Report unused locals in class static blocks

tsc/internal/checker/checker.go

@@ -2863,6 +2863,9 @@ func (c *Checker) checkClassStaticBlockDeclaration(node *ast.Node) {
 	// Grammar checking
 	c.checkGrammarModifiers(node)
 	node.ForEachChild(c.checkSourceElement)
+	if len(node.Locals()) != 0 {
+		c.registerForUnusedIdentifiersCheck(node)
+	}
 }
 
 func (c *Checker) checkConstructorDeclaration(node *ast.Node) {
@@ -7220,7 +7223,7 @@ func (c *Checker) checkUnusedIdentifiers(potentiallyUnusedIdentifiers []*ast.Nod
 			c.checkUnusedClassMembers(node)
 			c.checkUnusedTypeParameters(node)
 		case ast.KindSourceFile, ast.KindModuleDeclaration, ast.KindBlock, ast.KindCaseBlock, ast.KindForStatement, ast.KindForInStatement,
-			ast.KindForOfStatement:
+			ast.KindForOfStatement, ast.KindClassStaticBlockDeclaration:
 			c.checkUnusedLocalsAndParameters(node)
 		case ast.KindConstructor, ast.KindFunctionExpression, ast.KindFunctionDeclaration, ast.KindArrowFunction, ast.KindMethodDeclaration,
 			ast.KindGetAccessor, ast.KindSetAccessor:

tsc/testdata/baselines/reference/compiler/unusedLocalsAndParameters.errors.txt

@@ -19,13 +19,15 @@ unusedLocalsAndParameters.ts(71,11): error TS6133: 'c' is declared but its value
 unusedLocalsAndParameters.ts(74,11): error TS6133: 'c' is declared but its value is never read.
 unusedLocalsAndParameters.ts(79,11): error TS6133: 'N' is declared but its value is never read.
 unusedLocalsAndParameters.ts(80,9): error TS6133: 'x' is declared but its value is never read.
-unusedLocalsAndParameters.ts(83,13): error TS2304: Cannot find name 'y'.
-unusedLocalsAndParameters.ts(83,14): error TS1005: ',' expected.
-unusedLocalsAndParameters.ts(84,6): error TS1005: ',' expected.
-unusedLocalsAndParameters.ts(85,1): error TS1109: Expression expected.
+unusedLocalsAndParameters.ts(84,7): error TS6196: 'C1' is declared but never used.
+unusedLocalsAndParameters.ts(86,13): error TS6133: 'foo' is declared but its value is never read.
+unusedLocalsAndParameters.ts(90,13): error TS2304: Cannot find name 'y'.
+unusedLocalsAndParameters.ts(90,14): error TS1005: ',' expected.
+unusedLocalsAndParameters.ts(91,6): error TS1005: ',' expected.
+unusedLocalsAndParameters.ts(92,1): error TS1109: Expression expected.
 
 
-==== unusedLocalsAndParameters.ts (25 errors) ====
+==== unusedLocalsAndParameters.ts (27 errors) ====
     export { };
 
     // function declaration paramter
@@ -150,6 +152,17 @@ unusedLocalsAndParameters.ts(85,1): error TS1109: Expression expected.
 !!! error TS6133: 'x' is declared but its value is never read.
     }
 
+    // in a class static block
+    class C1 {
+          ~~
+!!! error TS6196: 'C1' is declared but never used.
+        static {
+            let foo = 1;
+                ~~~
+!!! error TS6133: 'foo' is declared but its value is never read.
+        }
+    }
+
     for (let x: y) {
                 ~
 !!! error TS2304: Cannot find name 'y'.

tsc/testdata/baselines/reference/compiler/unusedLocalsAndParameters.js

@@ -83,6 +83,13 @@ namespace N {
     var x;
 }
 
+// in a class static block
+class C1 {
+    static {
+        let foo = 1;
+    }
+}
+
 for (let x: y) {
     z(x);
 }
@@ -154,6 +161,12 @@ var N;
 (function (N) {
     var x;
 })(N || (N = {}));
+// in a class static block
+class C1 {
+}
+(() => {
+    let foo = 1;
+})();
 for (let x, { z }; (x); )
     ;
 export {};

tsc/testdata/baselines/reference/compiler/unusedLocalsAndParameters.symbols

@@ -133,12 +133,22 @@ namespace N {
 >x : Symbol(x, Decl(unusedLocalsAndParameters.ts, 79, 7))
 }
 
+// in a class static block
+class C1 {
+>C1 : Symbol(C1, Decl(unusedLocalsAndParameters.ts, 80, 1))
+
+    static {
+        let foo = 1;
+>foo : Symbol(foo, Decl(unusedLocalsAndParameters.ts, 85, 11))
+    }
+}
+
 for (let x: y) {
->x : Symbol(x, Decl(unusedLocalsAndParameters.ts, 82, 8))
+>x : Symbol(x, Decl(unusedLocalsAndParameters.ts, 89, 8))
 >y : Symbol(y)
 
     z(x);
->z : Symbol(z, Decl(unusedLocalsAndParameters.ts, 82, 16))
->x : Symbol(x, Decl(unusedLocalsAndParameters.ts, 82, 8))
+>z : Symbol(z, Decl(unusedLocalsAndParameters.ts, 89, 16))
+>x : Symbol(x, Decl(unusedLocalsAndParameters.ts, 89, 8))
 }
 

tsc/testdata/baselines/reference/compiler/unusedLocalsAndParameters.types

@@ -154,6 +154,17 @@ namespace N {
 >x : any
 }
 
+// in a class static block
+class C1 {
+>C1 : C1
+
+    static {
+        let foo = 1;
+>foo : number
+>1 : 1
+    }
+}
+
 for (let x: y) {
 >x : y
 

tsc/testdata/tests/cases/compiler/unusedLocalsAndParameters.ts

@@ -85,6 +85,13 @@ namespace N {
     var x;
 }
 
+// in a class static block
+class C1 {
+    static {
+        let foo = 1;
+    }
+}
+
 for (let x: y) {
     z(x);
 }