/**
* Fuzzy Matcher
* Provides column name auto-correction using Fuse.js
* Requirements: 4.1, 4.2, 4.3, 4.4
*/
import Fuse from 'fuse.js';
/**
* Result of a column name correction operation
*/
export interface CorrectionResult {
original: string;
corrected: string;
wasChanged: boolean;
}
/**
* Result of correcting a SoQL query
*/
export interface SoqlCorrectionResult {
correctedQuery: string;
corrections: CorrectionResult[];
}
/**
* Fuzzy matcher for auto-correcting column names in SoQL queries
*/
export class FuzzyMatcher {
private threshold: number;
/**
* Create a new FuzzyMatcher
* @param threshold Fuzzy matching threshold (0-1, lower is more strict). Default: 0.4
*/
constructor(threshold: number = 0.4) {
this.threshold = threshold;
}
/**
* Correct a list of user-provided field names against valid field names
* Requirement 4.1, 4.2, 4.3, 4.4
*
* @param userFields Array of field names to correct
* @param validFields Array of valid field names from the schema
* @returns Array of correction results
*/
correctColumns(userFields: string[], validFields: string[]): CorrectionResult[] {
const fuse = new Fuse(validFields, {
threshold: this.threshold,
includeScore: true,
});
return userFields.map(original => {
const results = fuse.search(original);
// If we have a match within threshold, use it
if (results.length > 0 && results[0].score !== undefined && results[0].score <= this.threshold) {
const corrected = results[0].item;
return {
original,
corrected,
wasChanged: original !== corrected,
};
}
// No match found, pass through unchanged (Requirement 4.3)
return {
original,
corrected: original,
wasChanged: false,
};
});
}
/**
* Parse a SoQL query and correct column names
* Requirement 4.1, 4.2, 4.3, 4.4
*
* This method extracts field names from a SoQL query and corrects them
* against the valid field names from the dataset schema.
*
* @param soql The SoQL query string
* @param validFields Array of valid field names from the schema
* @returns Corrected query and list of corrections made
*/
correctSoqlQuery(soql: string, validFields: string[]): SoqlCorrectionResult {
// Extract potential field names from the SoQL query
// Field names can appear in SELECT, WHERE, ORDER BY, GROUP BY clauses
// We'll use a regex to find identifiers (alphanumeric + underscore)
const fieldPattern = /\b([a-zA-Z_][a-zA-Z0-9_]*)\b/g;
const matches = [...soql.matchAll(fieldPattern)];
// Get unique field names (excluding SQL keywords)
const sqlKeywords = new Set([
'select', 'from', 'where', 'order', 'by', 'group', 'limit', 'offset',
'and', 'or', 'not', 'in', 'like', 'between', 'is', 'null', 'as',
'asc', 'desc', 'count', 'sum', 'avg', 'min', 'max', 'distinct',
'having', 'join', 'left', 'right', 'inner', 'outer', 'on', 'case',
'when', 'then', 'else', 'end', 'true', 'false'
]);
const userFields = [...new Set(
matches
.map(m => m[1])
.filter(field => !sqlKeywords.has(field.toLowerCase()))
)];
// Get corrections for all extracted fields
const corrections = this.correctColumns(userFields, validFields);
// Build a map of corrections that were actually changed
const correctionMap = new Map<string, string>();
corrections
.filter(c => c.wasChanged)
.forEach(c => correctionMap.set(c.original, c.corrected));
// Replace field names in the query
let correctedQuery = soql;
correctionMap.forEach((corrected, original) => {
// Use word boundaries to avoid partial replacements
const regex = new RegExp(`\\b${original}\\b`, 'g');
correctedQuery = correctedQuery.replace(regex, corrected);
});
return {
correctedQuery,
corrections: corrections.filter(c => c.wasChanged), // Only return actual corrections (Requirement 4.2)
};
}
}
