feat(linter): add typescript/no-unnecessary-qualifier rule

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

@@ -19,6 +19,7 @@
     "typescript/no-redundant-type-constituents": "error",
     "typescript/no-unnecessary-boolean-literal-compare": "error",
     "typescript/no-unnecessary-condition": "error",
+    "typescript/no-unnecessary-qualifier": "error",
     "typescript/no-unnecessary-template-expression": "error",
     "typescript/no-unnecessary-type-arguments": "error",
     "typescript/no-unnecessary-type-assertion": "error",

apps/oxlint/fixtures/tsgolint/no-unnecessary-qualifier.ts

@@ -0,0 +1,6 @@
+// Examples of incorrect code for no-unnecessary-qualifier rule
+
+namespace A {
+  export type B = number;
+  const x: A.B = 3;
+}

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

@@ -6,8 +6,8 @@ arguments: --type-aware --silent
 working directory: fixtures/tsgolint
 ----------
 
-Found 0 warnings and 62 errors.
-Finished in <variable>ms on 51 files with 50 rules using 1 threads.
+Found 0 warnings and 63 errors.
+Finished in <variable>ms on 52 files with 51 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

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

@@ -40,7 +40,7 @@ working directory: fixtures/tsgolint
   help: Remove the debugger statement
 
 Found 2 warnings and 2 errors.
-Finished in <variable>ms on 51 files with 1 rules using 1 threads.
+Finished in <variable>ms on 52 files with 1 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

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

@@ -16,7 +16,7 @@ working directory: fixtures/tsgolint
   help: Remove the debugger statement
 
 Found 0 warnings and 1 error.
-Finished in <variable>ms on 1 file with 50 rules using 1 threads.
+Finished in <variable>ms on 1 file with 51 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

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

@@ -158,6 +158,14 @@ working directory: fixtures/tsgolint
    :                   ^^
    `----
 
+  x typescript-eslint(no-unnecessary-qualifier): Qualifier is unnecessary since 'B' is in scope.
+   ,-[no-unnecessary-qualifier.ts:5:12]
+ 4 |   export type B = number;
+ 5 |   const x: A.B = 3;
+   :            ^
+ 6 | }
+   `----
+
   x typescript-eslint(no-unnecessary-template-expression): Template literal expression is unnecessary and can be simplified.
    ,-[no-unnecessary-template-expression.ts:2:18]
  1 | const text = 'hello';
@@ -486,8 +494,8 @@ working directory: fixtures/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 62 errors.
-Finished in <variable>ms on 51 files with 50 rules using 1 threads.
+Found 0 warnings and 63 errors.
+Finished in <variable>ms on 52 files with 51 rules using 1 threads.
 ----------
 CLI result: LintFoundErrors
 ----------

crates/oxc_linter/src/rules.rs

@@ -262,6 +262,7 @@ pub(crate) mod typescript {
     pub mod no_unnecessary_boolean_literal_compare;
     pub mod no_unnecessary_condition;
     pub mod no_unnecessary_parameter_property_assignment;
+    pub mod no_unnecessary_qualifier;
     pub mod no_unnecessary_template_expression;
     pub mod no_unnecessary_type_arguments;
     pub mod no_unnecessary_type_assertion;

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

@@ -0,0 +1,39 @@
+use oxc_macros::declare_oxc_lint;
+
+use crate::rule::Rule;
+
+#[derive(Debug, Default, Clone)]
+pub struct NoUnnecessaryQualifier;
+
+declare_oxc_lint!(
+    /// ### What it does
+    ///
+    /// Disallow namespace qualifiers when the referenced name is already in scope.
+    ///
+    /// ### Why is this bad?
+    ///
+    /// Redundant qualifiers add noise and make type references harder to read.
+    ///
+    /// ### Examples
+    ///
+    /// Examples of **incorrect** code for this rule:
+    /// ```ts
+    /// namespace A {
+    ///   export type B = number;
+    ///   const value: A.B = 1;
+    /// }
+    /// ```
+    ///
+    /// Examples of **correct** code for this rule:
+    /// ```ts
+    /// namespace A {
+    ///   export type B = number;
+    ///   const value: B = 1;
+    /// }
+    /// ```
+    NoUnnecessaryQualifier(tsgolint),
+    typescript,
+    nursery,
+);
+
+impl Rule for NoUnnecessaryQualifier {}