@syncify/codegen v0.0.1

@syncify/codegen

A streamlined tool for extracting a normalized GraphQL introspection schema from the Shopify GraphQL API. This module serves as a drop-in replacement for generating clean, concise types when working with Shopify's GraphQL schema. It operates as a post-processing step, enabling selective extraction of only the types you need.

Key Features

• Selective Type Extraction: Cherry-pick specific types from the GraphQL schema, reducing clutter.
• Scalar Normalization: Enforces native type narrowing for cleaner definitions.
• Controlled Depth Extraction: Includes sensible logic to limit schema depth.
• Accurate Mutation Payloads: Generates types that match actual response structures.
• Query-Specific Types: Tailors object types for read operations.

Why Not Use Shopify’s Codegen Preset?

While Shopify’s open-source tools are commendable, their codegen preset falls short for practical use. It produces a bloated 55k-line definition file, overwhelming the TypeScript parser. Even with caching, this massive output slows down IntelliSense, hampering developer productivity. Native codegen lacks selective type extraction, forcing you to grapple with the full introspection schema when you may only need a handful of interfaces. This module addresses these pain points with a smarter, more efficient approach.

Installation

Install @syncify/codegen as a devDependency in your project:

pnpm add @syncify/codegen -D

Prerequisites

• Node.js (>= 14.x)
• GraphQL Codegen (@graphql-codegen/cli, @graphql-codegen/typescript)
• TypeScript (>= 4.x)
• Prettier (optional, for formatting output)

Ensure you have the GraphQL Codegen CLI installed globally or as a dev dependency:

pnpm install --save-dev @graphql-codegen/cli @graphql-codegen/typescript

Configuration

@syncify/codegen accepts the following configuration options in your codegen.yml:

Example Configuration

generates:
  ./generated/types.ts:
    plugins:
      - 'typescript'
      - '@syncify/codegen'
    config:
      pickTypes: ['Market', 'Translation']
      depthInclusion: 1
      skipTypeName: true

• pickTypes: Includes Market, Translation, and default types (DisplayableError, PageInfo, UserError, Node).
• depthInclusion: 1: Includes direct dependencies of the picked types (depth 1).
• skipTypeName: true: Omits __typename fields from the output.

Features in Detail

Scalar Normalization

Maps GraphQL scalars to appropriate TypeScript types, reducing reliance on any:

• ID, String, DateTime → string
• Int, Float → number
• Boolean → boolean
• JSON → Record<string, any>

Controlled Depth Extraction

Use depthInclusion to limit how deeply dependencies are extracted:

• depthInclusion: 0: Only the picked types.
• depthInclusion: 1: Picked types and their direct dependencies (default).
• depthInclusion: Infinity: All dependencies.

Accurate Mutation Payloads

Transforms mutation payloads (e.g., SomeMutationPayload) into a normalized form (e.g., MutationSomeMutation), wrapping the response in a single property:

Input:

type SomeTypeNamePayload = {
  someResult?: SomeType;
  userErrors: UserError[];
};

Output:

export type MutationSomeTypeName = {
  someTypeName: { someResult: SomeType };
};

Query-Specific Types

Generates query-specific types from QueryRoot, structuring them as single-property objects, unwrapping Maybe where appropriate:

Input:

type QueryRoot = {
  product: Maybe<Product>;
};

Output:

export type QueryProduct = {
  product: Product;
};

Example

Here’s a complete example to generate types for a Shopify schema.

codegen.yml

schema: 'https://your-shopify-store.myshopify.com/api/2024-07/graphql.json'
generates:
  ./generated/types.ts:
    plugins:
      - 'typescript'
      - '@syncify/codegen'
    config:
      pickTypes: ['Product', 'Order']
      depthInclusion: 2

Run the Command

npx graphql-codegen --config codegen.yml

Output (generated/types.ts)

/* eslint-disable no-use-before-define */

/**
 * Represents a product in the shop.
 */
export type Product = {
  id: string;
  title: string;
  variants: Variant[];
};

/**
 * Represents an order placed in the shop.
 */
export type Order = {
  id: string;
  totalPrice: string;
  lineItems: LineItem[];
};

/**
 * Default type always included.
 */
export type DisplayableError = {
  field?: Array<string>;
  message: string;
};

// ... other default types (PageInfo, UserError, Node)

Troubleshooting

"Type X not found in source"

• Cause: A type specified in pickTypes doesn’t exist in the schema.
• Solution: Verify the type name against the schema (case-sensitive). Check the API version in your schema URL.

Output File Too Large

• Cause: High depthInclusion value or complex types with many dependencies.
• Solution: Reduce depthInclusion (e.g., depthInclusion: 1) or pick fewer types.

Missing __typename Fields

• Cause: skipTypeName: true removes __typename from the output.
• Solution: Set skipTypeName: false if you need these fields.