https://github.com/parsonsmatt/persistent-discover

Discover your Persistent Models with Ease
https://github.com/parsonsmatt/persistent-discover

Last synced: 10 days ago
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Discover your Persistent Models with Ease

• Host: GitHub
• URL: https://github.com/parsonsmatt/persistent-discover
• Owner: parsonsmatt
• License: bsd-3-clause
• Created: 2021-05-06T18:36:52.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2023-10-04T00:30:09.000Z (about 1 year ago)
• Last Synced: 2024-04-25T18:00:43.905Z (6 months ago)
• Language: Haskell
• Size: 32.2 KB
• Stars: 4
• Watchers: 3
• Forks: 3
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • Changelog: ChangeLog.md
  • License: LICENSE

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README

        
# persistent-discover

![build status](https://github.com/parsonsmatt/persistent-discover/actions/workflows/haskell.yml/badge.svg)

Supports automatic discovery of your

[`persistent`](https://hackage.haskell.org/package/persistent) models.

## As an executable

Let's say you've got a ton of `persistent` database models, all defined in a

module hierarchy like this:

```

src/

  Models/

    Foo.hs

    Bar.hs

    Baz.hs

    Blargh.hs

    What.hs

    OhNo.hs

```

If you're using `persistent` to automatically generate migrations, you'll want

to have all the `[EntityDef]` in scope from each module. You can do that by

importing each module that defines models and calling `$(discoverEntities)`,

introduced in `persistent-2.13`.

But you may forget to import a module.

This utility imports *all* the modules defined in the current directory and

sub-directories, and then it calls `$(discoverEntities)` for you.

To use it, place the following command in a file, located in the same directory

that your Haskell modules are in:

```

{-# OPTIONS_GHC -F -pgmF persistent-discover #-}

```

Let's say we put that in `src/Models/All.hs`.

This generates a module `Models.All` that exports a single item: `allEntities`,

which is a `[EntityDef]` and can be used by `migrateModels` to properly perform

migrations.

You'll need to add `persistent-discover` to the `build-tool-depends` on your cabal file

for this to work.