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.

Table Of Contents

• Packages
• Features
• Output
• Using PgProtoParser
• Using the CLI
• Options
• Meta AST
• Related
• Disclaimer

Packages

• pg-proto-parser
• @launchql/proto-cli

Features

• Parses protobuf definitions and creates a structured representation in TypeScript.
• Generates TypeScript interfaces for protobuf messages.
• Creates utility functions for enum value conversions.
• Produces JSON files mapping enum names to integer values and vice versa

Output

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.

Using PgProtoParser

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();

Using the CLI

npm install -g @launchql/proto-cli

First, download the latest protobuf definition from libpg_query:

wget https://raw.githubusercontent.com/pganalyze/libpg_query/16-latest/protobuf/pg_query.proto

Run the CLI to parse the protobuf file and generate TypeScript outputs:

pg-proto-parser --input pg_query.proto --output out

Options

This table describes the options available for PgProtoParserOptions, their functionality, and default values.

Option	Description	Default Value
outDir	The directory where the generated files will be saved.	process.cwd() + "/out"
exclude	List of type or enum names to exclude during processing.	[]
utils.enums.enabled	Whether to generate TypeScript utility functions for enums.	false
utils.enums.filename	Filename for the generated enums utilities.	'utils.ts'
utils.astHelpers.enabled	Outputs TypeScript helpers for building PostgreSQL ASTs.	false
utils.astHelpers.wrappedTypesSource	Path to the TypeScript types to use when generating AST helpers.	'./wrapped'
utils.astHelpers.inlineNestedObj	Whether to inline nested-obj code within the generated file.	false
utils.astHelpers.nestedObjFile	Filename for the inlined nested-obj code, if inlineNestedObj is true.	'nested-obj.ts'
utils.astHelpers.filename	Filename for the generated AST helpers.	'asts.ts'
types.enabled	Whether to generate TypeScript interfaces for protobuf messages.	false
types.filename	Filename for the generated TypeScript interfaces.	'types.ts'
types.optionalFields	Generates TypeScript interfaces with optional fields mapping to the PostgreSQL node types' fields; sets all fields to optional.	true
types.enumsSource	Path to the TypeScript enums to use when generating TypeScript interfaces.	'./enums'
types.wrapped.enabled	Whether to generate wrapped TypeScript interfaces to match AST nodes.	false
types.wrapped.enumsSource	Path to the TypeScript enums to use when generating wrapped TypeScript interfaces.	'./enums'
types.wrapped.filename	Filename for the generated wrapped TypeScript interfaces.	'wrapped.ts'
enums.enabled	Outputs TypeScript enum types for the PostgreSQL enums.	false
enums.filename	Filename for the generated TypeScript enums.	'enums.ts'
enums.enumsAsTypeUnion	Uses strings to define enum types as specified for the fields of each proto message type.	true
enums.json.enabled	Whether to generate JSON files mapping enum names to integer values and vice versa.	false
enums.json.toIntOutFile	Output file name for the JSON mapping of enum names to integer values.	'enums2int.json'
enums.json.toStrOutFile	Output file name for the JSON mapping of integer values to enum names.	'enums2str.json'
enums.removeUndefinedAt0	Removes the initial UNDEFINED enum entry and adjusts the subsequent values by decrementing them.	true
includeHeader	Includes a header at the top of generated TypeScript files to avoid manual manipulation which could cause issues in CI/CD pipelines.	true

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, assuming you import the ast as as default import from @pgsql/utils:

import { 
  generateTsAstCodeFromPgAst
} from 'pg-proto-parser';
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
const tsAstBuilderCode = generateTsAstCodeFromPgAst(
  pgAst[0].RawStmt.stmt
);

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

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

Related

• launchql/pgsql-parser: A node.js PostgreSQL parser/deparser that interprets and converts PostgresSQL syntax.
• launchql/libpg-query-node: Node.js bindings for the libpg_query library, allowing parsing of PostgreSQL queries into parse trees.
• @pgsql/enums: Provides PostgreSQL AST enums in TypeScript, enhancing type safety and usability in projects interacting with PostgreSQL AST nodes.
• @pgsql/types: Offers TypeScript type definitions for PostgreSQL AST nodes, facilitating type-safe construction, analysis, and manipulation of ASTs.
• @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.

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.