| 8 | 8 | * @returns {Promise<Object.<string, number>>} |
| 9 | 9 | */ |
| 10 | 10 | export const parallelLetterFrequency = async (texts) => { |
| 11 | | throw new Error('Remove this line and implement the function'); |
| 11 | // Edge Case: Handle null or undefined input |
| 12 | if (texts === null || texts === undefined) { |
| 13 | return {}; |
| 14 | } |
| 15 | |
| 16 | // Edge Case: Handle empty array input |
| 17 | if (texts.length === 0) { |
| 18 | return {}; |
| 19 | } |
| 20 | |
| 21 | // Create an array of promises for counting letters in each text |
| 22 | const promises = texts.map(text => { |
| 23 | return new Promise((resolve) => { |
| 24 | // Edge Case: Handle null or undefined text elements |
| 25 | if (text === null || text === undefined) { |
| 26 | resolve({}); |
| 27 | return; |
| 28 | } |
| 29 | |
| 30 | const letterCount = {}; |
| 31 | // Convert to lowercase and process each character |
| 32 | for (const char of text.toLowerCase()) { |
| 33 | // Edge Case: Only count alphabetic characters |
| 34 | if (char >= 'a' && char <= 'z') { |
| 35 | letterCount[char] = (letterCount[char] || 0) + 1; |
| 36 | } |
| 37 | } |
| 38 | resolve(letterCount); |
| 39 | }); |
| 40 | }); |
| 41 | |
| 42 | // Wait for all promises to complete |
| 43 | const results = await Promise.all(promises); |
| 44 | |
| 45 | // Combine all results into a single frequency object |
| 46 | const finalCount = {}; |
| 47 | |
| 48 | // Edge Case: Handle empty results array |
| 49 | if (results.length === 0) { |
| 50 | return finalCount; |
| 51 | } |
| 52 | |
| 53 | for (const result of results) { |
| 54 | for (const [letter, count] of Object.entries(result)) { |
| 55 | finalCount[letter] = (finalCount[letter] || 0) + count; |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | return finalCount; |
| 12 | 60 | }; |
| 61 | |
| 62 | // Handled Edge Cases: null/undefined input, empty array, null/undefined text elements, non-alphabetic characters, empty results |