Solparse

Common errors

• Syntax error: Expected "!= ", "%", "%=", "&", "&&", "&=", "*", "*=", "+", "++", "+", ",", "-", "--", "-=", "/", "/*", "/=", ";", "<", "<<", "<<=", "<=", "=", "==", ">", ">=", ">>", ">>=", ">>>", "?", "^", "^=", "|", "|=", "||", comment, end of line, or whitespace but "(" found.

  cause This generic syntax error often indicates that the Solidity code being parsed contains syntax elements not recognized by the older `solparse` version. A common example is the `emit` keyword for events, introduced in Solidity 0.4.21.
  fix Ensure your Solidity code adheres to an older syntax version supported by `solparse` (e.g., pre-0.4.21 for certain features), or migrate to a more current Solidity parser that supports modern syntax.

• TypeError: Cannot read properties of undefined (reading 'name')

  cause Attempting to access properties of the AST object, such as `ast.body[0].name`, when the parsing failed or the AST structure is unexpected for the given Solidity code. This often happens if the input is invalid or a parsing error occurred before the AST could be fully formed.
  fix Wrap `parse()` calls in a try-catch block to handle `SyntaxError` or `ParserError` gracefully. Inspect the `ast` object structure after successful parsing to ensure it matches expectations before accessing properties. Consider `console.log(JSON.stringify(ast, null, 2))` for debugging.

Warnings

• breaking Solparse does not guarantee backward compatibility and may introduce breaking changes without major version increments. Its development is tied to `Ethlint`'s needs rather than general public API stability.
  Fix: Pin `solparse` to a fixed version in your `package.json` (e.g., `"solparse": "2.2.8"`) and manually test before updating.
• gotcha The package has not been updated in over seven years (last published January 13, 2019) and may not support newer Solidity syntax features (e.g., `emit` syntax introduced in 0.4.21, or features in Solidity 0.5.x, 0.6.x, 0.7.x, 0.8.x and later).
  Fix: For projects requiring support for modern Solidity, consider alternative parsers such as `solparse-exp-jb` or `@solidity-parser/parser` which are actively maintained and support newer language versions.
• gotcha The `solparse` package primarily targets CommonJS environments. While Node.js can often import CJS modules, direct named ESM imports will not work as the package exports a single default function.
  Fix: Use `import parse from 'solparse';` for ESM or `const parse = require('solparse');` for CommonJS to correctly access the parsing function.

Install

• npm install solparse npm
• yarn add solparse yarn
• pnpm add solparse pnpm

Imports

• parse
  wrong:

  import { parse } from 'solparse';
  const solparse = require('solparse');

  correct:

  import parse from 'solparse';

  The 'solparse' package exports the 'parse' function as its default export. For older Node.js or CommonJS environments, use `const parse = require('solparse');`. Named imports like `{ parse }` will not work.
• ParserError
  wrong:

  import { ParserError } from 'solparse';

  correct:

  import parse from 'solparse';
  // ParserError is typically accessed via the default export if available
  // or caught in a try-catch block and checked with `e instanceof parse.ParserError`

  ParserError is part of the error handling mechanism and is usually an instance of a class or a property on the default export. It is not directly exported as a named symbol.

Quickstart

Demonstrates how to parse a basic Solidity contract string using solparse and log the resulting Abstract Syntax Tree (AST), including basic error handling.

import parse from 'solparse';

const solidityCode = `
pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 public storedData;

    function set(uint256 x) public {
        storedData = x;
    }

    function get() public view returns (uint256) {
        return storedData;
    }
}
`;

try {
    const ast = parse(solidityCode);
    console.log('Successfully parsed Solidity code. AST:', JSON.stringify(ast, null, 2));
    // You can now traverse and analyze the AST
    console.log('Contract name:', ast.body[0].name);
} catch (e) {
    if (e instanceof Error && e.name === 'SyntaxError') {
        console.error('Parsing error:', e.message);
    } else {
        console.error('An unexpected error occurred:', e);
    }
}