nandi.uk
Fork of daniellemaywood.uk/gleam — Wasm codegen work
add and update tests for guard variable pollution fix
author
Elias
committer
Louis Pilfold
date
(Nov 6, 2025, 3:02 PM UTC)
commit
53ed4c7e
53ed4c7ecd6afbb24e2dee22a6d42eddf0d9ed7a
parent
ec332818
ec3328181e73191043691a4645371cfe8a284879
+100
-4
+5
CHANGELOG.md
+5
CHANGELOG.md
···
158
158
- Fixed a bug where useless comparison warnings for floats compared literal
159
159
strings, claiming for example that `1.0 == 1.` was always false.
160
160
([fruno](https://github.com/fruno-bulax/))
161
+
162
+
- Fixed a bug where pattern variables in case clause guards would incorrectly
163
+
shadow outer scope variables in other branches when compiling to JavaScript.
164
+
([Elias Haider](https://github.com/EliasDerHai))
165
+
+27
compiler-core/src/javascript/tests/case_clause_guards.rs
+27
compiler-core/src/javascript/tests/case_clause_guards.rs
···
576
576
"#,
577
577
);
578
578
}
579
+
580
+
// https://github.com/gleam-lang/gleam/issues/5094
581
+
#[test]
582
+
fn guard_pattern_does_not_shadow_outer_scope() {
583
+
assert_js!(
584
+
r#"
585
+
pub type Option(a) {
586
+
Some(a)
587
+
None
588
+
}
589
+
590
+
pub type Container {
591
+
Container(x: Option(Int))
592
+
}
593
+
594
+
pub fn main() {
595
+
let x: Option(Int) = Some(42)
596
+
case Some(1) {
597
+
Some(x) if x < 0 -> Container(None)
598
+
_ -> {
599
+
Container(x:)
600
+
}
601
+
}
602
+
}
603
+
"#,
604
+
);
605
+
}
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__guard_variable_only_brought_into_scope_when_needed_1.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__guard_variable_only_brought_into_scope_when_needed_1.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__list_with_guard.snap
+2
-2
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case__list_with_guard.snap
+64
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__guard_pattern_does_not_shadow_outer_scope.snap
+64
compiler-core/src/javascript/tests/snapshots/gleam_core__javascript__tests__case_clause_guards__guard_pattern_does_not_shadow_outer_scope.snap
···
1
+
---
2
+
source: compiler-core/src/javascript/tests/case_clause_guards.rs
3
+
expression: "\npub type Option(a) {\n Some(a)\n None\n}\n\npub type Container {\n Container(x: Option(Int))\n}\n\npub fn main() {\n let x: Option(Int) = Some(42)\n case Some(1) {\n Some(x) if x < 0 -> Container(None)\n _ -> {\n Container(x:)\n }\n }\n}\n"
4
+
---
5
+
----- SOURCE CODE
6
+
7
+
pub type Option(a) {
8
+
Some(a)
9
+
None
10
+
}
11
+
12
+
pub type Container {
13
+
Container(x: Option(Int))
14
+
}
15
+
16
+
pub fn main() {
17
+
let x: Option(Int) = Some(42)
18
+
case Some(1) {
19
+
Some(x) if x < 0 -> Container(None)
20
+
_ -> {
21
+
Container(x:)
22
+
}
23
+
}
24
+
}
25
+
26
+
27
+
----- COMPILED JAVASCRIPT
28
+
import { CustomType as $CustomType } from "../gleam.mjs";
29
+
30
+
export class Some extends $CustomType {
31
+
constructor($0) {
32
+
super();
33
+
this[0] = $0;
34
+
}
35
+
}
36
+
export const Option$Some = ($0) => new Some($0);
37
+
export const Option$isSome = (value) => value instanceof Some;
38
+
export const Option$Some$0 = (value) => value[0];
39
+
40
+
export class None extends $CustomType {}
41
+
export const Option$None = () => new None();
42
+
export const Option$isNone = (value) => value instanceof None;
43
+
44
+
export class Container extends $CustomType {
45
+
constructor(x) {
46
+
super();
47
+
this.x = x;
48
+
}
49
+
}
50
+
export const Container$Container = (x) => new Container(x);
51
+
export const Container$isContainer = (value) => value instanceof Container;
52
+
export const Container$Container$x = (value) => value.x;
53
+
export const Container$Container$0 = (value) => value.x;
54
+
55
+
export function main() {
56
+
let x = new Some(42);
57
+
let $ = new Some(1);
58
+
let x$1 = $[0];
59
+
if (x$1 < 0) {
60
+
return new Container(new None());
61
+
} else {
62
+
return new Container(x);
63
+
}
64
+
}