(var) - JavaScript

variable declarations (var/let/const), including destructuring patterns

(var name? init? kind?)

Where:

1. name: binding name or pattern *
2. init: initializer expression *
3. kind: the declaration keyword (var, let, or const) *

Matching:

1. var declarations, e.g. var x = 1
2. let declarations, e.g. let x = 1
3. const declarations, e.g. const x = 1
4. object destructuring, e.g. const { a } = obj
5. array destructuring, e.g. const [a] = list

Behavior

• When a declaration has multiple declarators, the statement matches if any declarator satisfies the constraints.

Examples

Find lingering var declarations before enforcing no-var.

(var _ _ (is var))

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

var legacy = 1
let modern = 2
const stable = 3

---

Locate environment destructuring for migration to a config loader.

(var (obj) (mem env process) (is const))

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

const { API_URL } = process.env
const { API_URL } = config
let { API_URL } = process.env

---

Identify array initializations to migrate to typed arrays.

(var _ (arr))

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

const items = []
let ids = [1, 2]
const count = 1

---

Arguments

name

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

init

1. Identifier: shorthand for (id)
   
2. Pattern: shorthand for (id)
   
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*)

kind

1. (is)
   
2. (:kind)
3. (:and)
4. (:not)
5. (:or)

Does NOT support: Refinement — Replacement