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fix(linter/array-type): false negative with arrays in generic args #12500

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Merged
merged 1 commit into from
Jul 24, 2025
Merged

fix(linter/array-type): false negative with arrays in generic args #12500

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77 changes: 77 additions & 0 deletions crates/oxc_linter/src/rules/typescript/array_type.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -215,6 +215,11 @@ impl Rule for ArrayType {
ctx,
);
}
AstKind::TSTypeParameterInstantiation(ts_type_param_instantiation) => {
for param in &ts_type_param_instantiation.params {
check(param, default_config, readonly_config, ctx);
}
}
_ => {}
}
}
Expand Down Expand Up @@ -1256,6 +1261,36 @@ fn test() {
("type x = Array<number>[]", None),
("const arr: Array<Array<number>>[] = [];", None),
("export function fn4(arr: Array<number>[]) { return arr; }", None),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<{name: string}[]>([]);",
Some(serde_json::json!([{"default":"array-simple"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<Array<{name: string}>>([]);",
Some(serde_json::json!([{"default":"array"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<string[]>([]);",
Some(serde_json::json!([{"default":"generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<(string | number)[]>([]);",
Some(serde_json::json!([{"default":"generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<readonly string[]>([]);",
Some(serde_json::json!([{"default":"generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<ReadonlyArray<string>>([]);",
Some(serde_json::json!([{"default":"array"}])),
),
];

let fix: Vec<(&str, &str, Option<serde_json::Value>)> = vec![
Expand Down Expand Up @@ -1788,6 +1823,48 @@ fn test() {
"let a: Promise<Array<string>> = Promise.resolve([]);",
Some(serde_json::json!([{"default": "generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<{name: string}[]>([]);",
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<Array<{name: string}>>([]);",
Some(serde_json::json!([{"default":"array-simple"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<Array<{name: string}>>([]);",
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<{name: string}[]>([]);",
Some(serde_json::json!([{"default":"array"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<string[]>([]);",
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<Array<string>>([]);",
Some(serde_json::json!([{"default":"generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<(string | number)[]>([]);",
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<Array<string | number>>([]);",
Some(serde_json::json!([{"default":"generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<readonly string[]>([]);",
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<ReadonlyArray<string>>([]);",
Some(serde_json::json!([{"default":"generic"}])),
),
(
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<ReadonlyArray<string>>([]);",
"function testFn<T>(param: T) { return param; }
export const test2 = testFn<readonly string[]>([]);",
Some(serde_json::json!([{"default":"array"}])),
),
];

Tester::new(ArrayType::NAME, ArrayType::PLUGIN, pass, fail)
Expand Down
62 changes: 62 additions & 0 deletions crates/oxc_linter/src/snapshots/typescript_array_type.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -652,6 +652,13 @@ source: crates/oxc_linter/src/tester.rs
╰────
help: Replace `string[]` with `Array<string>`.

⚠ typescript-eslint(array-type): Array type using 'string[]' is forbidden. Use 'Array<string>' instead.
╭─[array_type.ts:1:16]
1 │ let a: Promise<string[]> = Promise.resolve([]);
· ────────
╰────
help: Replace `string[]` with `Array<string>`.

⚠ typescript-eslint(array-type): Array type using 'Array<number>' is forbidden. Use 'number[]' instead.
╭─[array_type.ts:1:10]
1 │ type x = Array<number>[]
Expand All @@ -666,9 +673,64 @@ source: crates/oxc_linter/src/tester.rs
╰────
help: Replace `Array<Array<number>>` with `Array<number>[]`.

⚠ typescript-eslint(array-type): Array type using 'Array<number>' is forbidden. Use 'number[]' instead.
╭─[array_type.ts:1:18]
1 │ const arr: Array<Array<number>>[] = [];
· ─────────────
╰────
help: Replace `Array<number>` with `number[]`.

⚠ typescript-eslint(array-type): Array type using 'Array<number>' is forbidden. Use 'number[]' instead.
╭─[array_type.ts:1:26]
1 │ export function fn4(arr: Array<number>[]) { return arr; }
· ─────────────
╰────
help: Replace `Array<number>` with `number[]`.

⚠ typescript-eslint(array-type): Array type using 'T[]' is forbidden for non-simple types. Use 'Array<T>' instead.
╭─[array_type.ts:2:29]
1 │ function testFn<T>(param: T) { return param; }
2 │ export const test2 = testFn<{name: string}[]>([]);
· ────────────────
╰────
help: Replace `{name: string}[]` with `Array<{name: string}>`.

⚠ typescript-eslint(array-type): Array type using 'Array<T>' is forbidden. Use 'T[]' instead.
╭─[array_type.ts:2:29]
1 │ function testFn<T>(param: T) { return param; }
2 │ export const test2 = testFn<Array<{name: string}>>([]);
· ─────────────────────
╰────
help: Replace `Array<{name: string}>` with `{name: string}[]`.

⚠ typescript-eslint(array-type): Array type using 'string[]' is forbidden. Use 'Array<string>' instead.
╭─[array_type.ts:2:29]
1 │ function testFn<T>(param: T) { return param; }
2 │ export const test2 = testFn<string[]>([]);
· ────────
╰────
help: Replace `string[]` with `Array<string>`.

⚠ typescript-eslint(array-type): Array type using 'T[]' is forbidden. Use 'Array<T>' instead.
╭─[array_type.ts:2:29]
1 │ function testFn<T>(param: T) { return param; }
2 │ export const test2 = testFn<(string | number)[]>([]);
· ───────────────────
╰────
help: Replace `(string | number)[]` with `Array<string | number>`.

⚠ typescript-eslint(array-type): Array type using 'readonly string[]' is forbidden. Use 'ReadonlyArray<string>' instead.
╭─[array_type.ts:2:29]
1 │ function testFn<T>(param: T) { return param; }
2 │ export const test2 = testFn<readonly string[]>([]);
· ─────────────────
╰────
help: Replace `readonly string[]` with `ReadonlyArray<string>`.

⚠ typescript-eslint(array-type): Array type using 'ReadonlyArray<string>' is forbidden. Use 'readonly string[]' instead.
╭─[array_type.ts:2:29]
1 │ function testFn<T>(param: T) { return param; }
2 │ export const test2 = testFn<ReadonlyArray<string>>([]);
· ─────────────────────
╰────
help: Replace `ReadonlyArray<string>` with `readonly string[]`.
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