Improve test coverage

[curbengh]

Check List

Please check followings before submitting a new feature request.

• [x] I have already read Docs page
• [x] I have already searched existing issues

Feature Request

This repo's unit test coverage currently stands at .

For anyone who is interested in improving it, there are a few ways:

1. Search for "missing-unit-test" to locate functions that haven't been covered.
2. Click on the coverage badge link and it shows all the relevant lines.
3. Line coverage report is also shown in the CI job log.

hexo-util also needs help.

[seaoak]

@curbengh Thank you for nice waking-up call!

I checked a "missing-unit-test" point of hexo-util. https://github.com/hexojs/hexo-util/blob/master/test/highlight.spec.js#L172

I found that highlight() of hexo-util might not work well for illegal syntax codes. highlight() of highlightjs package will throw an exception if source text is illegal syntax codes. https://highlightjs.readthedocs.io/en/latest/api.html#highlight-languagename-code-ignore-illegals-continuation

But hexo-util/lib/highlight.js might not consider that case.

I continue to investigate this issue (and make new issue in the repo of hexo-util).

[SukkaW]

After #4422, the coverage has been increased from 97.03% to 98.26%.

[stevenjoezhang]

npx c8 report --reporter=lcov --reporter=text

File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	99.54	96.22	99.14	99.54
box	96.53	95.23	100	96.53
file.ts	100	100	100	100
index.ts	96.02	94.93	100	96.02	...62,274-276,280-282
extend	100	96.16	100	100
console.ts	100	100	100	100
deployer.ts	100	100	100	100
filter.ts	100	97.5	100	100	71
generator.ts	100	100	100	100
helper.ts	100	100	100	100
index.ts	100	100	100	100
injector.ts	100	92.5	100	100	63,74-79
migrator.ts	100	100	100	100
processor.ts	100	100	100	100
renderer.ts	100	96.55	100	100	5
syntax_highlight.ts	100	62.5	100	100	43,55-57
tag.ts	100	96.92	100	100	120,182
hexo	99.33	96.19	98.94	99.33
default_config.ts	100	100	100	100
index.ts	99.27	95.78	96.15	99.27	330-331,508-510
load_config.ts	100	91.3	100	100	30,47
load_database.ts	100	100	100	100
load_plugins.ts	97.56	94.28	100	97.56	56,75
load_theme_config.ts	100	100	100	100
locals.ts	100	100	100	100
multi_config_path.ts	100	100	100	100
post.ts	99.79	95.74	100	99.79	194
register_models.ts	100	100	100	100
render.ts	96.37	92.59	100	96.37	23-27
router.ts	99.46	96.61	100	99.46	71
scaffold.ts	100	100	100	100
source.ts	100	100	100	100
update_package.ts	100	100	100	100
validate_config.ts	100	100	100	100
models	99.65	92.85	100	99.65
asset.ts	100	100	100	100
cache.ts	100	100	100	100
category.ts	100	84.21	100	100	23,33,62
data.ts	100	100	100	100
index.ts	100	100	100	100
page.ts	100	100	100	100
post.ts	99.11	94.02	100	99.11	106,183
post_asset.ts	100	100	100	100
post_category.ts	100	100	100	100
post_tag.ts	100	100	100	100
tag.ts	100	82.35	100	100	12,17,55
models/types	100	95.34	100	100
moment.ts	100	95.34	100	100	80,85
plugins/console	99.83	96.47	100	99.83
clean.ts	100	100	100	100
config.ts	100	100	100	100
deploy.ts	100	93.75	100	100	41
generate.ts	99.52	94.82	100	99.52	113
index.ts	100	100	100	100
migrate.ts	100	100	100	100
new.ts	100	100	100	100
publish.ts	100	100	100	100
render.ts	100	85.71	100	100	32
plugins/console/list	100	97.05	100	100
category.ts	100	100	100	100
common.ts	100	100	100	100
index.ts	100	100	100	100
page.ts	100	100	100	100
post.ts	100	83.33	100	100	14
route.ts	100	100	100	100
tag.ts	100	100	100	100
plugins/filter	100	100	100	100
index.ts	100	100	100	100
new_post_path.ts	100	100	100	100
post_permalink.ts	100	100	100	100
plugins/filter/after_post_render	100	100	100	100
excerpt.ts	100	100	100	100
external_link.ts	100	100	100	100
index.ts	100	100	100	100
plugins/filter/after_render	100	95.23	100	100
external_link.ts	100	92.3	100	100	11
index.ts	100	100	100	100
meta_generator.ts	100	100	100	100
plugins/filter/before_exit	100	100	100	100
index.ts	100	100	100	100
save_database.ts	100	100	100	100
plugins/filter/before_generate	100	100	100	100
index.ts	100	100	100	100
render_post.ts	100	100	100	100
plugins/filter/before_post_render	100	96.29	100	100
backtick_code_block.ts	100	94.44	100	100	26
index.ts	100	100	100	100
titlecase.ts	100	100	100	100
plugins/filter/template_locals	100	100	100	100
i18n.ts	100	100	100	100
index.ts	100	100	100	100
plugins/generator	100	100	100	100
asset.ts	100	100	100	100
index.ts	100	100	100	100
page.ts	100	100	100	100
post.ts	100	100	100	100
plugins/helper	99.7	96.2	96.2	99.7
css.ts	100	100	100	100
date.ts	100	100	100	100
debug.ts	100	100	100	100
favicon_tag.ts	100	100	100	100
feed_tag.ts	100	100	100	100
format.ts	80	100	62.5	80	6-8
fragment_cache.ts	100	100	100	100
full_url_for.ts	100	100	100	100
gravatar.ts	100	100	100	100
image_tag.ts	100	100	100	100
index.ts	100	100	100	100
is.ts	100	100	100	100
js.ts	100	100	100	100
link_to.ts	100	100	100	100
list_archives.ts	100	97.22	100	100	44
list_categories.ts	100	91.11	100	100	9,53,85-93
list_posts.ts	100	83.33	100	100	29,45-48
list_tags.ts	100	91.89	100	100	10,75,77
mail_to.ts	100	100	100	100
markdown.ts	100	100	100	100
meta_generator.ts	100	100	100	100
number_format.ts	100	92.85	100	100	37
open_graph.ts	99	94.87	100	99	43-44
paginator.ts	100	97.5	100	100	117
partial.ts	100	100	100	100
relative_url.ts	100	100	100	100
render.ts	100	100	100	100
search_form.ts	100	100	100	100
tagcloud.ts	100	95.45	100	100	30,52
toc.ts	100	100	100	100
url_for.ts	100	100	100	100
plugins/highlight	100	92	100	100
highlight.ts	100	92.85	100	100	5
index.ts	100	100	100	100
prism.ts	100	90	100	100	5
plugins/injector	100	100	100	100
index.ts	100	100	100	100
plugins/processor	99.62	96.17	100	99.62
asset.ts	100	100	100	100
common.ts	100	100	100	100
data.ts	100	90	100	100	28
index.ts	100	100	100	100
post.ts	99.32	94.11	100	99.32	233-234
plugins/renderer	95.31	96.96	100	95.31
index.ts	100	100	100	100
json.ts	100	100	100	100
nunjucks.ts	100	100	100	100
plain.ts	100	100	100	100
yaml.ts	72.72	50	100	72.72	11-16
plugins/tag	100	98.17	100	100
asset_img.ts	100	100	100	100
asset_link.ts	100	100	100	100
asset_path.ts	100	100	100	100
blockquote.ts	100	95.45	100	100	26
code.ts	100	96.87	100	100	70
full_url_for.ts	100	100	100	100
iframe.ts	100	100	100	100
img.ts	100	100	100	100
include_code.ts	100	93.33	100	100	43
index.ts	100	100	100	100
link.ts	100	100	100	100
post_link.ts	100	100	100	100
post_path.ts	100	100	100	100
pullquote.ts	100	100	100	100
url_for.ts	100	100	100	100
theme	100	93.75	100	100
index.ts	100	90	100	100	82
view.ts	100	94.73	100	100	10,132
theme/processors	100	96	100	100
config.ts	100	100	100	100
i18n.ts	100	75	100	100	18
source.ts	100	100	100	100
view.ts	100	100	100	100