input.ts

function* iterable() {
    yield 1;
    yield 2;
  }
  async function* asyncIterable() {
    yield 1;
    yield 2;
  }
  const subinput = [
    { a: "a value 1", b: "b value" },
    { c: "c value", a: "a value 2" },
  ];
  const nullObj = Object.create(null);
  nullObj.a = "a value";
  const input = [
    subinput,
    "d",
    "e",
    null,
    nullObj,
    new Test("f"),
    new Date(),
    Promise.resolve({ p: "1" }),
    Promise.resolve(iterable()),
    Promise.resolve(asyncIterable()),
    Promise.resolve(BigInt("42")),
    Promise.resolve(Symbol.for("42")),
  ];

output-formatted.ts

// find: ^<(\$[PE]?\d+)>
// replace: const $1 = <$1>

const $1 = <$1>[
  <$2>[
    <$3>{ a: "a value 1", b: "b value" },
    <$4>{ c: "c value", a: "a value 2" },
  ],
  "d",
  "e",
  null,
  <$5$null>(<$5>{ a: "a value" }),
  <$6>{ a: "f" },
  <$7$Date$>(<$7>{ iso: "2024-11-07T08:07:46.903Z" }),
  $P8,
  $P9,
  $P10,
  $P11,
  $P12,
];
const $P8 = <$P8>(<$13>{ p: "1" });
const $P9 = <$P9>(<$14>[1, 2]);
const $P10 = <$P10>(<$15$AsyncIterable$>(<$15>{ next: $P16 }));
const $P11 = <$P11>(<$17$BigInt$>(<$17>{ value: "42" }));
const $P12 = <$P12>(<$18$Symbol$>(<$18>{ key: "42" }));
const $P16 = <$P16>(<$19>{ value: 1, next: $P20 });
const $P20 = <$P20>(<$21>{ value: 2, next: $P22 });
const $P22 = <$P22>(<$23>{});

output.ts

<$1>[<$2>[<$3>{"a":"a value 1","b":"b value"},<$4>{"c":"c value","a":"a value 2"}],"d","e",null,<$5$null><$5>{"a":"a value"},<$6>{"a":"f"},<$7$Date$><$7>{"iso":"2024-11-07T08:07:46.903Z"},$P8,$P9,$P10,$P11,$P12]
<$P8><$13>{"p":"1"}
<$P9><$14>[1,2]
<$P10><$15$AsyncIterable$><$15>{"next":$P16}
<$P11><$17$BigInt$><$17>{"value":"42"}
<$P12><$18$Symbol$><$18>{"key":"42"}
<$P16><$19>{"value":1,"next":$P20}
<$P20><$21>{"value":2,"next":$P22}
<$P22><$23>{}