https://github.com/js-cst-tokens/cst-tokens comment attachment example

1.fixture.js

function /*1*/ foo /*2*/ (/*3*/) /*4*/ {/*5*/} /*6*/

2.cst.json

{
  "type": "CSTFragment",
  "cstTokens": [
    { "type": "Reference",       "value": "fragment" },
    { "type": "Literal",         "value": " "        },
    { "type": "CommentStart",    "value": "/*"       },
    { "type": "Literal",         "value": "6"        },
    { "type": "CommentEnd",      "value": "*/"       }
  ],
  "fragment": {
    "type": "Program",
    "cstTokens": [
      { "type": "Reference", "value": "body" }
    ],
    "sourceType": "module",
    "body": [
      {
        "type": "FunctionDeclaration",
        "cstTokens": [
          { "type": "Keyword",         "value": "function" },
          { "type": "Literal",         "value": " "        },
          { "type": "CommentStart",    "value": "/*"       },
          { "type": "Literal",         "value": "1"        },
          { "type": "CommentEnd",      "value": "*/"       },
          { "type": "Literal",         "value": " "        },
          { "type": "Reference",       "value": "id"       },
          { "type": "Literal",         "value": " "        },
          { "type": "CommentStart",    "value": "/*"       },
          { "type": "Literal",         "value": "2"        },
          { "type": "CommentEnd",      "value": "*/"       },
          { "type": "Literal",         "value": " "        },
          { "type": "LeftPunctuator",  "value": "("        },
          { "type": "CommentStart",    "value": "/*"       },
          { "type": "Literal",         "value": "3"        },
          { "type": "CommentEnd",      "value": "*/"       },
          { "type": "RightPunctuator", "value": ")"        },
          { "type": "CommentStart",    "value": "/*"       },
          { "type": "Literal",         "value": "4"        },
          { "type": "CommentEnd",      "value": "*/"       },
          { "type": "Literal",         "value": " "        },
          { "type": "Reference",       "value": "body"     }
        ],
        "id": {
          "type": "Identifier",
          "cstTokens": [
            { "type": "SymbolDefinition", "value": "foo" }
          ],
          "name": "foo"
        },
        "params": [],
        "body": {
          "type": "BlockStatement",
          "cstTokens": [
            { "type": "LeftPunctuator",  "value": "{"  },
            { "type": "CommentStart",    "value": "/*" },
            { "type": "Literal",         "value": "5"  },
            { "type": "CommentEnd",      "value": "*/" },
            { "type": "RightPunctuator", "value": "}"  }
          ],
          "body": []
        },
        "async": false,
        "generator": false
      }
    ]
  }
}

3.reprinted.js

function /*1*/ foo /*2*/ (/*3*/) /*4*/ {/*5*/} /*6*/