Shopify Functions Rust Crate

A crate to help developers build [Shopify Functions].

Dependencies

• Make sure you have graphql_client in your dependencies

  cargo add graphql_client@0.13.0

Usage

• The [generate_types] macro allows you to generate structs based on your [input query]. It will also generate output/response types for the current Function API, based on the provided schema.
  • It will automatically generate an .output.graphql file for code generation purposes. This file can be added to your .gitignore.
• The [shopify_function] attribute macro marks the following function as the entry point for a Shopify Function. It manages the Functions STDIN input parsing and STDOUT output serialization for you.
• The [run_function_with_input] function is a utility for unit testing which allows you to quickly add new tests based on a given JSON input string.

See the [example] for details on usage, or use the following guide to convert an existing Rust-based function.

Updating an existing function to use shopify_function

1. cargo add shopify_function
2. cargo add graphql_client@0.13.0
3. Delete src/api.rs.

4. In main.rs:

   1. Add imports for shopify_function.

      rust use shopify_function::prelude::*; use shopify_function::Result;

   2. Remove references to mod api.

   3. Add type generation, right under your imports.

      rust generate_types!(query_path = "./input.graphql", schema_path = "./schema.graphql");

   4. Remove the main function entirely.

   5. Attribute the function function with the shopify_function macro, and change its return type.

      ```rust

      [shopify_function]

      fn function(input: input::ResponseData) -> Result { ```

   6. Update the types and fields utilized in the function to the new, auto-generated structs. For example: | Old | New | | --- | --- | | input::Input | input::ResponseData | | input::Metafield | input::InputDiscountNodeMetafield | | input::DiscountNode | input::InputDiscountNode | | FunctionResult | output::FunctionResult | | DiscountApplicationStrategy::First | output::DiscountApplicationStrategy::FIRST |

5. Add .output.graphql to your .gitignore.

Viewing the generated types

To preview the types generated by the generate_types macro, use the cargo doc command.

bash cargo doc --open

You can also use the cargo-expand crate to view the generated source, or use the rust-analyzer VSCode extension to get IntelliSense for Rust and the generated types.

License Apache-2.0