52 lines
2.9 KiB
Markdown
52 lines
2.9 KiB
Markdown
---
|
|
title: Paths in Quartz
|
|
---
|
|
|
|
Paths are pretty complex to reason about because, especially for a static site generator, they can come from so many places.
|
|
|
|
A full file path to a piece of content? Also a path. What about a slug for a piece of content? Yet another path.
|
|
|
|
It would be silly to type these all as `string` and call it a day as it's pretty common to accidentally mistake one type of path for another. Unfortunately, TypeScript does not have [nominal types](https://en.wikipedia.org/wiki/Nominal_type_system) for type aliases meaning even if you made custom types of a server-side slug or a client-slug slug, you can still accidentally assign one to another and TypeScript wouldn't catch it.
|
|
|
|
Luckily, we can mimic nominal typing using [brands](https://www.typescriptlang.org/play#example/nominal-typing).
|
|
|
|
```typescript
|
|
// instead of
|
|
type FullSlug = string
|
|
|
|
// we do
|
|
type FullSlug = string & { __brand: "full" }
|
|
|
|
// that way, the following will fail typechecking
|
|
const slug: FullSlug = "some random string"
|
|
```
|
|
|
|
While this prevents most typing mistakes _within_ our nominal typing system (e.g. mistaking a server slug for a client slug), it doesn't prevent us from _accidentally_ mistaking a string for a client slug when we forcibly cast it.
|
|
|
|
Thus, we still need to be careful when casting from a string to one of these nominal types in the 'entrypoints', illustrated with hexagon shapes in the diagram below.
|
|
|
|
The following diagram draws the relationships between all the path sources, nominal path types, and what functions in `quartz/path.ts` convert between them.
|
|
|
|
```mermaid
|
|
graph LR
|
|
Browser{{Browser}} --> Window{{Body}} & LinkElement{{Link Element}}
|
|
Window --"getFullSlug()"--> FullSlug[Full Slug]
|
|
LinkElement --".href"--> Relative[Relative URL]
|
|
FullSlug --"simplifySlug()" --> SimpleSlug[Simple Slug]
|
|
SimpleSlug --"pathToRoot()"--> Relative
|
|
SimpleSlug --"resolveRelative()" --> Relative
|
|
MD{{Markdown File}} --> FilePath{{File Path}} & Links[Markdown links]
|
|
Links --"transformLink()"--> Relative
|
|
FilePath --"slugifyFilePath()"--> FullSlug[Full Slug]
|
|
style FullSlug stroke-width:4px
|
|
```
|
|
|
|
Here are the main types of slugs with a rough description of each type of path:
|
|
|
|
- `FilePath`: a real file path to a file on disk. Cannot be relative and must have a file extension.
|
|
- `FullSlug`: cannot be relative and may not have leading or trailing slashes. It can have `index` as it's last segment. Use this wherever possible is it's the most 'general' interpretation of a slug.
|
|
- `SimpleSlug`: cannot be relative and shouldn't have `/index` as an ending or a file extension. It _can_ however have a trailing slash to indicate a folder path.
|
|
- `RelativeURL`: must start with `.` or `..` to indicate it's a relative URL. Shouldn't have `/index` as an ending or a file extension but can contain a trailing slash.
|
|
|
|
To get a clearer picture of how these relate to each other, take a look at the path tests in `quartz/util/path.test.ts`.
|