v1.6.0 — Major Feature Release: PostgreSQL Extensions, LSP Server & Developer Tools

This release represents a major milestone with 20+ PRs merged, adding comprehensive PostgreSQL support, a full Language Server Protocol implementation, VSCode extension, and significant performance optimizations.

Highlights#

• PostgreSQL Extensions: LATERAL JOIN, JSON/JSONB operators, DISTINCT ON, FILTER clause, aggregate ORDER BY
• Language Server Protocol: Full LSP server for IDE integration with real-time diagnostics
• VSCode Extension: Official extension with syntax highlighting, formatting, and autocomplete
• Performance: 14x faster token type checking, 575x faster keyword suggestions with caching
• Developer Experience: go-task build system, 10 linter rules, structured error codes

Added - PostgreSQL Features (PRs #173-#177)#

LATERAL JOIN Support (#173)#

• Added Lateral bool field to TableReference AST node
• Parser recognizes LATERAL in FROM and JOIN clauses
• Supports: LEFT JOIN LATERAL, INNER JOIN LATERAL, CROSS JOIN LATERAL
• CLI formatter properly outputs LATERAL keyword

ORDER BY inside Aggregates (#174)#

• Added OrderBy []OrderByExpression field to FunctionCall AST
• Supports: STRING_AGG, ARRAY_AGG, JSON_AGG, JSONB_AGG, XMLAGG, GROUP_CONCAT
• Full modifier support: ASC/DESC, NULLS FIRST/LAST
• Works with window functions and complex expressions

JSON/JSONB Operators (#175)#

• Arrow operators: ->, ->> (field access)
• Path operators: #>, #>> (path access)
• Containment: @>, <@ (contains/contained by)
• Existence: ?, ?|, ?& (key existence checks)
• Delete: #- (delete at path)
• Proper operator precedence in expression parsing
• Supports chained operators: data -> 'a' -> 'b' ->> 'c'

PostgreSQL DISTINCT ON (#171, PR #176)#

• SELECT DISTINCT ON (column1, column2) ... syntax
• Multi-column expression support
• 8 comprehensive test cases

FILTER Clause (SQL:2003 T612, PR #176)#

• COUNT(*) FILTER (WHERE condition) syntax
• Works with all aggregate functions
• 13 test cases covering edge cases

RETURNING Clause (#159, PR #164)#

• PostgreSQL-style RETURNING for INSERT, UPDATE, DELETE
• Supports: column names, *, qualified names, expressions
• Added TokenTypeReturning (379) for RETURNING keyword

Added - Language Server Protocol (PRs #128-#129)#

LSP Server Implementation (CLI-009)#

• JSON-RPC 2.0 protocol handler over stdio
• textDocument/didOpen, textDocument/didChange, textDocument/didClose - Document sync
• textDocument/publishDiagnostics - Real-time SQL syntax error reporting
• textDocument/hover - Keyword/function documentation (60+ keywords)
• textDocument/completion - SQL autocomplete (100+ keywords, 22 snippets)
• textDocument/formatting - SQL code formatting
• textDocument/documentSymbol - SQL statement outline navigation
• textDocument/signatureHelp - Function signatures (20+ SQL functions)
• textDocument/codeAction - Quick fixes (add semicolon, uppercase keywords)
• Rate limiting (100 req/sec), content size limits (10MB), document limits (5MB)
• Incremental document sync for better performance with large files
• Error position extraction from parser messages

Usage#

gosqlx lsp              # Start LSP server on stdio
gosqlx lsp --log /tmp/lsp.log  # With debug logging

Added - VSCode Extension (PRs #132, #135)#

Official GoSQLX Extension#

• Real-time SQL validation via LSP
• SQL syntax highlighting with comprehensive TextMate grammar
• SQL formatting with customizable options
• Intelligent autocomplete for SQL keywords and functions
• Hover documentation for SQL keywords
• Multi-dialect support (PostgreSQL, MySQL, SQL Server, Oracle, SQLite)

Commands#

• GoSQLX: Validate SQL
• GoSQLX: Format SQL
• GoSQLX: Analyze SQL
• GoSQLX: Restart Language Server

Settings#

• gosqlx.enable: Enable/disable language server
• gosqlx.executablePath: Path to gosqlx binary
• gosqlx.format.indentSize: Formatting indent size
• gosqlx.format.uppercaseKeywords: Uppercase SQL keywords
• gosqlx.dialect: SQL dialect selection

Added - SQL Standards Compliance (PRs #124-#126)#

Token Type Unification (ARCH-002, PR #124)#

• 120+ new SQL token types with proper categorization
• Helper methods: IsKeyword(), IsOperator(), IsLiteral(), IsDMLKeyword(), IsDDLKeyword(), IsJoinKeyword(), IsWindowKeyword(), IsAggregateFunction(), IsDataType(), IsConstraint(), IsSetOperation()
• ModelType field for O(1) int-based comparisons
• 14x faster token type checking (0.28ns vs 4.9ns)
• Token range constants for category boundaries

FETCH FIRST / OFFSET-FETCH (SQL-99 F861, F862, PR #125)#

• FETCH FIRST n ROWS ONLY / FETCH NEXT n ROWS ONLY
• FETCH FIRST n ROWS WITH TIES (preserves ties in sort order)
• FETCH FIRST n PERCENT ROWS ONLY (percentage-based limiting)
• OFFSET n ROWS combined with FETCH clause
• Added FetchClause AST node

TRUNCATE TABLE (SQL:2008, PR #126)#

• Basic syntax: TRUNCATE [TABLE] table_name
• Multiple tables: TRUNCATE TABLE t1, t2, t3
• Identity behavior: RESTART IDENTITY / CONTINUE IDENTITY
• Cascade behavior: CASCADE / RESTRICT
• Added TruncateStatement AST node

MATERIALIZED CTE Support (PR #129)#

• WITH cte AS MATERIALIZED (...) syntax
• WITH cte AS NOT MATERIALIZED (...) syntax
• PostgreSQL-compatible optimization hints

Added - Parser Enhancements (PRs #162-#164, #176)#

Column Constraints (PR #163, #146)#

• Column constraints: PRIMARY KEY, NOT NULL, NULL, UNIQUE, DEFAULT, CHECK, REFERENCES, AUTO_INCREMENT
• Table-level constraints: PRIMARY KEY, FOREIGN KEY, UNIQUE, CHECK with CONSTRAINT name
• Parameterized types: VARCHAR(100), DECIMAL(10,2), CHAR(50)
• Referential actions: ON DELETE/UPDATE CASCADE, SET NULL, SET DEFAULT, RESTRICT, NO ACTION

Derived Tables / Subqueries in FROM (#148, PR #163)#

• (SELECT ...) AS alias in FROM clause
• Support in JOIN clauses
• Full nested subquery support

Column Aliases with AS Keyword (#160, PR #163)#

• Added AliasedExpression AST type
• Preserves AS keyword in formatted output

Function Calls in INSERT VALUES (#158, PR #163)#

• NOW(), UUID(), CONCAT(), arithmetic expressions in VALUES
• Expression-based VALUES parsing

Parser Bug Fixes (PR #162)#

• #142 DISTINCT/ALL keyword support in SELECT
• #143 Arithmetic expression operator precedence (+, -, *, /, %)
• #144 SQL comments: line (--) and block (/* */)
• #145 Double-quoted identifiers: "column_name"
• #147 NATURAL JOIN, NATURAL LEFT/RIGHT JOIN
• #150 String literal quoting with single quotes
• #151 IS NULL / IS NOT NULL formatting
• #152 BETWEEN expression formatting
• #153 IN expression formatting
• #157 Qualified asterisk: table.* syntax

Added - Linter Rules (PRs #164, #176)#

10 Complete Lint Rules#

Added - Security Scanner (PRs #164, #176)#

CLI Integration (#154)#

• Integrated pkg/sql/security scanner into CLI analyzer
• Security score adjustments based on finding severity
• 100% detection rate on injection patterns

Detection Patterns#

• Tautology patterns ('1'='1', OR 1=1)
• UNION-based injection
• Time-based blind injection (SLEEP, WAITFOR DELAY)
• Comment bypass (--, /**/)
• Stacked queries
• Dangerous functions (xp_cmdshell, LOAD_FILE)

Added - Developer Tools (PRs #131, #133, #136)#

go-task Build System (PR #131)#

• Replaced Makefile with comprehensive Taskfile.yml (420+ lines)
• 45+ tasks vs original 10 Makefile targets
• Task namespacing: build:cli, test:race, lint:fix
• Cross-platform builds (linux, darwin, windows / amd64, arm64)
• CPU and memory profiling support
• Fuzz testing integration
• Security scanning (govulncheck)
• Development watch mode

Structured Error Codes (PR #133)#

• Tokenizer errors: E1001-E1005
• Parser errors: E2001-E2012
• Semantic errors: E3001-E3004 (UndefinedTable, UndefinedColumn, TypeMismatch, AmbiguousColumn)
• All errors include: error codes, location info, helpful hints, doc links
• CLI JSON output includes Code field

Unified Configuration Package (PR #133)#

• pkg/config/ with Config struct
• File and environment loaders
• LSP integration
• 78.6% test coverage

Caching System (PR #136)#

• Keyword suggestion cache: 575x speedup (12.87ns vs 7402ns)
• Config file cache: 22.5x speedup (1302ns vs 29379ns)
• Thread-safe with RWMutex
• Automatic invalidation on file modification

Added - Metrics & Monitoring (PR #129)#

Comprehensive Metrics System#

• Parser operation metrics (duration, errors, statement counts)
• AST pool metrics (gets/puts/balance)
• Statement pool metrics
• Expression pool metrics
• Tokenizer pool metrics with hit rate tracking
• Thread-safe atomic counters

Added - Test Coverage (PRs #137, #138)#

AST Test Coverage to 80%+ (PR #138)#

• DateTimeField.String() covering 44+ cases
• Parser position tracking infrastructure
• ParseWithPositions() method for position-aware parsing
• currentLocation() helper for accurate error locations

AST Interface Tests (PR #137)#

• statementNode() marker methods for all statements
• expressionNode() marker methods for all expressions
• TokenLiteral() for 60+ node types
• Children() with comprehensive branch coverage
• Coverage improved from 60.7% to 70.1%

Improved#

Performance Optimizations (PR #127)#

• O(1) switch dispatch on ModelType instead of O(n) isAnyType() calls
• isComparisonOperator() helper with O(1) ModelType switch
• Buffer pooling for keyword conversion (sync.Pool)
• ASCII fast-path in skipWhitespace for >99% of cases
• Parser pooling: GetParser/PutParser via sync.Pool
• CPU-scaled sustained load tests

AST Pool Architecture (PR #129)#

• Iterative cleanup with work queue pattern to prevent stack overflow
• Added 8 new expression pools (Exists, Any, All, List, Unary, Extract, Position, Substring)
• MaxCleanupDepth and MaxWorkQueueSize limits

Type Assertion Safety (PR #129)#

• Added proper ok pattern checking in alter.go and value.go

Race Condition Fixes (PR #129)#

• Fixed data races in metrics.go using atomic operations
• Fixed race condition in LSP documents.go with defensive copy
• Fixed race condition in watch.go with RWMutex protection

Documentation Cleanup (PR #141)#

• Deleted 4 LLM-generated files (~1,725 lines)
• Fixed API_REFERENCE.md return types
• Added 10 missing error codes to ERROR_CODES.md
• Fixed 50+ broken links and inaccurate references

Changed#

Go Version Update (PR #140)#

• Minimum requirement: Go 1.21+ (was 1.19)
• Toolchain: Go 1.21+
• Updated all CI/CD workflows to test against Go 1.21+
• golangci-lint upgraded to v2.6.2

CLI Output Improvements (PR #163)#

• Output file flag (-o) now functional for lint and analyze commands
• MERGE statement formatter with full clause support

Fixed#

• Critical type assertion panics in ALTER and VALUE parsing (PR #129)
• Race conditions in concurrent document management (PR #129)
• LSP hover returning nil instead of empty response (PR #129)
• Tokenizer negative column numbers in toSQLPosition (PR #129)
• L004 indentation depth display for depth > 9 (PR #164)
• CAST keyword missing from tokenizer keywordTokenTypes map (PR #176)
• || operator test with correct TokenTypeSingleQuotedString (PR #176)

Known Issues (Future Enhancements)#

The following features were identified during real-world testing and are tracked for future releases:

• #178: PostgreSQL JSONB existence operators (?, ?|, ?&) in parser
• #179: Multi-row INSERT VALUES syntax
• #180: BETWEEN with complex expression bounds
• #181: Tuple expressions in IN clause
• #182: PostgreSQL ARRAY constructor syntax
• #183: WITHIN GROUP ordered set aggregates