These are the docs for the beta version of Evalite. Install with pnpm add evalite@beta

exactMatch

Checks if your AI’s output exactly matches the expected text character-for-character. Returns 1 if they match, 0 otherwise.

When to use: For testing structured outputs like JSON, code, or specific phrases that must be exact.

When NOT to use: When slight variations in wording are acceptable (use answerSimilarity instead).

Example

import { evalite } from "evalite";
import { exactMatch } from "evalite/scorers/deterministic";

evalite("Exact Match", {
  data: [
    {
      input: "What is the capital of France?",
      expected: {
        reference: "Paris is the capital of France",
      },
    },
  ],
  task: async (input) => {
    return "Paris is the capital of France";
  },
  scorers: [
    {
      scorer: ({ output, expected }) =>
        exactMatch({
          actual: output,
          expected: expected.reference,
        }),
    },
  ],
});

Signature

async function exactMatch(opts: { actual: string; expected: string }): Promise<{
  name: string;
  description: string;
  score: number;
}>;

Parameters

actual

Type: string

The actual output to check.

expected