Use default language when no language set

[bobd91]

Use default language when no language set, or there is no translation for specified language

If no language is set in _config, or the theme has no language file for the one set, then the translation data is chosen in indeterminate manner as it is taken from a list of all available translations returned by hexo.theme.i18n#list().

The changes to lib/plugins/filter/template_locals/i18n.js use i18n.languages in preference to config.language and i18n.list() as this provides an array of configured languages with 'default' on the end. This ensures that if no language is set or the language cannot be found then then default translation will be used.

The changes to test/scripts/filters/i18n_locals.js set i18n.languages rather than config.language as the original test code did not set the 'default' language correctly.

Added two tests

• use config by default - with no languages, default language should be used
• use config by default - with unknown language, default language should be used

Both of the new tests fail on the current release but pass with the changes in the pull request.

This is a fix for #1125

[coveralls]

Coverage decreased (-0.02%) to 97.251% when pulling 057229c on bobd91:default-language into 940495c on hexojs:master.

[coveralls]

Coverage decreased (-0.002%) to 97.274% when pulling 65301af on bobd91:default-language into 940495c on hexojs:master.

[coveralls]

Coverage decreased (-0.02%) to 97.251% when pulling 057229c on bobd91:default-language into 940495c on hexojs:master.

[bobd91]

LOL, if you remove code then the coverage % goes down even though all of the code you have changed is covered!
I only removed the code in the first place as my original changes caused a particular branch to never be executed (code run if variable is not an array on something that is now always an array).
Feeling frustrated with coveralls.

[JLHwung]

Good catch and thanks!

[ivan-nginx]

If no language is set in _config, or the theme has no language file for the one set, then the translation data is chosen in indeterminate manner as it is taken from a list of all available translations returned by hexo.theme.i18n#list().

Not indeterminate manner, but take first catched language in themes/languages directory. So, if first language will de.yml, it's will set DE language if this 2 cases above will reproduce.

For now this pull create 1 additional bug in NexT theme: if 2 cases above will reproduce and default.yml not exists in themes/languages directory, no one language will be selected. So, for now it's mean need to create 1 additional symlink or rename en.yml on default.yml, but before this pull this bug was solved just by renaming en.yml on _en.yml.

Breaking Changes for most Hexo themes

This pull with 2 cases above will brake many themes in which default.yml in themes/languages not exists. There is the list:

• NexT (already fixed after check this changes) (old NexT exists duplicate default.yml file of en.yml)
• Tranquilpeak
• Yilia (en.yml renamed on default.yml by default)
• Indigo
• Material
• Icarus
• Apollo
• Hueman
  And many other themes which authors don't know this bug cases, looks like this:
  

So, this bugfix now produce ≈ 80% breaking changes for all Hexo themes.
@JLHwung, @NoahDragon, please, test pulls like that before merge for all possible breaking changes, Thank's!

Possible fixes for this changes

This ensures that if no language is set or the language cannot be found then default translation will be used.

Use first language in list (instead of this) if default.yml file not exists.

[bobd91]

Not indeterminate manner, but take first catched language in themes/languages directory.

On your system maybe, but the order of the language files is dependent upon the order that Node's readdir function provides. It is well documented that Node's readdir on Windows does not provide a sorted list and even on Linux the underlying readdir C function makes no promises on ordering.

[ivan-nginx]

Node's readdir on Windows does not provide a sorted list and even on Linux the underlying readdir C function makes no promises on ordering.

It's alphabetical or vice-versa. Will be load first or last language. But it's can't load random language, i think. So, it can't be called indeterminate manner.

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Anyway, default platform is Linux and as i say here, this fix for now worse then was before.