Handling Errors

When you send a script to execute via freestyle.serverless.runs.create(), the script might contain invalid code that fails to parse, or it might encounter an error while running. The SDK throws typed errors for each case so you can handle them appropriately:

Syntax errors occur when your script has invalid JavaScript or TypeScript that can't be parsed
Runtime errors occur when your script executes but throws an uncaught exception

Error Types

Import the Errors namespace from the SDK to access error classes:

import { freestyle, Errors } from "freestyle-sandboxes";

Syntax Errors

A SyntaxErrorError is thrown when your script contains invalid JavaScript or TypeScript syntax. The error is detected before execution begins.

try {
  await freestyle.serverless.runs.create({
    code: `export default () z`,  // Invalid syntax
  });
} catch (error) {
  if (error instanceof Errors.SyntaxErrorError) {
    console.log("Syntax error:", error.message);
  }
}

Runtime Errors

A RuntimeErrorError is thrown when your script fails during execution. This includes uncaught exceptions, failed assertions, or any error thrown by your code.

try {
  await freestyle.serverless.runs.create({
    code: `
      export default () => {
        throw new Error("Something went wrong");
      }
    `,
  });
} catch (error) {
  if (error instanceof Errors.RuntimeErrorError) {
    console.log("Runtime error:", error.message);
    console.log("Stack trace:", error.body.stack);
  }
}

Runtime errors include any logs captured before the error occurred:

try {
  await freestyle.serverless.runs.create({
    code: `
      export default () => {
        console.log("Starting...");
        console.log("Processing data...");
        throw new Error("Failed to process");
      }
    `,
  });
} catch (error) {
  if (error instanceof Errors.RuntimeErrorError) {
    // Logs captured before the error
    for (const log of error.body.logs) {
      console.log(`[${log.type}] ${log.message}`);
    }
  }
}

Error Properties

SyntaxErrorError

Property	Type	Description
`message`	`string`	The full error message
`body.message`	`string`	The syntax error details

RuntimeErrorError

Property	Type	Description
`message`	`string`	The full error message
`body.message`	`string`	The runtime error details
`body.stack`	`string \| null`	Stack trace from the error
`body.logs`	`Array`	Logs captured before the error

Each log entry in body.logs has:

message: The log message
type: Either "log" or "error"
callstack: Optional callstack for the log