no_unused/imports.bend

bend-lint-rules@0.2.1.0 · 52 lines · 0 definitions

1# no_unused/imports: an import that nothing in its file uses.
2# Fix: deletes the import's line.
3# Heuristics: a use is a name written through the import's alias, or, for Base, a name that only Base
4# declares (Imported in lint.bend).
5import Base
6import bend-lint-api@0.2.1.0/linter/lint.bend as Lint
7import bend-lint-api@0.2.1.0/shared/lists.bend as Lists
8import bend-lint-api@0.2.1.0/shared/strings.bend as Strings
9
10# The fix that deletes the import's line.
11def deleted(+text: String, path: String, at: U32) -> List<&2, Lint.Fix>:
12  +beg = Strings.line_start(text, at)
13  [
14    Lint.Fix{
15      "Remove the import",
16      [Lint.Replace{Lint.Span{path, beg, Strings.line_end(text, beg)}, ""}]
17    }
18  ]
19
20def unused(text: String, d: Lint.Declaration) -> List<&2, Lint.Finding>:
21  match d:
22    case Lint.Declaration{
23      Lint.Node{Lint.Import{t}, name, Some{Lint.Span{+path, +beg, end}}, k, f},
24      Nil{}
25    }:
26      [
27        Lint.Finding{
28          Lint.Warning{},
29          Lint.Span{path, beg, end},
30          "Remove the import " ++ name ++ ": nothing uses it.",
31          deleted(text, path, beg)
32        }
33      ]
34    case _:
35      []
36
37def findings(
38  declarations: List<&2, Lint.Declaration>,
39  +text: String,
40  out: List<&2, Lint.Finding>
41) -> List<&2, Lint.Finding>:
42  match declarations:
43    case Nil{}:
44      List.reverse(&2, Lint.Finding, out)
45    case Con{d, rest}:
46      findings(rest, text, Lists.onto(&2, Lint.Finding, unused(text, d), out))
47
48def run(+here: Lint.Here) -> Lint.Ask(List<&2, Lint.Finding>):
49  Lint.done(findings(Lint.Here.declarations(here), Lint.Here.text(here), []))
50
51def rule() -> Lint.Rule:
52  Lint.Rule{Lint.Needs{False{}, True{}}, [], Lint.OnFile{run}}