Edge Functions

Testing your Edge Functions

Writing Unit Tests for Edge Functions using Deno Test

Testing is an essential step in the development process to ensure the correctness and performance of your Edge Functions.

Testing in Deno

Deno has a built-in test runner that you can use for testing JavaScript or TypeScript code. You can read the official documentation for more information and details about the available testing functions.

Folder structure

We recommend creating your testing in a supabase/functions/tests directory, using the same name as the Function followed by -test.ts:

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└── supabase    ├── functions    │   ├── function-one    │   │   └── index.ts    │   └── function-two    │   │   └── index.ts    │   └── tests    │       └── function-one-test.ts  # Tests for function-one    │       └── function-two-test.ts  # Tests for function-two    └── config.toml

Example script

The following script is a good example to get started with testing your Edge Functions:

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// Import required libraries and modulesimport { assert, assertEquals } from 'https://deno.land/std@0.192.0/testing/asserts.ts'import { createClient, SupabaseClient } from 'jsr:@supabase/supabase-js@2'// Will load the .env file to Deno.envimport 'https://deno.land/x/dotenv@v3.2.2/load.ts'// Set up the configuration for the Supabase clientconst supabaseUrl = Deno.env.get('SUPABASE_URL') ?? ''const supabaseKey = Deno.env.get('SUPABASE_ANON_KEY') ?? ''const options = {  auth: {    autoRefreshToken: false,    persistSession: false,    detectSessionInUrl: false,  },}// Test the creation and functionality of the Supabase clientconst testClientCreation = async () => {  var client: SupabaseClient = createClient(supabaseUrl, supabaseKey, options)  // Verify if the Supabase URL and key are provided  if (!supabaseUrl) throw new Error('supabaseUrl is required.')  if (!supabaseKey) throw new Error('supabaseKey is required.')  // Test a simple query to the database  const { data: table_data, error: table_error } = await client    .from('my_table')    .select('*')    .limit(1)  if (table_error) {    throw new Error('Invalid Supabase client: ' + table_error.message)  }  assert(table_data, 'Data should be returned from the query.')}// Test the 'hello-world' functionconst testHelloWorld = async () => {  var client: SupabaseClient = createClient(supabaseUrl, supabaseKey, options)  // Invoke the 'hello-world' function with a parameter  const { data: func_data, error: func_error } = await client.functions.invoke('hello-world', {    body: { name: 'bar' },  })  // Check for errors from the function invocation  if (func_error) {    throw new Error('Invalid response: ' + func_error.message)  }  // Log the response from the function  console.log(JSON.stringify(func_data, null, 2))  // Assert that the function returned the expected result  assertEquals(func_data.message, 'Hello bar!')}// Register and run the testsDeno.test('Client Creation Test', testClientCreation)Deno.test('Hello-world Function Test', testHelloWorld)

This test case consists of two parts. The first part tests the client library and verifies that the database can be connected to and returns values from a table (my_table). The second part tests the edge function and checks if the received value matches the expected value. Here's a brief overview of the code:

  • We import various testing functions from the Deno standard library, including assert, assertExists, and assertEquals.
  • We import the createClient and SupabaseClient classes from the @supabase/supabase-js library to interact with the Supabase client.
  • We define the necessary configuration for the Supabase client, including the Supabase URL, API key, and authentication options.
  • The testClientCreation function tests the creation of a Supabase client instance and queries the database for data from a table. It verifies that data is returned from the query.
  • The testHelloWorld function tests the "Hello-world" Edge Function by invoking it using the Supabase client's functions.invoke method. It checks if the response message matches the expected greeting.
  • We run the tests using the Deno.test function, providing a descriptive name for each test case and the corresponding test function.

Running Edge Functions locally

To locally test and debug Edge Functions, you can utilize the Supabase CLI. Let's explore how to run Edge Functions locally using the Supabase CLI:

  1. Ensure that the Supabase server is running by executing the following command:

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    supabase start

  2. In your terminal, use the following command to serve the Edge Functions locally:

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    supabase functions serve

    This command starts a local server that runs your Edge Functions, enabling you to test and debug them in a development environment.

  3. Create the environment variables file:

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    # creates the filetouch .env# adds the SUPABASE_URL secretecho "SUPABASE_URL=http://localhost:54321" >> .env# adds the SUPABASE_ANON_KEY secretecho "SUPABASE_ANON_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZS1kZW1vIiwicm9sZSI6ImFub24iLCJleHAiOjE5ODM4MTI5OTZ9.CRXP1A7WOeoJeXxjNni43kdQwgnWNReilDMblYTn_I0" >> .env# Alternatively, you can open it in your editor:open .env

  4. To run the tests, use the following command in your terminal:

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    deno test --allow-all supabase/functions/tests/function-one-test.ts

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