Get all JS functions from string using single regex

parseJsFunctionsFromString.js

/*
Return array, which contains match arrays
Groups:
  [0] - whole function 
  [1] - function name
  [2] - function parameters string
  [3] - function body (excluding brackets)
Or use named groups (?<groupName>...) if ES2018
*/
const definedJsFunctionsRegex = /function\s*([A-z0-9]+)?\s*\(([^)(]+|\((?:[^)(]+|\([^)(]*\))*\))*\)\s*\{((?:[^}{]+|\{[^}{]*\}|[^}]|\}(\"|\'|\`))*)*\}/g;
const testStr = `
function a (a,b) { hfgdhfhjg
  fdgdhfytr
  confsf 
  dfdasg  	
  }
  
  
  function test() {
  fdsf
  consol.gkgd("fsdfs");
  const a = function(m) {fuck you};
  a();
  return 1
  }
  
  function(fds) { obj = {} return "}" }
  

  function r () { obj = {}; a = []; }
  
  function test(float, best) { 
  console.log("Well");
  }
  
  function a(){console.log('a')} function b(){console.log('b')}
`;

let matches = [...testStr.matchAll(definedJsFunctionsRegex)];
console.log(matches);
/*
Example output: 

(7) […]
​
0: Array(5) [ "function a (a,b) { hfgdhfhjg\n  fdgdhfytr\n  confsf \n  dfdasg  \t\n  }", "a", "a,b", … ]
​
1: Array(5) [ "function test() {\n  fdsf\n  consol.gkgd(\"fsdfs\");\n  const a = function(m) {fuck you};\n  a();\n  return 1\n  }", "test", undefined, … ]
​
2: Array(5) [ "function(fds) { obj = {} return \"}\" }", undefined, "fds", … ]
​
3: Array(5) [ "function r () { obj = {}; a = []; }", "r", undefined, … ]
​
4: Array(5) [ "function test(float, best) { \n  console.log(\"Well\");\n  }", "test", "float, best", … ]
​
5: Array(5) [ "function a(){console.log('a')}", "a", undefined, … ]
​
6: Array(5) [ "function b(){console.log('b')}", "b", undefined, … ]
​
length: 7
​
<prototype>: Array []
debugger eval code:31:9


*/