!macOS
!Linux
!TypeScript

cypher-parser

A cypher graph query language parser/linter addon module for NodeJS.
It relies on libcypher-parser and rapidjson under the hood.

Features

* Promise support
* C++ addon parses queries in a worker thread
* Typescript support with interfaces defined for full AST
* Outputs json AST
* Outputs text description of AST
* Outputs error with position and description
* Optional ANSI color support for text and error output
* API Documentation

Supported Systems

- Node 8, 9, 10, 11, 12, 14
- linux-x64
- darwin-x64 (OSX >= 10.7)

Sorry Windows users, the libcypher-parser depencency cannot be built on your systems. A port is currently in progress. Meanwhile, you can still run a docker container on Windows to use it.

Installation

``sh
npm install cypher-parser
`
The installation process will try to download a pre-built binary module matching your Node and OS version.
If it cannot be found, you will have to first run the steps in Custom Build.

Usage

The cypher-parser module has only one exported function: parse.
It takes a query string or a ParseParameters object as input, and returns a promise as output.
On success, the promise returns a ParseResult object or a string.
On failure, a CypherParserError object is thrown. It contains a ParseResult object for more details.

`typescript
export interface ParseParameters {
query: string; // The cypher query to parse.
width?: number; // Width of the text AST output. Default 0.
dumpAst?: boolean; // If true, the ParseResult will contain a text description of the AST tree. Default false.
rawJson?: boolean; // If true, the result will be a json string instead of a ParseResult object. Default false.
colorize?: boolean; // If true, the text AST output and error descriptions will be ANSI colored. Nice for console output.
parseOnlyStatements?: boolean; // If true, client commands will not be parsed. Default true.
}
`

`typescript
export interface ParseResult {
ast: string; // A text description of the AST tree.
errors: ParseError[]; // Array of parse error encountered.
directives: parseResultDirective[]; // Parsed cypher directives.
roots: ast.AstNode[]; // The AST tree of the parsed query. Can be walked by programs. See API doc for details.
nnodes: number; // Number of nodes parsed.
}
`

* Typescript
`typescript
import * as cypher from "cypher-parser";

async function testCypher() {
const query = "MATCH (node1:Label1)-->(node2:Label2)\n" +
"WHERE node1.propertyA = {value}\n" +
"RETURN node2.propertyA, node2.propertyB";

try {
const result = await cypher.parse({
query: query,
dumpAst: true,
colorize: true
});
console.log(result.ast);
} catch (e) {
const result: cypher.CypherParserError = e;
for (const error of result.parseResult.errors) {
console.log(error.position.line + ":" + error.position.column + ": " + error.message);
console.log(error.context);
console.log(" ".repeat(error.contextOffset) + "^");
console.log(result.parseResult.ast);
}
}
}
`

* Javascript
`Javascript
var cypher = require('cypher-parser');

async function testCypher() {
var query = "MATCH (node1:Label1)-->(node2:Label2)\n" +
"WHERE node1.propertyA = {value}\n" +
"RETURN node2.propertyA, node2.propertyB";

try {
var result = await cypher.parse({
query: query,
dumpAst: true,
colorize: true
});
console.log(result.ast);
} catch (e) {
for (var i = 0; i < e.parseResult.errors.length; i++) {
var error = e.errors[i];
console.log(error.position.line + ":" + error.position.column + ": " + error.message);
console.log(error.context);
console.log(" ".repeat(error.contextOffset) + "^");
console.log(e.parseResult.ast);
}
}
}
`

Custom Build

In case a binary distribution is not available for your system, you must install build tools and compile the libcypher-parser dependency like this:

* make, C++ and Pyton
`sh
sudo apk add make gcc g++ python
`

* libcypher-parser
`sh
wget https://github.com/cleishm/libcypher-parser/releases/download/v0.6.2/libcypher-parser-0.6.2.tar.gz \
&& tar zxvpf libcypher-parser-0.6.2.tar.gz \
&& rm libcypher-parser-0.6.2.tar.gz \
&& cd libcypher-parser-0.6.2 \
&& ./configure --prefix=/usr/local CFLAGS='-fPIC' \
&& make clean check \
&& make install \
&& cd .. \
&& rm -rf libcypher-parser-0.6.2
``