/**
* Mock embeddings provider for testing
*/
import type { EmbeddingsProvider } from '../embeddings/types.js';
/**
* Creates a mock embeddings provider for testing
* @param dimensions - The number of dimensions for the embeddings (default 384 like FastEmbed)
*/
export function createMockEmbeddings(dimensions: number = 384): EmbeddingsProvider {
return {
dimensions,
embed: async (text: string): Promise<number[]> => {
// Generate deterministic embedding based on text content hash
const hash = simpleHash(text);
return generateDeterministicVector(hash, dimensions);
},
};
}
/**
* Simple hash function for generating deterministic values
*/
function simpleHash(str: string): number {
let hash = 0;
for (let i = 0; i < str.length; i++) {
const char = str.charCodeAt(i);
hash = (hash << 5) - hash + char;
hash = hash & hash; // Convert to 32bit integer
}
return Math.abs(hash);
}
/**
* Generate a deterministic vector based on a seed
*/
function generateDeterministicVector(seed: number, dimensions: number): number[] {
const vector: number[] = [];
let value = seed;
for (let i = 0; i < dimensions; i++) {
// Linear congruential generator
value = (value * 1103515245 + 12345) & 0x7fffffff;
// Normalize to [-1, 1]
vector.push((value / 0x7fffffff) * 2 - 1);
}
// Normalize vector to unit length
const magnitude = Math.sqrt(vector.reduce((sum, v) => sum + v * v, 0));
return vector.map((v) => v / magnitude);
}
/**
* Mock embeddings provider that returns zero vectors (for error testing)
*/
export function createZeroEmbeddings(dimensions: number = 384): EmbeddingsProvider {
return {
dimensions,
embed: async (): Promise<number[]> => new Array(dimensions).fill(0),
};
}
/**
* Mock embeddings provider that throws errors (for error handling testing)
*/
export function createFailingEmbeddings(dimensions: number = 384): EmbeddingsProvider {
return {
dimensions,
embed: async (): Promise<number[]> => {
throw new Error('Embeddings service unavailable');
},
};
}
