Added regression tests for navigation

See the change to `_config.yml` for how to activate the tests.

_config.yml

@@ -19,7 +19,15 @@ baseurl: "/just-the-docs" # the subpath of your site, e.g. /blog
 url: "https://pmarsceill.github.io" # the base hostname & protocol for your site, e.g. http://example.com
 
 permalink: pretty
-exclude: ["node_modules/", "*.gemspec", "*.gem", "Gemfile", "Gemfile.lock", "package.json", "package-lock.json",  "script/", "LICENSE.txt", "lib/", "bin/", "README.md", "Rakefile", "docs/tests/"]
+exclude: ["node_modules/", "*.gemspec", "*.gem", "Gemfile", "Gemfile.lock", "package.json", "package-lock.json",  "script/", "LICENSE.txt", "lib/", "bin/", "README.md", "Rakefile"
+, "docs/tests/"
+]
+
+# Regression tests
+# By default, the pages in /docs/tests are excluded when the ste is built.
+# To include them, comment-out the relevant line above.
+# Uncommenting the following line doesn't work - see https://github.com/jekyll/jekyll/issues/4791
+# include: ["docs/tests/"]
 
 # Set a path/url to a logo that will be displayed instead of the title
 #logo: "/assets/images/just-the-docs.png"

docs/tests/42.md

----
-layout: default
-title: 42
-search_exclude: true
----
-
-# The answer is 42
-
-A link to this page should appear in the navigation after all pages where
-the `nav_order` value is a number, because titles are treated as strings
-when used as default `nav_order`s.

docs/tests/index.md

+---
+layout: default
+title: Tests
+has_children: true
+nav_order: 100
+---
+
+# Tests
+
+ The main documentation pages of this theme illustrate the use of many of its features, which to some extent tests their implementation. The pages linked below provide further test cases for particular features, and may be useful for regression testing when developing new features.
+ 
+The default configuration does not include the test pages. To include them, add the following option to `_config.yml':
+
+```yaml
+include: ["docs/tests/"]
+```

docs/tests/navigation/exclude/excluded-child.md

+---
+layout: default
+title: Excluded Child
+parent: Not Excluded
+nav_exclude: true
+---
+# Excluded Child
+
+This child page is explicitly excluded, and should not appear in the navigation.
+
+```yaml
+title: Excluded Child
+parent: Not Excluded
+nav_exclude: true
+```

docs/tests/navigation/exclude/excluded-grandchild.md

+---
+layout: default
+title: Excluded Grandchild
+parent: Non-excluded Child
+grand_parent: Non-excluded
+nav_exclude: true
+---
+# Excluded Grandchild
+
+This grandchild page is explicitly excluded, and should not appear in the navigation.
+
+```yaml
+title: Excluded Grandchild
+parent: Non-excluded Child
+grand_parent: Non-excluded
+nav_exclude: true
+```

docs/tests/navigation/exclude/excluded.md

+---
+layout: default
+title: Excluded
+has_children: true
+nav_exclude: true
+---
+# Excluded
+
+This top-level page is explicitly excluded, and should not appear in the navigation. Any child pages are implicitly excluded.
+
+```yaml
+title: Excluded
+has_children: true
+nav_exclude: true
+```

docs/tests/navigation/exclude/non-excluded-child-of-excluded.md

+---
+layout: default
+title: Non-excluded Child of Excluded
+parent: Excluded
+nav_exclude: false
+---
+# Non-excluded Child of Excluded
+
+This child page is explicitly not excluded, but its parent page is excluded, so it should not appear in the navigation.
+
+```yaml
+title: Non-excluded Child of Excluded
+parent: Excluded
+nav_exclude: false
+```

docs/tests/navigation/exclude/non-excluded-child.md

+---
+layout: default
+title: Non-excluded Child
+parent: Non-excluded
+has_children: true
+nav_exclude: false
+---
+# Non-excluded Child
+
+This child page is explicitly not excluded, and should appear in the navigation.
+
+```yaml
+title: Non-excluded Child
+parent: Non-excluded
+nav_exclude: false
+```

docs/tests/navigation/exclude/non-excluded-grandchild-of-excluded.md

+---
+layout: default
+title: Non-excluded Grandchild of Excluded
+parent: Non-excluded Child
+grand_parent: Excluded
+nav_exclude: false
+---
+# Non-excluded Grandchild of Excluded
+
+This grandchild page is explicitly not excluded, and neither is its parent page; but its grandparent page is excluded, so it should not appear in the navigation.
+
+```yaml
+title: Non-excluded Grandchild of Excluded
+parent: Non-excluded Child
+grand_parent: Excluded
+nav_exclude: false
+```

docs/tests/navigation/exclude/non-excluded-grandchild.md

+---
+layout: default
+title: Non-excluded Grandchild
+parent: Non-excluded Child
+grand_parent: Non-excluded
+nav_exclude: false
+---
+# Non-excluded Grandchild
+
+This grandchild page is explicitly not excluded, and neither is its parent page nor its grandparent page, so it should appear in the navigation.
+
+```yaml
+title: Non-excluded Grandchild of Excluded
+parent: Non-excluded Child
+grand_parent: Excluded
+nav_exclude: false
+```

docs/tests/navigation/exclude/non-excluded.md

+---
+layout: default
+title: Non-excluded
+has_children: true
+nav_exclude: false
+---
+# Non-excluded
+
+This top-level page is explicitly not excluded, and should appear in the navigation.
+
+```yaml
+title: Non-excluded
+nav_exclude: false
+```

docs/tests/navigation/exclude/untitled.md

+---
+layout: default
+---
+# Untitled
+
+This page has no `title`, and should not appear in the navigation.

docs/tests/navigation/grandparent/a.md

+---
+layout: default
+title: A
+has_children: true
+---
+
+# A
+
+A top-level page
+
+```yaml
+title: A
+has_children: true
+```

docs/tests/navigation/grandparent/b.md

+---
+layout: default
+title: B
+has_children: true
+---
+
+# B
+
+A top-level page
+
+```yaml
+title: B
+has_children: true
+```

docs/tests/navigation/grandparent/ca.md

+---
+layout: default
+title: C
+parent: A
+has_children: true
+---
+
+# C
+
+A child of page A, and parent of page D
+
+```yaml
+title: C
+parent: A
+has_children: true
+```

docs/tests/navigation/grandparent/cb.md

+---
+layout: default
+title: C
+parent: B
+has_children: true
+---
+
+# C
+
+A child of page B, and parent of page D
+
+```yaml
+title: C
+parent: B
+has_children: true
+```

docs/tests/navigation/grandparent/dca.md

+---
+layout: default
+title: D
+parent: C
+grand_parent: A
+---
+
+# D
+
+A grandchild of page A
+
+```yaml
+title: D
+parent: C
+grand_parent: A
+```

docs/tests/navigation/grandparent/dcb.md

+---
+layout: default
+title: D
+parent: C
+grand_parent: B
+---
+
+# D
+
+A grandchild of page B
+
+```yaml
+title: D
+parent: C
+grand_parent: B
+```

docs/tests/navigation/index.md

+---
+layout: default
+title: Navigation
+parent: Tests
+---
+
+# Navigation
+
+## Parent page disambiguation
+
+- [Page A](grandparent/a/) has a child [page with title C](grandparent/ca/), and a grandchild [page with title D](grandparent/dca/).
+- [Page B](grandparent/b/) has a child [page with title C](grandparent/cb/), and a grandchild [page with title D](grandparent/dcb/).
+- The grandchild pages specify their parent and grandparent pages, so there is no ambiguity.
+
+## Page exclusion
+
+- An [untitled page](exclude/untitled/) is excluded from the navigation.
+- An excluded [top level page](exclude/excluded/), [child page](exclude/excluded-child/), or [grandchild page](exclude/excluded-grandchild/) does not appear.
+- A non-excluded [top level page](exclude/non-excluded/) appears; and a non-excluded [child page](exclude/non-excluded-child/) or [grandchild page](exclude/non-excluded-grandchild/) appears if its parent appears.
+- A non-excluded child page or grandchild page does not appear if its parent is excluded.
+
+## Page order
+
+- [Default](order/default/), using `title` instead of `nav_order` fields.
+- [Strings](order/strings/), lexicographically ordered, possibly case-insensitively.
+- [Integers](order/integers/), numerically ordered.
+- [Floats](order/floats/), numerically ordered.
+- [Mixture](order/mixture/), with numbers before strings.

docs/tests/navigation/order/default/10.md

+---
+layout: default
+title: "10"
+parent: Default
+grand_parent: Order
+---
+
+# 10
+
+```yaml
+title: "10"
+parent: Default
+grand_parent: Order
+```