pg-proto-parser

pg-proto-parser is a TypeScript project that parses pganalyze/libpg_query PostgreSQL Protocol Buffers (protobuf) definitions and generates TypeScript interfaces, utility functions, and JSON mappings for the enums defined in the protobuf schema. Designed to work with launchql/pgsql-parser for maintainable upgrades.

Features

• Parses protobuf definitions and creates a structured representation in TypeScript.
• Generates TypeScript interfaces for protobuf messages.
• Creates utility functions for enum value conversions with multiple output formats:
  • Bidirectional conversion functions (string ↔ number)
  • Unidirectional conversion functions with precise types
  • Switch statement or nested object output formats
• Produces JSON or TypeScript files mapping enum names to integer values and vice versa
• Supports tree-shakable enum utilities for optimal bundle sizes

Parsing and Generating Files

Here's how to parse protobuf files and generate the output:

import { PgProtoParser } from 'pg-proto-parser';

// Create PgProtoParser
const parser = new PgProtoParser(inFile, { outDir });

// Generate TypeScript and JSON files
await parser.write();

pg-proto-parser will generate the following files in the specified outDir:

• types.ts: TypeScript file containing interfaces for protobuf messages.
• enums.ts: TypeScript file containing enums for protobuf messages.
• asts.ts: TypeScript file containing helpers to create PostgreSQL ASTs.
• utils.ts: TypeScript file containing utility functions for enums.
• enums2int.json: JSON mapping of enum names to integer values.
• enums2str.json: JSON mapping of integer values to enum names.

Example: Generating TypeScript Enum Maps

You can generate TypeScript exports instead of JSON files for enum mappings:

const parser = new PgProtoParser(inFile, {
  outDir,
  enums: {
    enumMap: {
      enabled: true,
      format: 'ts',  // Generate TypeScript exports
      toIntOutFile: 'enum-to-int.ts',
      toStrOutFile: 'enum-to-str.ts'
    }
  }
});

await parser.write();

This will generate TypeScript files with exports like:

// enum-to-int.ts
export const enumToIntMap = {
  OverridingKind: {
    OVERRIDING_NOT_SET: 0,
    OVERRIDING_USER_VALUE: 1,
    OVERRIDING_SYSTEM_VALUE: 2
  },
  // ... more enums
};
export type EnumToIntMap = typeof enumToIntMap;

// enum-to-str.ts
export const enumToStrMap = {
  OverridingKind: {
    "0": 'OVERRIDING_NOT_SET',
    "1": 'OVERRIDING_USER_VALUE',
    "2": 'OVERRIDING_SYSTEM_VALUE'
  },
  // ... more enums
};
export type EnumToStrMap = typeof enumToStrMap;

Example: Generating Enum Utility Functions

You can generate utility functions for runtime enum conversions:

// Bidirectional function (default)
const parser = new PgProtoParser(inFile, {
  outDir,
  utils: {
    enums: {
      enabled: true,
      filename: 'enum-utils.ts'
    }
  }
});

// Unidirectional functions with switch statements
const parser = new PgProtoParser(inFile, {
  outDir,
  utils: {
    enums: {
      enabled: true,
      unidirectional: true,
      toIntFilename: 'enum-to-int.ts',
      toStringFilename: 'enum-to-string.ts'
    }
  }
});

// Unidirectional functions with nested objects format
const parser = new PgProtoParser(inFile, {
  outDir,
  utils: {
    enums: {
      enabled: true,
      unidirectional: true,
      outputFormat: 'nestedObjects',
      toIntFilename: 'enum-to-int-map.ts',
      toStringFilename: 'enum-to-string-map.ts'
    }
  }
});

Generated Utility Functions

Bidirectional (default):

// utils.ts
export const getEnumValue = (enumType: EnumType, key: string | number) => {
  // Returns number for string input, string for number input
};

Unidirectional with switch statements:

// enum-to-int.ts
export const getEnumInt = (enumType: EnumType, key: string): number => {
  // Converts enum string to number
};

// enum-to-string.ts
export const getEnumString = (enumType: EnumType, key: number): string => {
  // Converts enum number to string
};

Unidirectional with nested objects:

// enum-to-int-map.ts
export const enumToIntMap = {
  OverridingKind: (key: string): number => { /* ... */ },
  QuerySource: (key: string): number => { /* ... */ },
  // ... more enums
};

// Usage
const value = enumToIntMap.OverridingKind("OVERRIDING_USER_VALUE"); // Returns: 1

Configuration

You can configure pg-proto-parser by passing different parameters to the ProtoStore constructor:

• root: The protobuf Root object containing your schema.
• options: Options defined as PgProtoParserOptions (see below)

Options

The options for PgProtoParserOptions are organized into the following categories:

General Options

Type Generation Options

Enum Generation Options

Enum Mapping Options

Note: The enums.json.* options are deprecated in favor of enums.enumMap.*. When using TypeScript format (format: 'ts'), the file extensions will be automatically corrected to .ts.

Utility Generation Options

Runtime Schema Options

Each of these options can be set when initializing the PgProtoParser to customize its behavior and output.

Meta AST (generateTsAstCodeFromPgAst)

generateTsAstCodeFromPgAst is a method that transforms a PostgreSQL Abstract Syntax Tree (AST) into TypeScript code capable of generating an equivalent AST. This function facilitates the dynamic creation of ASTs, allowing for programmable query construction and manipulation in TypeScript.

It generates code with syntax for @pgsql/utils, using runtime schema information to determine whether nodes should be wrapped (t.nodes.*) or unwrapped (t.ast.*).

import { generateTsAstCodeFromPgAst } from 'pg-proto-parser';
import { runtimeSchema } from './path/to/your/generated/runtime-schema';
import { parse } from 'pgsql-parser';

// Example SQL query
const sql = 'SELECT * FROM my_table WHERE id = 1';

// Parse the SQL query to get the PostgreSQL AST
const pgAst = parse(sql);

// Generate TypeScript AST builder code from the PostgreSQL AST using runtime schema
const tsAstBuilderCode = generateTsAstCodeFromPgAst(
  pgAst[0].RawStmt.stmt,
  runtimeSchema
);

console.log(tsAstBuilderCode);
// OUTPUT BELOW:
// make sure to use this import when using
// import ast from '@pgsql/utils';

t.nodes.selectStmt({
  targetList: [t.nodes.resTarget({
    val: t.nodes.columnRef({
      fields: [t.nodes.aStar({})],
      location: 7
    }),
    location: 7
  })],
  fromClause: [t.nodes.rangeVar({
    relname: "my_table",
    inh: true,
    relpersistence: "p",
    location: 14
  })],
  whereClause: t.nodes.aExpr({
    kind: "AEXPR_OP",
    name: [t.nodes.string({
      sval: "="
    })],
    lexpr: t.nodes.columnRef({
      fields: [t.nodes.string({
        sval: "id"
      })],
      location: 29
    }),
    rexpr: t.nodes.aConst({
      ival: t.ast.integer({
        ival: 1
      }),
      location: 34
    }),
    location: 32
  }),
  limitOption: "LIMIT_OPTION_DEFAULT",
  op: "SETOP_NONE"
})

Related

• pgsql-parser: The real PostgreSQL parser for Node.js, providing symmetric parsing and deparsing of SQL statements with actual PostgreSQL parser integration.
• pgsql-deparser: A streamlined tool designed for converting PostgreSQL ASTs back into SQL queries, focusing solely on deparser functionality to complement pgsql-parser.
• @pgsql/parser: Multi-version PostgreSQL parser with dynamic version selection at runtime, supporting PostgreSQL 15, 16, and 17 in a single package.
• @pgsql/types: Offers TypeScript type definitions for PostgreSQL AST nodes, facilitating type-safe construction, analysis, and manipulation of ASTs.
• @pgsql/enums: Provides TypeScript enum definitions for PostgreSQL constants, enabling type-safe usage of PostgreSQL enums and constants in your applications.
• @pgsql/utils: A comprehensive utility library for PostgreSQL, offering type-safe AST node creation and enum value conversions, simplifying the construction and manipulation of PostgreSQL ASTs.
• pg-proto-parser: A TypeScript tool that parses PostgreSQL Protocol Buffers definitions to generate TypeScript interfaces, utility functions, and JSON mappings for enums.
• libpg-query: The real PostgreSQL parser exposed for Node.js, used primarily in pgsql-parser for parsing and deparsing SQL queries.

Disclaimer

AS DESCRIBED IN THE LICENSES, THE SOFTWARE IS PROVIDED "AS IS", AT YOUR OWN RISK, AND WITHOUT WARRANTIES OF ANY KIND.

No developer or entity involved in creating Software will be liable for any claims or damages whatsoever associated with your use, inability to use, or your interaction with other users of the Software code or Software CLI, including any direct, indirect, incidental, special, exemplary, punitive or consequential damages, or loss of profits, cryptocurrencies, tokens, or anything else of value.