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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /js/src/tests/non262/Intl/best-available-locale-from-default-locale.js | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/tests/non262/Intl/best-available-locale-from-default-locale.js')
-rw-r--r-- | js/src/tests/non262/Intl/best-available-locale-from-default-locale.js | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/js/src/tests/non262/Intl/best-available-locale-from-default-locale.js b/js/src/tests/non262/Intl/best-available-locale-from-default-locale.js new file mode 100644 index 0000000000..16a0e0348f --- /dev/null +++ b/js/src/tests/non262/Intl/best-available-locale-from-default-locale.js @@ -0,0 +1,107 @@ +// |reftest| skip-if(!this.hasOwnProperty('Intl')) + +if (typeof getDefaultLocale === "undefined") { + var getDefaultLocale = SpecialPowers.Cu.getJSTestingFunctions().getDefaultLocale; +} +if (typeof setDefaultLocale === "undefined") { + var setDefaultLocale = SpecialPowers.Cu.getJSTestingFunctions().setDefaultLocale; +} + +let defaultLocale = null; + +function withLocale(locale, fn) { + if (defaultLocale === null) + defaultLocale = getDefaultLocale(); + + setDefaultLocale(locale); + try { + fn(); + } finally { + setDefaultLocale(defaultLocale); + } +} + +// This test assumes Azerbaijani ("az") is a supported locale. +const supported = Intl.Collator.supportedLocalesOf("az"); +assertEq(supported.length, 1); +assertEq(supported[0], "az"); + +withLocale("az", () => { + // Ensure the new default locale is now active. + assertEq(new Intl.Collator().resolvedOptions().locale, "az"); + + // "az" is the active default locale, so explicitly requesting "az" should succeed. + assertEq(new Intl.Collator("az").resolvedOptions().locale, "az"); + + // ICU doesn't provide a specialised "az-Cyrl" locale, so we fallback to "az". + assertEq(new Intl.Collator("az-Cyrl").resolvedOptions().locale, "az"); + + // ICU doesn't provide a specialised "az-Cyrl-AZ" locale, so we fallback to "az". + assertEq(new Intl.Collator("az-Cyrl-AZ").resolvedOptions().locale, "az"); +}); + +// As demonstrated above, "az-Cyrl-AZ" normally isn't a supported Intl.Collator locale. But when +// used as the default locale, it gets promoted to being supported, because its parent locale "az" +// is supported and can act as a fallback. +// +// This works as follows: +// We accept any default locale as long as it can be supported either explicitly or implicitly +// through a fallback. But when we claim a default locale is supported, we also need to make sure +// we report any parent locale as being supported. So when "az-Cyrl-AZ" is accepted as the +// default locale, we also need to report its parent locale "az-Cyrl" as a supported locale. +// +// The reason we're doing this, is to make sure we aren't limiting the supported default locale to +// the intersection of the sets of supported locales for each Intl service constructor. Also see +// the requirements in <https://tc39.es/ecma402/#sec-internal-slots>, which state that the default +// locale must be a member of [[AvailableLocales]] for every Intl service constructor. +// +// So the following statement must hold: +// +// ∀ Constructor ∈ IntlConstructors: DefaultLocale ∈ Constructor.[[AvailableLocales]] +// +// This can trivially be achieved when we restrict the default locale to: +// +// { RequestedLocale if RequestedLocale ∈ (∩ C.[[AvailableLocales]]) +// { C ∈ IntlConstructors +// { +// DefaultLocale = { Fallback(RequestedLocale) if Fallback(RequestedLocale) ∈ (∩ C.[[AvailableLocales]]) +// { C ∈ IntlConstructors +// { +// { LastDitchLocale otherwise +// +// But that severely restricts the possible default locales. For example, "az-Cyrl-AZ" is supported +// by all Intl constructors except Intl.Collator. Intl.Collator itself only provides explicit +// support for the parent locale "az". So with the trivial solution we'd need to mark "az-Cyrl-AZ" +// as an invalid default locale and instead use its fallback locale "az". +// +// So instead of that we're using the following approach: +// +// { RequestedLocale if RequestedLocale ∈ (∩ C.[[AvailableLocales]]) +// { C ∈ IntlConstructors +// { +// DefaultLocale = { RequestedLocale if Fallback(RequestedLocale) ∈ (∩ C.[[AvailableLocales]]) +// { C ∈ IntlConstructors +// { +// { LastDitchLocale otherwise +// +// So even when the requested default locale is only implicitly supported through a fallback, we +// still accept it as a valid default locale. +withLocale("az-Cyrl-AZ", () => { + // Ensure the new default locale is now active. + assertEq(new Intl.Collator().resolvedOptions().locale, "az-Cyrl-AZ"); + + // "az-Cyrl-AZ" is the active default locale, so explicitly requesting the parent locale + // "az" should succeed. + assertEq(new Intl.Collator("az").resolvedOptions().locale, "az"); + + // "az-Cyrl-AZ" is the active default locale, so explicitly requesting the parent locale + // "az-Cyrl" should succeed. + assertEq(new Intl.Collator("az-Cyrl").resolvedOptions().locale, "az-Cyrl"); + + // "az-Cyrl-AZ" is the active default locale, so explicitly requesting "az-Cyrl-AZ" + // should succeed. + assertEq(new Intl.Collator("az-Cyrl-AZ").resolvedOptions().locale, "az-Cyrl-AZ"); +}); + +if (typeof reportCompare === "function") + reportCompare(0, 0); |