@graphile/simplify-inflection

This preset simplifies field names in the PostGraphile schema; e.g. allUsers becomes simply users, User.postsByAuthorId becomes simply User.posts, and Post.userByAuthorId becomes simply Post.author.

Adding this preset to your schema is almost certainly a breaking change, so do it before you ship anything!

This preset is recommended for all PostGraphile users with a compatible database schema. The main reason this preset is not enabled by default is because it increases the risk of conflicts where multiple relationships try and use the same field name, and because some people name their primary key and foreign key columns in a way that would cause conflicts. Conflicts can be avoided by careful use of naming conventions or by specifically tagging the conflicting relations with their preferred name.

Incompatible database schemas

This plugin assumes that your primary key and foreign key columns are:

• named id, uuid, or pk; or
• named ending in _id, _uuid, or _pk; or
• named ending in Id, Uuid, or Pk.

If your database schema uses a different naming convention (and particularly if you name the primary key after the table itself, or the singularized version of it, with no prefix or suffix) then you are likely to receive a lot of naming conflicts if you use this plugin. If you are affected by this, this plugin is probably not for you (but feel free to fork it and make changes to accomodate your schemas naming conventions); however you may have luck using the "postgraphile/presets/relay" preset which hides primary key and foreign key columns throughout the schema, reducing the sources for these conflicts.

Customising

This preset is just one file, simply copy it into your project and customise it as you see fit.

Alternatively, you can write your own inflection plugin.

Changes:

Given these tables:

create table companies (
  id serial primary key,
  name text not null
);
create table beverages (
  id serial primary key,
  company_id int not null references companies,
  distributor_id int references companies,
  name text not null
);

• Query.allCompanies 👉 Query.companies (disable via pgSimplifyAllRows = false)
• Query.allBeverages 👉 Query.beverages
• Beverage.companyByCompanyId 👉 Beverage.company
• Beverage.companyByDistributorId 👉 Beverage.distributor
• Company.beveragesByCompanyId 👉 Company.beverages (because the company_id column follows the [table_name]_id naming convention)
• All update mutations now accept patch instead of companyPatch / beveragePatch (disable via pgSimplifyPatch = false)
• If you prefer lists then you can use pgOmitListSuffix = true to omit the List suffix, and instead append Connection to connections
• Fields where the singular and plural are the same and a distinct plural is required are force-pluralised ("fishes") to avoid conflicts (e.g. singularize("fish") === pluralize("fish")).

Note: Company.beveragesByDistributorId will remain, because distributor_id does not follow the [table_name]_id naming convention, but you could rename this yourself with a smart comment:

comment on constraint "beverages_distributor_id_fkey" on "beverages" is
  E'@foreignFieldName distributedBeverages';

or with a custom inflector plugin:

const plugin = {
  name: "MyCustomInflectionPlugin",
  version: "0.0.0",
  inflection: {
    replace: {
      getOppositeBaseName(previous, options, baseName) {
        return (
          {
            // These are the default opposites
            parent: "child",
            child: "parent",
            author: "authored",
            editor: "edited",
            reviewer: "reviewed",

            // 👇 Add/customise this line:
            distributor: "distributed",
          }[baseName] || previous(baseName)
        );
      },
    },
  },
};

Installation:

yarn add @graphile/simplify-inflection

or

npm install --save @graphile/simplify-inflection

Usage:

Add the preset to your Graphile Config file, under presets:

// graphile.config.mjs or similar

import { PgSimplifyInflectionPreset } from "@graphile/simplify-inflection";

export default {
  extends: [
    // ... (PostGraphileAmber, etc)
    PgSimplifyInflectionPreset,
  ],

  schema: {
    // ...
    /*
     * Uncomment if you want simple collections to lose the 'List' suffix
     * (and connections to gain a 'Connection' suffix).
     */
    //pgOmitListSuffix: true,
    /*
     * Uncomment if you want 'userPatch' instead of 'patch' in update
     * mutations.
     */
    //pgSimplifyPatch: false,
    /*
     * Uncomment if you want 'allUsers' instead of 'users' at root level.
     */
    //pgSimplifyAllRows: false,
    /*
     * Uncomment if you want primary key queries and mutations to have
     * `ById` (or similar) suffix; and the `nodeId` queries/mutations
     * to lose their `ByNodeId` suffix.
     */
    // pgShortPk: false,
  },
};

Naming your foreign key fields

By naming your foreign key along the lines of author_id or author_fk, e.g.:

CREATE TABLE posts (
  id serial primary key,
  author_id int not null references users,
  ...
);

We can automatically extract the field prefix: author and call the relation author rather than the default: user. This allows for a post to have an author, editor, reviewer, etc. all which point to users.

The reverse, however, is not so easy. On the User type, we can't call the reverse of all these different relations posts. The default inflector refers to these as postsByAuthorId, postsByEditorId, etc. However we'd rather use shorter names, so we introduce a new inflector: getOppositeBaseName. This inflector is passed a baseName (the part without the _id/_fk suffix, e.g. author, editor, reviewer above) and should return the opposite of that base name which will be prepended to the target type to produce, e.g. authoredPosts, editedPosts, reviewedPosts. Failing this, we just fall back to the default (verbose) inflector; it will be up to you to add smart comments or a custom inflector to override these.

Handling field conflicts:

In most cases, the conflict errors will guide you on how to fix these issues using smart comments.

Smart Tags

@listSuffix

@listSuffix allows you to override the default naming on a per-entity basis, overriding pgOmitListSuffix. For example, with pgOmitListSuffix: true, you can apply @listSuffix include to have the -List suffix appended to the simple collection generated for that table, and remove the -Connection suffix from the Relay connection. When pgOmitListSuffix is not true, you can use @listSuffix omit to selectively omit the -List suffix on simple collections and append -Connection to the Relay connection instead.

If @listSuffix is set, the only valid values are "omit" and "include". Any other value will cause an error.

| | @listSuffix omit | @listSuffix include | | ----------------: | :------------------ | :------------------ | | Relay Connection | companiesConnection | companies | | Simple Collection | companies | companiesList |

NOTE: @listSuffix will have no effect when using @foreignSimpleFieldName.

Applies to:

• tables
• foreign key constraints
• computed column functions returning SETOF <record type>