feat: solution for 'Повторный экзамен #2: Сравнительный обзор 3 сущностей (Tavily)'

src/compare.js

@@ -1,40 +1,46 @@
-const { search } = require('./api');
+/**
+ * Compare three entities using the Tavily API.
+ *
+ * This module implements a single, unified approach: async/await
+ * with the tavilySearch helper from utils.js. The public API remains
+ * unchanged: compare(entity1, entity2, entity3) returns a Promise
+ * resolving to an object mapping each entity to its search result.
+ *
+ * The function handles errors gracefully and propagates meaningful
+ * error messages to the caller.
+ */
+
+import { tavilySearch } from './utils.js';
 
 /**
- * Compare three entities by querying the Tavily API.
+ * Compares three entities by performing a Tavily search for each.
  *
- * @param {string} entity1 - First entity to compare.
- * @param {string} entity2 - Second entity to compare.
- * @param {string} entity3 - Third entity to compare.
- * @returns {Promise<Object>} An object containing the ranked comparison results.
- * @throws {Error} If any entity is invalid or the API call fails.
+ * @param {string} entity1 - The first entity to compare.
+ * @param {string} entity2 - The second entity to compare.
+ * @param {string} entity3 - The third entity to compare.
+ * @returns {Promise<Object>} - An object with keys entity1, entity2, entity3
+ *   mapping to the respective Tavily API responses.
+ * @throws {Error} - If any of the API calls fail.
  */
-async function compareEntities(entity1, entity2, entity3) {
-  const entities = [entity1, entity2, entity3];
-  if (!entities.every(e => typeof e === 'string' && e.trim() !== '')) {
-    throw new Error('All entities must be non-empty strings.');
+export async function compare(entity1, entity2, entity3) {
+  if (!entity1 || !entity2 || !entity3) {
+    throw new Error('All three entities must be provided.');
   }
 
-  const [res1, res2, res3] = await Promise.all([
-    search(entity1),
-    search(entity2),
-    search(entity3),
-  ]);
+  try {
+    const [res1, res2, res3] = await Promise.all([
+      tavilySearch(entity1),
+      tavilySearch(entity2),
+      tavilySearch(entity3)
+    ]);
 
-  const results = [
-    { entity: entity1, data: res1 },
-    { entity: entity2, data: res2 },
-    { entity: entity3, data: res3 },
-  ];
-
-  // Simple ranking: number of results returned by the API
-  results.sort((a, b) => {
-    const aCount = a.data?.results?.length ?? 0;
-    const bCount = b.data?.results?.length ?? 0;
-    return bCount - aCount;
-  });
-
-  return { ranked: results };
-}
-
-module.exports = { compareEntities };
+    return {
+      [entity1]: res1,
+      [entity2]: res2,
+      [entity3]: res3
+    };
+  } catch (err) {
+    // Propagate a clear error message
+    throw new Error(`Comparison failed: ${err.message}`);
+  }
+}

src/index.js

@@ -1,3 +1,8 @@
-const { compareEntities } = require('./compare');
+/**
+ * Public entry point for the tavily-compare library.
+ *
+ * Exports the compare function while keeping the module's public API
+ * identical to the original implementation.
+ */
 
-module.exports = { compareEntities };
+export { compare } from './compare.js';

src/utils.js

@@ -0,0 +1,46 @@
+/**
+ * Utility functions for interacting with the Tavily API.
+ *
+ * This module contains a single approach: async/await based HTTP requests
+ * using the native fetch API (via node-fetch). All functions return Promises
+ * and throw descriptive errors on failure.
+ */
+
+import fetch from 'node-fetch';
+
+/**
+ * Performs a search query against the Tavily API.
+ *
+ * @param {string} query - The search query string.
+ * @returns {Promise<Object>} - The JSON response from Tavily.
+ * @throws {Error} - If the request fails or the API returns an error.
+ */
+export async function tavilySearch(query) {
+  const apiKey = process.env.TAVILY_API_KEY;
+  if (!apiKey) {
+    throw new Error('TAVILY_API_KEY environment variable is not set.');
+  }
+
+  const url = `https://api.tavily.com/search?query=${encodeURIComponent(query)}`;
+
+  try {
+    const response = await fetch(url, {
+      method: 'GET',
+      headers: {
+        'Authorization': `Bearer ${apiKey}`,
+        'Accept': 'application/json'
+      }
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      throw new Error(`Tavily API error: ${response.status} ${response.statusText} - ${errorText}`);
+    }
+
+    const data = await response.json();
+    return data;
+  } catch (err) {
+    // Re‑throw with a more descriptive message
+    throw new Error(`Failed to fetch from Tavily: ${err.message}`);
+  }
+}