Module error

Error handling and execution reporting utilities.

Provides utilities for error handling, message formatting, and execution timing to support error reporting and performance analysis.

Type Guard Assertion

Validate values against type guards with automatic error messages:

import { assert } from '@metreeca/core/error';
import { isString, isNumber } from '@metreeca/core';

const name = assert(input, isString);  // throws TypeError if not a string
const count = assert(data, isNumber, "count must be numeric");
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Error Throwing in Expressions

Throw errors in expression contexts where statements aren't allowed:

import { error } from '@metreeca/core/error';

const value = map.get(key) ?? error("Missing required key");

const result = isValid(input)
  ? processInput(input)
  : error(new ValidationError("Invalid input"));
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Message Formatting

Extract readable messages from various value types:

import { message } from '@metreeca/core/error';

console.error(`Failed with: ${message(errorValue)}`);

// Error objects -> message property
// Numbers -> locale-formatted strings
// Other values -> string representation
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Execution Timing

Monitor timing for synchronous and asynchronous operations:

import { time } from '@metreeca/core/error';

const result = await time(
  async () => fetchData(url),
  (data, elapsed) => console.log(`Fetched in ${elapsed}ms`)
);

const computed = time(
  () => expensiveCalculation(),
  (result, elapsed) => logPerformance('calculation', elapsed)
);
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