diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-async-function-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-async-function-declaration.template
new file mode 100644
index 0000000000..4a06bf44b8
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-async-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/async-function-declaration-attempt-to-
+name: AsyncFunctionDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-functions]
+---*/
+
+{ async function f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-async-generator-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-async-generator-declaration.template
new file mode 100644
index 0000000000..5327ac0fbe
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-async-generator-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/async-generator-declaration-attempt-to-
+name: AsyncGeneratorDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-iteration]
+---*/
+
+{ async function* f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-class-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-class-declaration.template
new file mode 100644
index 0000000000..0fd13ee658
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-class-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/class-declaration-attempt-to-
+name: ClassDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ class f {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-const-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-const-declaration.template
new file mode 100644
index 0000000000..0c9d092a8e
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-const-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/const-declaration-attempt-to-
+name: LexicalDeclaration (const) in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ const f = 0; /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-function-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-function-declaration.template
new file mode 100644
index 0000000000..bf954a75e7
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/function-declaration-attempt-to-
+name: FunctionDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [onlyStrict]
+---*/
+
+{ function f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-generator-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-generator-declaration.template
new file mode 100644
index 0000000000..f991d228a8
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-generator-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/generator-declaration-attempt-to-
+name: GeneratorDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ function* f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-let-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-let-declaration.template
new file mode 100644
index 0000000000..592556b0f9
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-let-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/let-declaration-attempt-to-
+name: LexicalDeclaration (let) in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ let f; /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-var-declaration.template b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-var-declaration.template
new file mode 100644
index 0000000000..50f548934e
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/block-attempt-to-redeclare-var-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/var-declaration-attempt-to-
+name: VariableDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ var f; /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-async-function-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-async-function-declaration.template
new file mode 100644
index 0000000000..57a185a7cc
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-async-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/async-function-declaration-attempt-to-
+name: AsyncFunctionDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-functions]
+---*/
+
+switch (0) { case 1: async function f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-async-generator-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-async-generator-declaration.template
new file mode 100644
index 0000000000..6d67152339
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-async-generator-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/async-generator-declaration-attempt-to-
+name: AsyncGeneratorDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-iteration]
+---*/
+
+switch (0) { case 1: async function* f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-class-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-class-declaration.template
new file mode 100644
index 0000000000..0e8888e4b8
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-class-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/class-declaration-attempt-to-
+name: ClassDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: class f {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-const-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-const-declaration.template
new file mode 100644
index 0000000000..9829abbf68
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-const-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/const-declaration-attempt-to-
+name: LexicalDeclaration (const) in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: const f = 0; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-function-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-function-declaration.template
new file mode 100644
index 0000000000..7ad3eede2a
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/function-declaration-attempt-to-
+name: FunctionDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [onlyStrict]
+---*/
+
+switch (0) { case 1: function f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-generator-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-generator-declaration.template
new file mode 100644
index 0000000000..5fb499613f
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-generator-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/generator-declaration-attempt-to-
+name: GeneratorDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: function* f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-let-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-let-declaration.template
new file mode 100644
index 0000000000..f11a6dc158
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-let-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/let-declaration-attempt-to-
+name: LexicalDeclaration (let) in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: let f; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-var-declaration.template b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-var-declaration.template
new file mode 100644
index 0000000000..dd83e6bcd2
--- /dev/null
+++ b/src/declarations/redeclare-allow-sloppy-function/switch-attempt-to-redeclare-var-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/var-declaration-attempt-to-
+name: VariableDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: var f; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-async-function-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-async-function-declaration.template
new file mode 100644
index 0000000000..2349e07a3d
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-async-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/async-function-declaration-attempt-to-
+name: AsyncFunctionDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-functions]
+---*/
+
+{ async function f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-async-generator-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-async-generator-declaration.template
new file mode 100644
index 0000000000..ed2adc2d6c
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-async-generator-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/async-generator-declaration-attempt-to-
+name: AsyncGeneratorDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-iteration]
+---*/
+
+{ async function* f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-class-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-class-declaration.template
new file mode 100644
index 0000000000..4cadafbd71
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-class-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/class-declaration-attempt-to-
+name: ClassDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ class f {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-const-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-const-declaration.template
new file mode 100644
index 0000000000..711fdf4225
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-const-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/const-declaration-attempt-to-
+name: LexicalDeclaration (const) in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ const f = 0; /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-function-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-function-declaration.template
new file mode 100644
index 0000000000..9e8ee15f50
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-function-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/function-declaration-attempt-to-
+name: FunctionDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ function f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-generator-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-generator-declaration.template
new file mode 100644
index 0000000000..f4a49b40c1
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-generator-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/generator-declaration-attempt-to-
+name: GeneratorDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ function* f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-let-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-let-declaration.template
new file mode 100644
index 0000000000..57f5bebe99
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-let-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/let-declaration-attempt-to-
+name: LexicalDeclaration (let) in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ let f; /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-var-declaration.template b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-var-declaration.template
new file mode 100644
index 0000000000..cdb73b1e4a
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/block-attempt-to-redeclare-var-declaration.template
@@ -0,0 +1,15 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/var-declaration-attempt-to-
+name: VariableDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+---*/
+
+{ var f; /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-async-function-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-async-function-declaration.template
new file mode 100644
index 0000000000..6317cd26f0
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-async-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/async-function-declaration-attempt-to-
+name: AsyncFunctionDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-functions]
+---*/
+
+switch (0) { case 1: async function f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-async-generator-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-async-generator-declaration.template
new file mode 100644
index 0000000000..7b8c6b0b92
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-async-generator-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/async-generator-declaration-attempt-to-
+name: AsyncGeneratorDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-iteration]
+---*/
+
+switch (0) { case 1: async function* f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-class-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-class-declaration.template
new file mode 100644
index 0000000000..2462d78ede
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-class-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/class-declaration-attempt-to-
+name: ClassDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: class f {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-const-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-const-declaration.template
new file mode 100644
index 0000000000..8361a53a78
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-const-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/const-declaration-attempt-to-
+name: LexicalDeclaration (const) in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: const f = 0; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-function-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-function-declaration.template
new file mode 100644
index 0000000000..12da4af5c2
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-function-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/function-declaration-attempt-to-
+name: FunctionDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: function f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-generator-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-generator-declaration.template
new file mode 100644
index 0000000000..029076ae5b
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-generator-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/generator-declaration-attempt-to-
+name: GeneratorDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: function* f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-let-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-let-declaration.template
new file mode 100644
index 0000000000..18fb61d17e
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-let-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/let-declaration-attempt-to-
+name: LexicalDeclaration (let) in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: let f; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-var-declaration.template b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-var-declaration.template
new file mode 100644
index 0000000000..462c5647c0
--- /dev/null
+++ b/src/declarations/redeclare-allow-var/switch-attempt-to-redeclare-var-declaration.template
@@ -0,0 +1,15 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/var-declaration-attempt-to-
+name: VariableDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+---*/
+
+switch (0) { case 1: var f; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare-with-async-function-declaration.case b/src/declarations/redeclare-with-async-function-declaration.case
new file mode 100644
index 0000000000..cf74b701d3
--- /dev/null
+++ b/src/declarations/redeclare-with-async-function-declaration.case
@@ -0,0 +1,12 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with AsyncFunctionDeclaration
+template: redeclare
+flags: [async-functions]
+---*/
+
+//- body
+  async function f() {}
diff --git a/src/declarations/redeclare-with-async-generator-declaration.case b/src/declarations/redeclare-with-async-generator-declaration.case
new file mode 100644
index 0000000000..7f2638d2a1
--- /dev/null
+++ b/src/declarations/redeclare-with-async-generator-declaration.case
@@ -0,0 +1,12 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with AsyncGeneratorDeclaration
+template: redeclare
+flags: [async-iteration]
+---*/
+
+//- body
+  async function* f() {}
diff --git a/src/declarations/redeclare-with-class-declaration.case b/src/declarations/redeclare-with-class-declaration.case
new file mode 100644
index 0000000000..96d73ad4fe
--- /dev/null
+++ b/src/declarations/redeclare-with-class-declaration.case
@@ -0,0 +1,11 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with ClassDeclaration
+template: redeclare
+---*/
+
+//- body
+  class f {};
diff --git a/src/declarations/redeclare-with-const-declaration.case b/src/declarations/redeclare-with-const-declaration.case
new file mode 100644
index 0000000000..0ca9e32c84
--- /dev/null
+++ b/src/declarations/redeclare-with-const-declaration.case
@@ -0,0 +1,11 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with const-LexicalDeclaration
+template: redeclare
+---*/
+
+//- body
+  const f = 0;
diff --git a/src/declarations/redeclare-with-function-declaration.case b/src/declarations/redeclare-with-function-declaration.case
new file mode 100644
index 0000000000..2924d17d9d
--- /dev/null
+++ b/src/declarations/redeclare-with-function-declaration.case
@@ -0,0 +1,11 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with FunctionDeclaration
+template: redeclare-allow-sloppy-function
+---*/
+
+//- body
+  function f() {}
diff --git a/src/declarations/redeclare-with-generator-declaration.case b/src/declarations/redeclare-with-generator-declaration.case
new file mode 100644
index 0000000000..91b8398bc7
--- /dev/null
+++ b/src/declarations/redeclare-with-generator-declaration.case
@@ -0,0 +1,11 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with GeneratorDeclaration
+template: redeclare
+---*/
+
+//- body
+  function* f() {}
diff --git a/src/declarations/redeclare-with-let-declaration.case b/src/declarations/redeclare-with-let-declaration.case
new file mode 100644
index 0000000000..f20d89ec39
--- /dev/null
+++ b/src/declarations/redeclare-with-let-declaration.case
@@ -0,0 +1,11 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with let-LexicalDeclaration
+template: redeclare
+---*/
+
+//- body
+  let f;
diff --git a/src/declarations/redeclare-with-var-declaration.case b/src/declarations/redeclare-with-var-declaration.case
new file mode 100644
index 0000000000..e4c493e805
--- /dev/null
+++ b/src/declarations/redeclare-with-var-declaration.case
@@ -0,0 +1,11 @@
+// Copyright (C) André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+desc: >
+  redeclaration with VariableDeclaration
+template: redeclare-allow-var
+---*/
+
+//- body
+  var f;
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-async-function-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-async-function-declaration.template
new file mode 100644
index 0000000000..4a06bf44b8
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-async-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/async-function-declaration-attempt-to-
+name: AsyncFunctionDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-functions]
+---*/
+
+{ async function f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-async-generator-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-async-generator-declaration.template
new file mode 100644
index 0000000000..5327ac0fbe
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-async-generator-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/async-generator-declaration-attempt-to-
+name: AsyncGeneratorDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-iteration]
+---*/
+
+{ async function* f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-class-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-class-declaration.template
new file mode 100644
index 0000000000..0fd13ee658
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-class-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/class-declaration-attempt-to-
+name: ClassDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ class f {} /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-const-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-const-declaration.template
new file mode 100644
index 0000000000..0c9d092a8e
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-const-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/const-declaration-attempt-to-
+name: LexicalDeclaration (const) in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ const f = 0; /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-function-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-function-declaration.template
new file mode 100644
index 0000000000..f163125379
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-function-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/function-declaration-attempt-to-
+name: FunctionDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ function f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-generator-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-generator-declaration.template
new file mode 100644
index 0000000000..f991d228a8
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-generator-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/generator-declaration-attempt-to-
+name: GeneratorDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ function* f() {} /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-let-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-let-declaration.template
new file mode 100644
index 0000000000..592556b0f9
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-let-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/let-declaration-attempt-to-
+name: LexicalDeclaration (let) in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if the LexicallyDeclaredNames of StatementList contains
+  any duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ let f; /*{ body }*/ }
diff --git a/src/declarations/redeclare/block-attempt-to-redeclare-var-declaration.template b/src/declarations/redeclare/block-attempt-to-redeclare-var-declaration.template
new file mode 100644
index 0000000000..50f548934e
--- /dev/null
+++ b/src/declarations/redeclare/block-attempt-to-redeclare-var-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/block-scope/syntax/redeclaration/var-declaration-attempt-to-
+name: VariableDeclaration in BlockStatement
+esid: sec-block-static-semantics-early-errors
+info: |
+  Block : { StatementList }
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  StatementList also occurs in the VarDeclaredNames of StatementList.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+{ var f; /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-async-function-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-async-function-declaration.template
new file mode 100644
index 0000000000..57a185a7cc
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-async-function-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/async-function-declaration-attempt-to-
+name: AsyncFunctionDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-functions]
+---*/
+
+switch (0) { case 1: async function f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-async-generator-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-async-generator-declaration.template
new file mode 100644
index 0000000000..6d67152339
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-async-generator-declaration.template
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/async-generator-declaration-attempt-to-
+name: AsyncGeneratorDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+flags: [async-iteration]
+---*/
+
+switch (0) { case 1: async function* f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-class-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-class-declaration.template
new file mode 100644
index 0000000000..0e8888e4b8
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-class-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/class-declaration-attempt-to-
+name: ClassDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: class f {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-const-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-const-declaration.template
new file mode 100644
index 0000000000..9829abbf68
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-const-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/const-declaration-attempt-to-
+name: LexicalDeclaration (const) in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: const f = 0; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-function-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-function-declaration.template
new file mode 100644
index 0000000000..25e21f00b0
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-function-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/function-declaration-attempt-to-
+name: FunctionDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: function f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-generator-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-generator-declaration.template
new file mode 100644
index 0000000000..5fb499613f
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-generator-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/generator-declaration-attempt-to-
+name: GeneratorDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: function* f() {} default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-let-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-let-declaration.template
new file mode 100644
index 0000000000..f11a6dc158
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-let-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/let-declaration-attempt-to-
+name: LexicalDeclaration (let) in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if the LexicallyDeclaredNames of CaseBlock contains any
+  duplicate entries.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: let f; default: /*{ body }*/ }
diff --git a/src/declarations/redeclare/switch-attempt-to-redeclare-var-declaration.template b/src/declarations/redeclare/switch-attempt-to-redeclare-var-declaration.template
new file mode 100644
index 0000000000..dd83e6bcd2
--- /dev/null
+++ b/src/declarations/redeclare/switch-attempt-to-redeclare-var-declaration.template
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+path: language/statements/switch/syntax/redeclaration/var-declaration-attempt-to-
+name: VariableDeclaration in SwitchStatement
+esid: sec-switch-statement-static-semantics-early-errors
+info: |
+  SwitchStatement : switch ( Expression ) CaseBlock
+
+  It is a Syntax Error if any element of the LexicallyDeclaredNames of
+  CaseBlock also occurs in the VarDeclaredNames of CaseBlock.
+negative:
+  phase: early
+  type: SyntaxError
+---*/
+
+switch (0) { case 1: var f; default: /*{ body }*/ }