deno-slack-runtime

Helper library for running a Run on Slack Deno function. The goal of this project is to provide modules for:

1. Parsing function execution event payloads into JSON (src/parse-payload.ts)
2. Dynamically loading the target function (src/load-function-module.ts)
3. Dispatching event payloads to individual functions by callback ID and running them (src/dispatch-payload.ts)

This library has two modes of operation:

1. Using mod.ts as the entrypoint, a directory containing function code files to be loaded at runtime must be provided as an argument. This directory must contain one source file per function, with each filename matching the function ID, i.e. if a function to be invoked has a callback_id of reverse, the provided directory argument must contain a reverse.ts or a reverse.js.
2. Using local-run.ts as the entrypoint, the current working directory must contain a manifest.json, manifest.ts or manifest.js file, which in turn must contain function definitions that include a source_file property. This property is used to determine which function to load and run at runtime.

Regardless of which mode of operation used, each runtime definition for a function is specified in its own file and must be the default export.

Usage

By default, your Slack app has a /slack.json file that defines a get-hooks hook. The Slack CLI will automatically use the version of the deno-slack-runtime that is specified by the version of the get-hooks script that you’re using. To use this library via the Slack CLI out of the box, use the slack run command in your terminal. This will automatically run the start hook and wait for events to parse the payload.

Override

You also have the option to override this hook! You can change the script that runs by specifying a new script for the start command. For instance, if you wanted to point to your local instance of this repo, you could accomplish that by adding a start command to your /slack.json file and setting it to the following:

{
  "hooks": {
    /* ... */
    "start": "deno run -q --config=deno.jsonc --allow-read --allow-net file:///<path-to-your-local-repo>/local-run.ts"
  }
}

The script may be one of the following, depending on which mode you are operating this library in:

1. Explicit function directory as argument: deno run -q --config=deno.jsonc --allow-read --allow-net https://deno.land/x/deno_slack_runtime@0.1.1/mod.ts ./<required-function-directory>
2. Local project with a manifest file: deno run -q --config=deno.jsonc --allow-read --allow-net https://deno.land/x/deno_slack_runtime@0.1.1/local-run.ts

⚠️ Don’t forget to update the version specifier in the URL inside the above commands to match the version you want to test! You can also drop the @ and the version specifier to use the latest released version. You can also use the file:/// protocol to point to a version present on your local filesystem.

CLI

You can also invoke this library directly from the command line:

deno run -q --config=deno.jsonc --allow-read --allow-net https://deno.land/x/deno_slack_runtime@0.1.1/mod.ts [-p <port>]

Which will start an API Server that will exectue user provided code

GET /health

Returns 200 OK when called, the runtime will use this route to ensure the server is ready to handle requests

POST /functions

Post Body contains the event payload that used to be read via stdout. Returns 200 OK when there are no errors with finding and executing the expected user code. Will return a 500 otherwise.

Running Tests

If you make changes to this repo, or just want to make sure things are working as desired, you can run:

deno task test

To get a full test coverage report, run:

deno task coverage

Getting Help

We welcome contributions from everyone! Please check out our Contributor’s Guide for how to contribute in a helpful and collaborative way.