Test X Fern Global Parameters Extension Custom Commands

Custom Commands for test-x-fern-global-parameters-extension

Overview

The test-x-fern-global-parameters-extension CLI supports user-authored custom commands that are compiled into the binary alongside the auto-generated API commands. Custom commands get a fully-wired SDK client that inherits the CLI's auth, retries, TLS, base URL, and global headers — zero configuration required.

Architecture

cli/test-x-fern-global-parameters-extension/custom.rs    ← Your command handlers (protected by .fernignore)
cli/test-x-fern-global-parameters-extension/sdk.rs       ← Generated bridge: client() + block_on()
cli/test-x-fern-global-parameters-extension/main.rs      ← Generated entrypoint (calls custom::register)
test-x-fern-global-parameters-extension-sdk/             ← Co-generated typed SDK crate
test-x-fern-global-parameters-extension-types/           ← Co-generated typed model crate

Adding a Custom Command

1. Edit cli/test-x-fern-global-parameters-extension/custom.rs

This file is protected by .fernignore — fern generate will never overwrite it. Register commands in the register() function:

use test_x_fern_global_parameters_extension_sdk::api::*;

pub fn register(app: CliApp) -> CliApp {
    let app = app.command(
        clap::Command::new("get")
            .about("Run products get")
            .arg(clap::Arg::new("regionId").required(true))
            .arg(clap::Arg::new("productId").required(true))
        ,
        |matches, ctx| {
            let region_id = matches.get_one::<String>("regionId").unwrap();
            let product_id = matches.get_one::<String>("productId").unwrap();
            let client = super::sdk::client(ctx);
            let result = super::sdk::block_on(
                client.products.get(region_id, product_id),
            )?;
            println!("{}", serde_json::to_string_pretty(&result).unwrap());
            Ok(())
        },
    );
    app
}

Then build and test:

cargo build
test-x-fern-global-parameters-extension get <regionId> <productId>

2. Available SDK Clients

The super::sdk::client(ctx) call returns a test_x_fern_global_parameters_extension_sdk::api::Client with the following sub-clients:

3. Key Patterns

Get the SDK client (execution-sharing, fully authenticated):

let client = super::sdk::client(ctx);

Run an async SDK call from a sync handler:

let result = super::sdk::block_on(
    client.some_resource.some_method(args),
)?;

Use typed models for request/response serialization:

use test_x_fern_global_parameters_extension_sdk::api::*;

Regeneration Safety

After running fern generate, your custom.rs is preserved. All generated code (SDK, types, glue, main.rs) is updated to match the latest API spec. If the SDK surface changes (renamed methods, new sub-clients), update your custom.rs to match.

Build & Test

# Build the CLI (includes custom commands)
cargo build

# Run your custom command
test-x-fern-global-parameters-extension <your-command> [args]

# Run with verbose output for debugging
RUST_LOG=debug test-x-fern-global-parameters-extension <your-command> [args]