Port "Disallow type and interface declarations in statements with blockless bodies" (#1037)

Author: Andarist

internal/checker/checker.go

@@ -4704,6 +4704,9 @@ func (c *Checker) checkInterfaceDeclaration(node *ast.Node) {
 	if !c.checkGrammarModifiers(node) {
 		c.checkGrammarInterfaceDeclaration(node.AsInterfaceDeclaration())
 	}
+	if !c.containerAllowsBlockScopedVariable(node.Parent) {
+		c.grammarErrorOnNode(node, diagnostics.X_0_declarations_can_only_be_declared_inside_a_block, "interface")
+	}
 	c.checkTypeParameters(node.TypeParameters())
 	c.checkTypeNameIsReserved(node.Name(), diagnostics.Interface_name_cannot_be_0)
 	c.checkExportsOnMergedDeclarations(node)
@@ -6425,6 +6428,9 @@ func (c *Checker) checkTypeAliasDeclaration(node *ast.Node) {
 	// Grammar checking
 	c.checkGrammarModifiers(node)
 	c.checkTypeNameIsReserved(node.Name(), diagnostics.Type_alias_name_cannot_be_0)
+	if !c.containerAllowsBlockScopedVariable(node.Parent) {
+		c.grammarErrorOnNode(node, diagnostics.X_0_declarations_can_only_be_declared_inside_a_block, "type")
+	}
 	c.checkExportsOnMergedDeclarations(node)
 
 	typeNode := node.AsTypeAliasDeclaration().Type

testdata/baselines/reference/submodule/compiler/typeAliasDeclarationEmit3.errors.txt

@@ -0,0 +1,30 @@
+typeAliasDeclarationEmit3.ts(3,14): error TS1156: 'type' declarations can only be declared inside a block.
+typeAliasDeclarationEmit3.ts(9,14): error TS1156: 'type' declarations can only be declared inside a block.
+typeAliasDeclarationEmit3.ts(15,14): error TS1156: 'type' declarations can only be declared inside a block.
+
+
+==== typeAliasDeclarationEmit3.ts (3 errors) ====
+    function f1(): void {
+        for (let i = 0; i < 1; i++)
+            type foo = [];
+                 ~~~
+!!! error TS1156: 'type' declarations can only be declared inside a block.
+            console.log('f1');
+    }
+    
+    function f2(): void {
+        while (true)
+            type foo = [];
+                 ~~~
+!!! error TS1156: 'type' declarations can only be declared inside a block.
+            console.log('f2');
+    }
+    
+    function f3(): void {
+        if (true)
+            type foo = [];
+                 ~~~
+!!! error TS1156: 'type' declarations can only be declared inside a block.
+            console.log('f3');
+    }
+    

testdata/baselines/reference/submodule/compiler/typeAliasDeclarationEmit3.errors.txt.diff

@@ -1,12 +1,16 @@
+typeInterfaceDeclarationsInBlockStatements1.ts(4,18): error TS1156: 'type' declarations can only be declared inside a block.
 typeInterfaceDeclarationsInBlockStatements1.ts(12,21): error TS2304: Cannot find name 's'.
+typeInterfaceDeclarationsInBlockStatements1.ts(17,15): error TS1156: 'interface' declarations can only be declared inside a block.
 typeInterfaceDeclarationsInBlockStatements1.ts(29,21): error TS2304: Cannot find name 's'.
 
 
-==== typeInterfaceDeclarationsInBlockStatements1.ts (2 errors) ====
+==== typeInterfaceDeclarationsInBlockStatements1.ts (4 errors) ====
     // https://github.com/microsoft/TypeScript/issues/60175
 
     function f1() {
       if (true) type s = string;
+                     ~
+!!! error TS1156: 'type' declarations can only be declared inside a block.
       console.log("" as s);
     }
 
@@ -22,6 +26,8 @@ typeInterfaceDeclarationsInBlockStatements1.ts(29,21): error TS2304: Cannot find
     function f3() {
       if (true)
         interface s {
+                  ~
+!!! error TS1156: 'interface' declarations can only be declared inside a block.
           length: number;
         }
       console.log("" as s);