app/node_modules/langsmith/dist/utils/jestlike/matchers.js

// Levenshtein distance implementation
function levenshteinDistance(a, b) {
    if (a.length === 0)
        return b.length;
    if (b.length === 0)
        return a.length;
    const matrix = Array(b.length + 1)
        .fill(null)
        .map(() => Array(a.length + 1).fill(null));
    for (let i = 0; i <= a.length; i++)
        matrix[0][i] = i;
    for (let j = 0; j <= b.length; j++)
        matrix[j][0] = j;
    for (let j = 1; j <= b.length; j++) {
        for (let i = 1; i <= a.length; i++) {
            const substitutionCost = a[i - 1] === b[j - 1] ? 0 : 1;
            matrix[j][i] = Math.min(matrix[j][i - 1] + 1, matrix[j - 1][i] + 1, matrix[j - 1][i - 1] + substitutionCost);
        }
    }
    return matrix[b.length][a.length];
}
export async function toBeRelativeCloseTo(received, expected, options = {}) {
    const { threshold = 0.1, algorithm = "levenshtein" } = options;
    if (threshold < 0 || threshold > 1) {
        throw new Error("Relative distance is normalized, and threshold must be between 0 and 1.");
    }
    let distance;
    let maxLength;
    switch (algorithm) {
        case "levenshtein":
            distance = levenshteinDistance(received, expected);
            maxLength = Math.max(received.length, expected.length);
            break;
        default:
            throw new Error(`Unsupported algorithm: ${algorithm}`);
    }
    // Calculate relative distance (normalized between 0 and 1)
    const relativeDistance = maxLength === 0 ? 0 : distance / maxLength;
    const pass = relativeDistance <= threshold;
    return {
        pass,
        message: () => pass
            ? `Expected "${received}" not to be relatively close to "${expected}" (threshold: ${threshold}, actual distance: ${relativeDistance})`
            : `Expected "${received}" to be relatively close to "${expected}" (threshold: ${threshold}, actual distance: ${relativeDistance})`,
    };
}
export async function toBeAbsoluteCloseTo(received, expected, options = {}) {
    const { threshold = 3, algorithm = "levenshtein" } = options;
    let distance;
    switch (algorithm) {
        case "levenshtein":
            distance = levenshteinDistance(received, expected);
            break;
        default:
            throw new Error(`Unsupported algorithm: ${algorithm}`);
    }
    const pass = distance <= threshold;
    return {
        pass,
        message: () => pass
            ? `Expected "${received}" not to be absolutely close to "${expected}" (threshold: ${threshold}, actual distance: ${distance})`
            : `Expected "${received}" to be absolutely close to "${expected}" (threshold: ${threshold}, actual distance: ${distance})`,
    };
}
export async function toBeSemanticCloseTo(received, expected, options) {
    const { threshold = 0.2, embeddings, algorithm = "cosine" } = options;
    // Get embeddings for both strings
    const [receivedEmbedding, expectedEmbedding] = await Promise.all([
        embeddings.embedQuery(received),
        embeddings.embedQuery(expected),
    ]);
    // Calculate similarity based on chosen algorithm
    let similarity;
    switch (algorithm) {
        case "cosine": {
            // Compute cosine similarity
            const dotProduct = receivedEmbedding.reduce((sum, a, i) => sum + a * expectedEmbedding[i], 0);
            const receivedMagnitude = Math.sqrt(receivedEmbedding.reduce((sum, a) => sum + a * a, 0));
            const expectedMagnitude = Math.sqrt(expectedEmbedding.reduce((sum, a) => sum + a * a, 0));
            similarity = dotProduct / (receivedMagnitude * expectedMagnitude);
            break;
        }
        case "dot-product": {
            // Compute dot product similarity
            similarity = receivedEmbedding.reduce((sum, a, i) => sum + a * expectedEmbedding[i], 0);
            break;
        }
        default:
            throw new Error(`Unsupported algorithm: ${algorithm}`);
    }
    const pass = similarity >= 1 - threshold;
    return {
        pass,
        message: () => pass
            ? `Expected "${received}" not to be semantically close to "${expected}" (threshold: ${threshold}, similarity: ${similarity})`
            : `Expected "${received}" to be semantically close to "${expected}" (threshold: ${threshold}, similarity: ${similarity})`,
    };
}