import { getNodeText, getChildByField } from '../tree-sitter-helpers';

import type { LanguageExtractor } from '../tree-sitter-types';

export const javascriptExtractor: LanguageExtractor = {

functionTypes: ['function_declaration', 'arrow_function', 'function_expression'],

classTypes: ['class_declaration'],

methodTypes: ['method_definition', 'field_definition'],

interfaceTypes: [],

structTypes: [],

enumTypes: [],

typeAliasTypes: [],

importTypes: ['import_statement'],

callTypes: ['call_expression'],

variableTypes: ['lexical_declaration', 'variable_declaration'],

nameField: 'name',

bodyField: 'body',

resolveBody: (node, bodyField) => {

// field_definition (arrow function class fields) nest the body inside

// an arrow_function or function_expression child:

// field_definition → arrow_function → body (statement_block)

// Also handles wrapper patterns like: field = throttle((e) => { ... })

// field_definition → call_expression → arguments → arrow_function → body

if (node.type === 'field_definition') {

for (let i = 0; i < node.namedChildCount; i++) {

const child = node.namedChild(i);

if (!child) continue;

if (child.type === 'arrow_function' || child.type === 'function_expression') {

return getChildByField(child, bodyField);

}

if (child.type === 'call_expression') {

const args = getChildByField(child, 'arguments');

if (args) {

for (let j = 0; j < args.namedChildCount; j++) {

const arg = args.namedChild(j);

if (arg && (arg.type === 'arrow_function' || arg.type === 'function_expression')) {

return getChildByField(arg, bodyField);

}

}

}

}

}

}

return null;

},

paramsField: 'parameters',

getSignature: (node, source) => {

const params = getChildByField(node, 'parameters');

return params ? getNodeText(params, source) : undefined;

},

isExported: (node, _source) => {

let current = node.parent;

while (current) {

if (current.type === 'export_statement') return true;

current = current.parent;

}

return false;

},

isAsync: (node) => {

for (let i = 0; i < node.childCount; i++) {

const child = node.child(i);

if (child?.type === 'async') return true;

}

return false;

},

isConst: (node) => {

if (node.type === 'lexical_declaration') {

for (let i = 0; i < node.childCount; i++) {

const child = node.child(i);

if (child?.type === 'const') return true;

}

}

return false;

},

extractImport: (node, source) => {

const sourceField = node.childForFieldName('source');

if (sourceField) {

const moduleName = source.substring(sourceField.startIndex, sourceField.endIndex).replace(/['"]/g, '');

if (moduleName) {

return { moduleName, signature: source.substring(node.startIndex, node.endIndex).trim() };

}

}

return null;

},

};