(comp) - JavaScript

computed property access and subscript expressions

(comp val?)

Where:

1. val: the expression inside the brackets *

Matching:

1. subscript expressions, e.g. obj[key]
2. computed property names in objects, e.g. { [key]: value }

Behavior

• Matches computed/dynamic property access using square brackets.
• Works in both member access (obj[expr]) and object literal property names ({ [expr]: value }).

Examples

Find dynamic property access using environment variables before refactoring.

(mem (comp (mem _ (id process))))

Selects in lines { 1, 2 } but not in { 3 }:

const apiUrl = config[process.env.NODE_ENV]
const setting = options[process.env.FEATURE_FLAG]
const value = data[userInput]

---

Locate computed property names in objects for ES5 compatibility check.

(obj (prop (comp)))

Selects in lines { 1, 3 } but not in { 2 }:

const obj1 = { [key]: value }
const obj2 = { name: value }
const obj3 = { [Symbol.iterator]: function*() {} }

---

Find array access with string literals to convert to dot notation.

(mem (comp (str)))

Selects in lines { 1, 2 } but not in { 3 }:

const name = user['name']
const age = user['age']
const value = data[dynamicKey]

---

Arguments

val

1. Identifier: shorthand for (id)
   
2. String: shorthand for (str)
   
3. (:ref)
4. (:into)
5. (:nearest)
6. (:and)
7. (:or)
8. (:not)
9. (:text)
10. (:kind)
11. (:replace)
12. (:replace-in)
13. (:capture)
14. (arr)
15. (bin)
16. (bool)
17. (call)
18. (comp)
19. (fun)
20. (id)
21. (id+)
22. (jsx)
23. (mem)
24. (null)
25. (num)
26. (obj)
27. (of)
28. (regex)
29. (regex+)
30. (str)
31. (str*)
32. (str+)
33. (tpl)
34. (tpl*)