const arg = new FluentDateTime(new Date('2016-09-29'), {weekday: "long"});
+      const msg = bundle.getMessage('foo');
+      const val = bundle.formatPattern(msg.value, {arg}, errs);
+      assert.strictEqual(val, 'Thursday');
       assert.strictEqual(errs.length, 0);
     });
   });