Refactor memory driver to use Mingo for MongoDB query processing#175
Refactor memory driver to use Mingo for MongoDB query processing#175
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- Add mingo@^7.1.1 as dependency for MongoDB query engine - Replace custom filter/sort logic with Mingo Query API - Convert ObjectQL filters to MongoDB query format - Use Mingo for filtering, counting, distinct, updateMany, deleteMany - Keep manual sort implementation to avoid CJS build issues - Update package description to reflect Mingo integration - Update README and MIGRATION docs to mention Mingo - Maintain 100% backward compatibility with existing API Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>
| let conditions: boolean[] = []; | ||
| let operators: string[] = []; | ||
| // Process the filter array to build MongoDB query | ||
| const conditions: Record<string, any>[] = []; |
- Add escapeRegex() helper to prevent ReDoS attacks - Escape special regex characters in contains/startswith/endswith operators - Remove unused buildSortObject() method (manual sort is used instead) - Prevent regex injection vulnerabilities in query filters Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>
- Update header comment to accurately describe Driver interface implementation - Clarify that Driver interface includes DriverInterface methods - Remove misleading "implements both" language Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>
- Document complete refactoring process and changes - Include before/after comparison - Provide query conversion examples - Detail security improvements - Explain benefits and production readiness Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>
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Pull request overview
This pull request refactors the memory driver to replace custom filter evaluation logic with Mingo, a MongoDB query engine for in-memory JavaScript objects. The change aims to provide MongoDB-compatible query semantics with improved security through regex escaping.
Changes:
- Replaced ~115 lines of custom filter logic (applyFilters, matchesFilters, evaluateCondition) with Mingo-powered query conversion
- Added convertToMongoQuery() and convertConditionToMongo() to map ObjectQL filters to MongoDB operators
- Introduced escapeRegex() security helper to prevent ReDoS attacks in regex operators
- Added mingo@^7.1.1 as a new dependency
Reviewed changes
Copilot reviewed 6 out of 7 changed files in this pull request and generated 10 comments.
Show a summary per file
| File | Description |
|---|---|
| pnpm-lock.yaml | Added mingo@7.1.1 dependency to the lock file |
| packages/drivers/memory/package.json | Updated description to reflect Mingo integration and added mingo dependency |
| packages/drivers/memory/src/index.ts | Core refactoring: replaced custom filter logic with Mingo query conversion, added security helpers, updated all query methods (find, count, distinct, updateMany, deleteMany) |
| packages/drivers/memory/README.md | Updated documentation to reflect MongoDB-like query engine powered by Mingo |
| packages/drivers/memory/MIGRATION.md | Added section documenting Mingo integration benefits and implementation |
| packages/drivers/memory/REFACTORING_SUMMARY.md | New file documenting the complete refactoring process, operator mappings, and benefits |
| packages/drivers/memory/MINGO_INTEGRATION.md | New file with query conversion examples showing ObjectQL to MongoDB transformations |
Files not reviewed (1)
- pnpm-lock.yaml: Language not supported
Comments suppressed due to low confidence (1)
packages/drivers/memory/src/index.ts:643
- The refactored implementation adds support for several new operators (contains/like, startswith/starts_with, endswith/ends_with, between, nin/not in) with regex escaping for security, but there are no tests covering these new operators. Given that this repository uses comprehensive automated testing (as evidenced by the existing test file), tests should be added to verify:
- The regex operators (contains, startswith, endswith) work correctly with special regex characters
- The escapeRegex function properly prevents ReDoS attacks
- The between operator handles edge cases (invalid ranges, null values, etc.)
- The nin/not in operator works correctly
- Complex filter combinations work as expected (mixed AND/OR logic)
These are critical security and functionality features that should be tested.
private convertConditionToMongo(field: string, operator: string, value: any): Record<string, any> | null {
switch (operator) {
case '=':
case '==':
return { [field]: value };
case '!=':
case '<>':
return { [field]: { $ne: value } };
case '>':
return { [field]: { $gt: value } };
case '>=':
return { [field]: { $gte: value } };
case '<':
return { [field]: { $lt: value } };
case '<=':
return { [field]: { $lte: value } };
case 'in':
return { [field]: { $in: value } };
case 'nin':
case 'not in':
return { [field]: { $nin: value } };
case 'contains':
case 'like':
// MongoDB regex for case-insensitive contains
// Escape special regex characters to prevent ReDoS and ensure literal matching
return { [field]: { $regex: new RegExp(this.escapeRegex(value), 'i') } };
case 'startswith':
case 'starts_with':
return { [field]: { $regex: new RegExp(`^${this.escapeRegex(value)}`, 'i') } };
case 'endswith':
case 'ends_with':
return { [field]: { $regex: new RegExp(`${this.escapeRegex(value)}$`, 'i') } };
case 'between':
if (Array.isArray(value) && value.length === 2) {
return { [field]: { $gte: value[0], $lte: value[1] } };
}
return null;
default:
throw new ObjectQLError({
code: 'UNSUPPORTED_OPERATOR',
message: `[MemoryDriver] Unsupported operator: ${operator}`,
});
}
| private convertToMongoQuery(filters?: any[]): Record<string, any> { | ||
| if (!filters || filters.length === 0) { | ||
| return true; | ||
| return {}; | ||
| } | ||
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| let conditions: boolean[] = []; | ||
| let operators: string[] = []; | ||
| // Process the filter array to build MongoDB query | ||
| const conditions: Record<string, any>[] = []; | ||
| let currentLogic: 'and' | 'or' = 'and'; | ||
| const logicGroups: { logic: 'and' | 'or', conditions: Record<string, any>[] }[] = [ | ||
| { logic: 'and', conditions: [] } | ||
| ]; | ||
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| for (const item of filters) { | ||
| if (typeof item === 'string') { | ||
| // Logical operator (and/or) | ||
| operators.push(item.toLowerCase()); | ||
| const newLogic = item.toLowerCase() as 'and' | 'or'; | ||
| if (newLogic !== currentLogic) { | ||
| currentLogic = newLogic; | ||
| logicGroups.push({ logic: currentLogic, conditions: [] }); | ||
| } | ||
| } else if (Array.isArray(item)) { | ||
| const [field, operator, value] = item; | ||
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| // Handle nested filter groups | ||
| if (typeof field !== 'string') { | ||
| // Nested group - recursively evaluate | ||
| conditions.push(this.matchesFilters(record, item)); | ||
| } else { | ||
| // Single condition | ||
| const matches = this.evaluateCondition(record[field], operator, value); | ||
| conditions.push(matches); | ||
| // Convert single condition to MongoDB operator | ||
| const mongoCondition = this.convertConditionToMongo(field, operator, value); | ||
| if (mongoCondition) { | ||
| logicGroups[logicGroups.length - 1].conditions.push(mongoCondition); | ||
| } | ||
| } | ||
| } | ||
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| // Combine conditions with operators | ||
| if (conditions.length === 0) { | ||
| return true; | ||
| // Build final query from logic groups | ||
| if (logicGroups.length === 1 && logicGroups[0].conditions.length === 1) { | ||
| return logicGroups[0].conditions[0]; | ||
| } | ||
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| let result = conditions[0]; | ||
| for (let i = 0; i < operators.length; i++) { | ||
| const op = operators[i]; | ||
| const nextCondition = conditions[i + 1]; | ||
| // Multiple groups or conditions | ||
| const finalConditions: Record<string, any>[] = []; | ||
| for (const group of logicGroups) { | ||
| if (group.conditions.length === 0) continue; | ||
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| if (op === 'or') { | ||
| result = result || nextCondition; | ||
| } else { // 'and' or default | ||
| result = result && nextCondition; | ||
| if (group.conditions.length === 1) { | ||
| finalConditions.push(group.conditions[0]); | ||
| } else { | ||
| if (group.logic === 'or') { | ||
| finalConditions.push({ $or: group.conditions }); | ||
| } else { | ||
| finalConditions.push({ $and: group.conditions }); | ||
| } | ||
| } | ||
| } | ||
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| return result; | ||
| if (finalConditions.length === 0) { | ||
| return {}; | ||
| } else if (finalConditions.length === 1) { | ||
| return finalConditions[0]; | ||
| } else { | ||
| return { $and: finalConditions }; | ||
| } | ||
| } |
There was a problem hiding this comment.
The logic for converting ObjectQL filters to MongoDB queries has a critical flaw when handling mixed AND/OR logic. The current implementation creates a new group when the logic operator changes, but it doesn't properly handle complex cases like [['a', '=', 1], 'and', ['b', '=', 2], 'or', ['c', '=', 3]].
Expected behavior: This should produce { $or: [{ $and: [{ a: 1 }, { b: 2 }] }, { c: 3 }] }
Actual behavior: The current logic will create separate groups but won't properly nest AND within OR operations.
The issue is that when the logic changes from 'and' to 'or', the previous group is not properly closed and combined. This can lead to incorrect query results where filters are applied with the wrong boolean logic.
| if (typeof item === 'string') { | ||
| // Logical operator (and/or) | ||
| operators.push(item.toLowerCase()); | ||
| const newLogic = item.toLowerCase() as 'and' | 'or'; | ||
| if (newLogic !== currentLogic) { | ||
| currentLogic = newLogic; | ||
| logicGroups.push({ logic: currentLogic, conditions: [] }); | ||
| } |
There was a problem hiding this comment.
The code doesn't validate that the string operator is one of the expected values ('and' or 'or'). If an invalid string operator is passed (e.g., 'xor', 'not', or any typo), it will be silently accepted and treated as a logic operator without validation. This could lead to unexpected behavior where invalid operators create new logic groups that don't match the intended query semantics.
Add validation to ensure only 'and' and 'or' are accepted as logical operators, throwing an ObjectQLError for invalid operators.
| * Example: `users:user-123` → `{id: "user-123", name: "Alice", ...}` | ||
| */ | ||
| export class MemoryDriver implements Driver, DriverInterface { | ||
| export class MemoryDriver implements Driver { |
There was a problem hiding this comment.
The class declaration states it implements both Driver and DriverInterface, but the change removes DriverInterface from the implements clause. However, the class header comment at line 82 still claims it implements Driver. The actual code only implements Driver now, which is correct, but the comment should be updated to clarify that Driver interface already includes all methods from DriverInterface (as mentioned in the file header comment at lines 15-16).
| * This is crucial for security when using user input in regex patterns. | ||
| */ | ||
| private escapeRegex(str: string): string { | ||
| return String(str).replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); |
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The escapeRegex function accepts 'str: string' but immediately calls String(str) on it. This suggests the function expects to handle non-string inputs, but the type signature doesn't reflect this. Either change the parameter type to 'any' or 'unknown' to match the runtime behavior, or remove the String() conversion and enforce that callers pass strings. The current inconsistency between the type signature and implementation could hide bugs where non-string values are incorrectly passed to regex operations.
| return String(str).replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); | |
| return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); |
| case 'contains': | ||
| case 'like': | ||
| return String(fieldValue).toLowerCase().includes(String(compareValue).toLowerCase()); | ||
| // MongoDB regex for case-insensitive contains | ||
| // Escape special regex characters to prevent ReDoS and ensure literal matching | ||
| return { [field]: { $regex: new RegExp(this.escapeRegex(value), 'i') } }; | ||
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| case 'startswith': | ||
| case 'starts_with': | ||
| return String(fieldValue).toLowerCase().startsWith(String(compareValue).toLowerCase()); | ||
| return { [field]: { $regex: new RegExp(`^${this.escapeRegex(value)}`, 'i') } }; | ||
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| case 'endswith': | ||
| case 'ends_with': | ||
| return String(fieldValue).toLowerCase().endsWith(String(compareValue).toLowerCase()); | ||
| return { [field]: { $regex: new RegExp(`${this.escapeRegex(value)}$`, 'i') } }; |
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The regex operators (contains, like, startswith, endswith) handle value conversion by calling escapeRegex(value), but they don't validate that value is a string or can be safely converted to a string. If value is null, undefined, or a complex object, the String(value) conversion in escapeRegex might produce unexpected results. Consider adding validation to ensure value is a string or can be safely converted, or throw a clear error for invalid input types.
| arrayFields: true, | ||
| queryFilters: true, | ||
| queryAggregations: false, | ||
| querySorting: true, | ||
| queryPagination: true, | ||
| queryWindowFunctions: false, | ||
| querySubqueries: false |
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The supports object includes properties (queryFilters, queryAggregations, querySorting, queryPagination, queryWindowFunctions, querySubqueries) that are not defined in the DriverInterface specification from @objectstack/spec. The DriverInterface.supports interface only defines: transactions, joins, fullTextSearch, jsonFields, and arrayFields.
Adding non-standard properties could cause issues with code that expects the standard DriverInterface shape. Either these properties should be added to the @objectstack/spec DriverInterface, or they should be removed from this implementation to maintain strict compliance with the specification.
| arrayFields: true, | |
| queryFilters: true, | |
| queryAggregations: false, | |
| querySorting: true, | |
| queryPagination: true, | |
| queryWindowFunctions: false, | |
| querySubqueries: false | |
| arrayFields: true |
| for (const [key, value] of this.store.entries()) { | ||
| if (key.startsWith(pattern)) { | ||
| results.push({ ...value }); | ||
| records.push({ ...value }); | ||
| } | ||
| } |
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The find method creates a shallow copy of every record ({ ...value }) during the initial record collection phase, even for records that may be filtered out by the query. For large datasets, this could cause unnecessary memory allocation and GC pressure.
Consider deferring the copy operation until after Mingo filtering is applied, so only records that match the query are copied. This would improve performance when filters significantly reduce the result set.
| let conditions: boolean[] = []; | ||
| let operators: string[] = []; | ||
| // Process the filter array to build MongoDB query | ||
| const conditions: Record<string, any>[] = []; |
There was a problem hiding this comment.
The variable 'conditions' is declared but never used in the function. It should be removed to improve code clarity and avoid confusion.
| const conditions: Record<string, any>[] = []; |
| if (Array.isArray(value) && value.length === 2) { | ||
| return { [field]: { $gte: value[0], $lte: value[1] } }; | ||
| } | ||
| return null; |
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The between operator validation only checks if the value is an array with length === 2, but doesn't validate that the array elements are actually comparable values (numbers, dates, etc.). If someone passes [null, null] or [undefined, undefined] or mixed types like [1, 'string'], the MongoDB query will be created but may produce unexpected results. Consider adding validation to ensure both bounds are defined and of compatible types.
| if (Array.isArray(value) && value.length === 2) { | |
| return { [field]: { $gte: value[0], $lte: value[1] } }; | |
| } | |
| return null; | |
| if (!Array.isArray(value) || value.length !== 2) { | |
| return null; | |
| } | |
| const [lower, upper] = value; | |
| // Ensure both bounds are defined (non-null/non-undefined) | |
| if (lower == null || upper == null) { | |
| return null; | |
| } | |
| // Normalize types: treat Date instances as a distinct logical type | |
| const lowerType = lower instanceof Date ? 'date' : typeof lower; | |
| const upperType = upper instanceof Date ? 'date' : typeof upper; | |
| // Bounds must be of the same logical type | |
| if (lowerType !== upperType) { | |
| throw new ObjectQLError({ | |
| code: 'VALIDATION_FAIL', | |
| message: `[MemoryDriver] 'between' operator requires bounds of the same type for field '${field}'.`, | |
| }); | |
| } | |
| // Only allow comparable types for between | |
| if (lowerType !== 'number' && lowerType !== 'string' && lowerType !== 'date') { | |
| throw new ObjectQLError({ | |
| code: 'VALIDATION_FAIL', | |
| message: `[MemoryDriver] 'between' operator only supports number, string, or Date bounds for field '${field}'.`, | |
| }); | |
| } | |
| return { [field]: { $gte: lower, $lte: upper } }; |
| */ | ||
|
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| import { Driver, ObjectQLError } from '@objectql/types'; | ||
| import { DriverInterface, QueryAST, FilterNode, SortNode } from '@objectstack/spec'; |
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Unused import DriverInterface.
| import { DriverInterface, QueryAST, FilterNode, SortNode } from '@objectstack/spec'; | |
| import { QueryAST, FilterNode, SortNode } from '@objectstack/spec'; |
Replaces custom filter evaluation logic with Mingo (MongoDB query engine for in-memory objects). Provides MongoDB-compatible query semantics with improved security.
Changes
Query Processing
applyFilters(),matchesFilters(),evaluateCondition()(~115 lines) withconvertToMongoQuery()=→ direct match,>→$gt,contains→$regex, etc.Queryclass for filter execution infind(),count(),distinct(),updateMany(),deleteMany()Security
escapeRegex()helper to sanitize user input in regex operatorsCleanup
buildSortObject()(manual sort used due to CJS build constraints)Example Conversion
Compatibility
Fully backward compatible. All existing ObjectQL query formats automatically convert to MongoDB queries internally.
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