feat(linter/typescript): implement no-unsafe-enum-assignment rule (#28117)

Register `typescript/no-unsafe-enum-assignment` as a type-aware rule backed by oxlint-tsgolint 7.0.2005, following https://github.com/oxc-project/tsgolint/pull/1316. Add rule documentation and regenerate the rule registry, JSON schema, and TypeScript config types.

Extend the existing type-aware CLI fixture with unsafe assignments, arguments, returns, assertions, mutations, and enum-key access, plus valid enum-member and bitwise-combination cases. Reuse the existing tests and update their diagnostic and count snapshots.

apps/oxlint/fixtures/cli/tsgolint/.oxlintrc.json

@@ -32,6 +32,7 @@
     "typescript/no-unsafe-argument": "error",
     "typescript/no-unsafe-assignment": "error",
     "typescript/no-unsafe-call": "error",
+    "typescript/no-unsafe-enum-assignment": "error",
     "typescript/no-unsafe-enum-comparison": "error",
     "typescript/no-unsafe-member-access": "error",
     "typescript/no-unsafe-return": "error",

apps/oxlint/fixtures/cli/tsgolint/no-unsafe-enum-assignment.ts

@@ -0,0 +1,24 @@
+enum Fruit {
+  Apple,
+  Banana,
+}
+
+const fruit: Fruit = 1;
+function takesFruit(value: Fruit): void {}
+takesFruit(1);
+function getFruit(): Fruit {
+  return 0;
+}
+const asserted = 1 as Fruit;
+let mutable = Fruit.Apple;
+mutable++;
+declare const names: { [key in Fruit]: string };
+names[0];
+
+// Enum members and bitwise combinations are allowed.
+const safeFruit: Fruit = Fruit.Apple;
+takesFruit(Fruit.Banana);
+const combined: Fruit = Fruit.Apple | Fruit.Banana;
+names[Fruit.Apple];
+
+export {};

apps/oxlint/src-js/package/config.generated.ts

@@ -1490,6 +1490,7 @@ export interface DummyRuleMap {
   "typescript/no-unsafe-assignment"?: RuleNoConfig;
   "typescript/no-unsafe-call"?: RuleNoConfig;
   "typescript/no-unsafe-declaration-merging"?: RuleNoConfig;
+  "typescript/no-unsafe-enum-assignment"?: RuleNoConfig;
   "typescript/no-unsafe-enum-comparison"?: RuleNoConfig;
   "typescript/no-unsafe-function-type"?: RuleNoConfig;
   "typescript/no-unsafe-member-access"?: RuleNoConfig | [AllowWarnDeny, NoUnsafeMemberAccessConfig];

apps/oxlint/src/snapshots/fixtures__cli__tsgolint_--type-aware --silent@oxlint.snap

@@ -6,8 +6,8 @@ arguments: --type-aware --silent
 working directory: fixtures/cli/tsgolint
 ----------
 
-Found 0 warnings and 86 errors.
-Finished in <variable>ms on 61 files with 60 rules using 1 threads.
+Found 0 warnings and 92 errors.
+Finished in <variable>ms on 62 files with 61 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

apps/oxlint/src/snapshots/fixtures__cli__tsgolint_--type-aware -c config-test.json@oxlint.snap

@@ -42,7 +42,7 @@ working directory: fixtures/cli/tsgolint
   help: Remove the debugger statement
 
 Found 2 warnings and 2 errors.
-Finished in <variable>ms on 61 files with 2 rules using 1 threads.
+Finished in <variable>ms on 62 files with 2 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

apps/oxlint/src/snapshots/fixtures__cli__tsgolint_--type-aware test.svelte@oxlint.snap

@@ -16,7 +16,7 @@ working directory: fixtures/cli/tsgolint
   help: Remove the debugger statement
 
 Found 0 warnings and 1 error.
-Finished in <variable>ms on 1 file with 60 rules using 1 threads.
+Finished in <variable>ms on 1 file with 61 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

apps/oxlint/src/snapshots/fixtures__cli__tsgolint_--type-aware@oxlint.snap

@@ -352,6 +352,54 @@ working directory: fixtures/cli/tsgolint
  3 | 
    `----
 
+  x typescript(no-unsafe-enum-assignment): The value assigned here does not have a shared enum type with the expected enum 'Fruit'.
+   ,-[no-unsafe-enum-assignment.ts:6:7]
+ 5 | 
+ 6 | const fruit: Fruit = 1;
+   :       ^^^^^^^^^^^^^^^^
+ 7 | function takesFruit(value: Fruit): void {}
+   `----
+
+  x typescript(no-unsafe-enum-assignment): The argument passed here does not have a shared enum type with the expected enum 'Fruit'.
+   ,-[no-unsafe-enum-assignment.ts:8:12]
+ 7 | function takesFruit(value: Fruit): void {}
+ 8 | takesFruit(1);
+   :            ^
+ 9 | function getFruit(): Fruit {
+   `----
+
+  x typescript(no-unsafe-enum-assignment): The value returned here does not have a shared enum type with the expected enum 'Fruit'.
+    ,-[no-unsafe-enum-assignment.ts:10:3]
+  9 | function getFruit(): Fruit {
+ 10 |   return 0;
+    :   ^^^^^^^^^
+ 11 | }
+    `----
+
+  x typescript(no-unsafe-enum-assignment): The value asserted here does not have a shared enum type with the expected enum 'Fruit'.
+    ,-[no-unsafe-enum-assignment.ts:12:18]
+ 11 | }
+ 12 | const asserted = 1 as Fruit;
+    :                  ^^^^^^^^^^
+ 13 | let mutable = Fruit.Apple;
+    `----
+
+  x typescript(no-unsafe-enum-assignment): This mutation can produce a value outside of the expected enum 'Fruit'.
+    ,-[no-unsafe-enum-assignment.ts:14:1]
+ 13 | let mutable = Fruit.Apple;
+ 14 | mutable++;
+    : ^^^^^^^^^
+ 15 | declare const names: { [key in Fruit]: string };
+    `----
+
+  x typescript(no-unsafe-enum-assignment): The computed key used here does not have a shared enum type with the expected enum 'Fruit'.
+    ,-[no-unsafe-enum-assignment.ts:16:7]
+ 15 | declare const names: { [key in Fruit]: string };
+ 16 | names[0];
+    :       ^
+ 17 | 
+    `----
+
   x typescript(no-unsafe-enum-comparison): The two values in this comparison do not have a shared enum type.
     ,-[no-unsafe-enum-comparison.ts:9:20]
   8 | }
@@ -720,8 +768,8 @@ working directory: fixtures/cli/tsgolint
    `----
   help: If your function does not access `this`, you can annotate it with `this: void`, or consider using an arrow function instead.
 
-Found 0 warnings and 86 errors.
-Finished in <variable>ms on 61 files with 60 rules using 1 threads.
+Found 0 warnings and 92 errors.
+Finished in <variable>ms on 62 files with 61 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

apps/oxlint/src/snapshots/fixtures__cli__tsgolint_-c config-type-aware.json@oxlint.snap

@@ -42,7 +42,7 @@ working directory: fixtures/cli/tsgolint
   help: Remove the debugger statement
 
 Found 2 warnings and 2 errors.
-Finished in <variable>ms on 61 files with 2 rules using 1 threads.
+Finished in <variable>ms on 62 files with 2 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

crates/oxc_linter/src/generated/rule_runner_impls.rs

@@ -1972,6 +1972,11 @@ impl RuleRunner
     const RUN_FUNCTIONS: RuleRunFunctionsImplemented = RuleRunFunctionsImplemented::Run;
 }
 
+impl RuleRunner for crate::rules::typescript::no_unsafe_enum_assignment::NoUnsafeEnumAssignment {
+    const NODE_TYPES: Option<&AstTypesBitset> = None;
+    const RUN_FUNCTIONS: RuleRunFunctionsImplemented = RuleRunFunctionsImplemented::Unknown;
+}
+
 impl RuleRunner for crate::rules::typescript::no_unsafe_enum_comparison::NoUnsafeEnumComparison {
     const NODE_TYPES: Option<&AstTypesBitset> = None;
     const RUN_FUNCTIONS: RuleRunFunctionsImplemented = RuleRunFunctionsImplemented::Unknown;

crates/oxc_linter/src/rules.rs

@@ -299,6 +299,7 @@ pub(crate) mod typescript {
     pub mod no_unsafe_assignment;
     pub mod no_unsafe_call;
     pub mod no_unsafe_declaration_merging;
+    pub mod no_unsafe_enum_assignment;
     pub mod no_unsafe_enum_comparison;
     pub mod no_unsafe_function_type;
     pub mod no_unsafe_member_access;

crates/oxc_linter/src/rules/typescript/no_unsafe_enum_assignment.rs

@@ -0,0 +1,61 @@
+use oxc_macros::declare_oxc_lint;
+
+use crate::rule::Rule;
+
+#[derive(Debug, Default, Clone)]
+pub struct NoUnsafeEnumAssignment;
+
+declare_oxc_lint!(
+    /// ### What it does
+    ///
+    /// Disallows using values that do not share an enum type where an enum value is expected.
+    /// This includes assignments, arguments, return values, type assertions, mutations,
+    /// and computed keys in objects keyed by enum members.
+    ///
+    /// ### Why is this bad?
+    ///
+    /// Using the underlying number or string instead of an enum member bypasses the
+    /// enum's type safety. Numeric mutations can also produce values outside the enum.
+    /// Referencing enum members keeps values tied to the enum when its members change.
+    ///
+    /// ### Examples
+    ///
+    /// Examples of **incorrect** code for this rule:
+    /// ```ts
+    /// enum Fruit {
+    ///   Apple,
+    ///   Banana,
+    /// }
+    ///
+    /// const fruit: Fruit = 0;
+    /// function eat(fruit: Fruit) {}
+    /// eat(1);
+    ///
+    /// function getFruit(): Fruit {
+    ///   return 0;
+    /// }
+    /// ```
+    ///
+    /// Examples of **correct** code for this rule:
+    /// ```ts
+    /// enum Fruit {
+    ///   Apple,
+    ///   Banana,
+    /// }
+    ///
+    /// const fruit: Fruit = Fruit.Apple;
+    /// function eat(fruit: Fruit) {}
+    /// eat(Fruit.Banana);
+    ///
+    /// function getFruit(): Fruit {
+    ///   return Fruit.Apple;
+    /// }
+    /// ```
+    NoUnsafeEnumAssignment(tsgolint),
+    typescript,
+    suspicious,
+    version = "next",
+    short_description = "Disallow unsafe enum assignments.",
+);
+
+impl Rule for NoUnsafeEnumAssignment {}

npm/oxlint/configuration_schema.json

@@ -8371,6 +8371,9 @@
         "typescript/no-unsafe-declaration-merging": {
           "$ref": "#/definitions/RuleNoConfig"
         },
+        "typescript/no-unsafe-enum-assignment": {
+          "$ref": "#/definitions/RuleNoConfig"
+        },
         "typescript/no-unsafe-enum-comparison": {
           "$ref": "#/definitions/RuleNoConfig"
         },