Move tests into anonymous namespace.

This CL moves all test files to the anonymous namespace.

Change-Id: Ie5ae0efe907c03eeb441e90f31c976844172b594
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/17900
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
diff --git a/src/ast/array_accessor_expression_test.cc b/src/ast/array_accessor_expression_test.cc
index 51b41e3..833e46f 100644
--- a/src/ast/array_accessor_expression_test.cc
+++ b/src/ast/array_accessor_expression_test.cc
@@ -19,6 +19,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ArrayAccessorExpressionTest = testing::Test;
 
@@ -101,5 +102,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/as_expression_test.cc b/src/ast/as_expression_test.cc
index c49942d3..e41c0ba 100644
--- a/src/ast/as_expression_test.cc
+++ b/src/ast/as_expression_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using AsExpressionTest = testing::Test;
 
@@ -94,5 +95,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/assignment_statement_test.cc b/src/ast/assignment_statement_test.cc
index 132ee6f..f8959e3 100644
--- a/src/ast/assignment_statement_test.cc
+++ b/src/ast/assignment_statement_test.cc
@@ -19,6 +19,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using AssignmentStatementTest = testing::Test;
 
@@ -105,5 +106,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/binding_decoration_test.cc b/src/ast/binding_decoration_test.cc
index fffb329..71fefdf 100644
--- a/src/ast/binding_decoration_test.cc
+++ b/src/ast/binding_decoration_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using BindingDecorationTest = testing::Test;
 
@@ -42,5 +43,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/bool_literal_test.cc b/src/ast/bool_literal_test.cc
index af01dae..190a51b 100644
--- a/src/ast/bool_literal_test.cc
+++ b/src/ast/bool_literal_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using BoolLiteralTest = testing::Test;
 
@@ -51,5 +52,6 @@
   EXPECT_EQ(f.to_str(), "false");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/break_statement_test.cc b/src/ast/break_statement_test.cc
index 34305a1..87ace59 100644
--- a/src/ast/break_statement_test.cc
+++ b/src/ast/break_statement_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using BreakStatementTest = testing::Test;
 
@@ -109,5 +110,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/builtin_decoration_test.cc b/src/ast/builtin_decoration_test.cc
index 266edc1..114874b 100644
--- a/src/ast/builtin_decoration_test.cc
+++ b/src/ast/builtin_decoration_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using BuiltinDecorationTest = testing::Test;
 
@@ -42,5 +43,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/call_expression_test.cc b/src/ast/call_expression_test.cc
index b4dad2f..1425f06 100644
--- a/src/ast/call_expression_test.cc
+++ b/src/ast/call_expression_test.cc
@@ -19,6 +19,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using CallExpressionTest = testing::Test;
 
@@ -127,5 +128,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/case_statement_test.cc b/src/ast/case_statement_test.cc
index 9395b52..dc1f90b 100644
--- a/src/ast/case_statement_test.cc
+++ b/src/ast/case_statement_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using CaseStatementTest = testing::Test;
 
@@ -121,5 +122,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/cast_expression_test.cc b/src/ast/cast_expression_test.cc
index 711918e..d7f9498 100644
--- a/src/ast/cast_expression_test.cc
+++ b/src/ast/cast_expression_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using CastExpressionTest = testing::Test;
 
@@ -92,5 +93,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/const_initializer_expression_test.cc b/src/ast/const_initializer_expression_test.cc
index 9098a0c..a823a33 100644
--- a/src/ast/const_initializer_expression_test.cc
+++ b/src/ast/const_initializer_expression_test.cc
@@ -19,6 +19,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ConstInitializerExpressionTest = testing::Test;
 
@@ -57,5 +58,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/continue_statement_test.cc b/src/ast/continue_statement_test.cc
index 366bb4d..5f4a88c 100644
--- a/src/ast/continue_statement_test.cc
+++ b/src/ast/continue_statement_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ContinueStatementTest = testing::Test;
 
@@ -109,5 +110,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/decorated_variable_test.cc b/src/ast/decorated_variable_test.cc
index e2ed800..fd4ad62 100644
--- a/src/ast/decorated_variable_test.cc
+++ b/src/ast/decorated_variable_test.cc
@@ -25,6 +25,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using DecoratedVariableTest = testing::Test;
 
@@ -93,5 +94,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/else_statement_test.cc b/src/ast/else_statement_test.cc
index b9c5f1b..9675e0b 100644
--- a/src/ast/else_statement_test.cc
+++ b/src/ast/else_statement_test.cc
@@ -22,6 +22,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ElseStatementTest = testing::Test;
 
@@ -135,5 +136,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/entry_point_test.cc b/src/ast/entry_point_test.cc
index 3d8a1b5..2dfb0b8 100644
--- a/src/ast/entry_point_test.cc
+++ b/src/ast/entry_point_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using EntryPointTest = testing::Test;
 
@@ -95,5 +96,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/fallthrough_statement_test.cc b/src/ast/fallthrough_statement_test.cc
index 0d397d1..632b940 100644
--- a/src/ast/fallthrough_statement_test.cc
+++ b/src/ast/fallthrough_statement_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using FallthroughStatementTest = testing::Test;
 
@@ -52,5 +53,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/float_literal_test.cc b/src/ast/float_literal_test.cc
index 8274761..e9b3f4e 100644
--- a/src/ast/float_literal_test.cc
+++ b/src/ast/float_literal_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using FloatLiteralTest = testing::Test;
 
@@ -41,5 +42,6 @@
   EXPECT_EQ(f.to_str(), "42.1");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/function_test.cc b/src/ast/function_test.cc
index e4506a5..0e9e2bf 100644
--- a/src/ast/function_test.cc
+++ b/src/ast/function_test.cc
@@ -23,6 +23,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using FunctionTest = testing::Test;
 
@@ -225,5 +226,6 @@
   EXPECT_EQ(f.type_name(), "__func__void__i32__f32");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/identifier_expression_test.cc b/src/ast/identifier_expression_test.cc
index ddbefd2..3252ab3 100644
--- a/src/ast/identifier_expression_test.cc
+++ b/src/ast/identifier_expression_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using IdentifierExpressionTest = testing::Test;
 
@@ -80,5 +81,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/if_statement_test.cc b/src/ast/if_statement_test.cc
index e9990af..6d6abd4 100644
--- a/src/ast/if_statement_test.cc
+++ b/src/ast/if_statement_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using IfStatementTest = testing::Test;
 
@@ -361,5 +362,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/import_test.cc b/src/ast/import_test.cc
index 48f5a77..0bde102 100644
--- a/src/ast/import_test.cc
+++ b/src/ast/import_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ImportTest = testing::Test;
 
@@ -87,5 +88,6 @@
   EXPECT_FALSE(i.IsValid());
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/int_literal_test.cc b/src/ast/int_literal_test.cc
index 7b7fe86..8d35d5d 100644
--- a/src/ast/int_literal_test.cc
+++ b/src/ast/int_literal_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using IntLiteralTest = testing::Test;
 
@@ -41,5 +42,6 @@
   EXPECT_EQ(i.to_str(), "-42");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/kill_statement_test.cc b/src/ast/kill_statement_test.cc
index 63115c7..e75988a 100644
--- a/src/ast/kill_statement_test.cc
+++ b/src/ast/kill_statement_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using KillStatementTest = testing::Test;
 
@@ -53,5 +54,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/location_decoration_test.cc b/src/ast/location_decoration_test.cc
index c68253a..a5340e8 100644
--- a/src/ast/location_decoration_test.cc
+++ b/src/ast/location_decoration_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using LocationDecorationTest = testing::Test;
 
@@ -44,5 +45,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/loop_statement_test.cc b/src/ast/loop_statement_test.cc
index 09455da..37788d5 100644
--- a/src/ast/loop_statement_test.cc
+++ b/src/ast/loop_statement_test.cc
@@ -23,6 +23,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using LoopStatementTest = testing::Test;
 
@@ -183,5 +184,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/member_accessor_expression_test.cc b/src/ast/member_accessor_expression_test.cc
index 57e30be..f42110b 100644
--- a/src/ast/member_accessor_expression_test.cc
+++ b/src/ast/member_accessor_expression_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using MemberAccessorExpressionTest = testing::Test;
 
@@ -105,5 +106,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/module_test.cc b/src/ast/module_test.cc
index 7fad54b..2742bd4 100644
--- a/src/ast/module_test.cc
+++ b/src/ast/module_test.cc
@@ -26,6 +26,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ModuleTest = testing::Test;
 
@@ -184,5 +185,6 @@
   EXPECT_FALSE(m.IsValid());
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/nop_statement_test.cc b/src/ast/nop_statement_test.cc
index 7f47b28..502622d 100644
--- a/src/ast/nop_statement_test.cc
+++ b/src/ast/nop_statement_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using NopStatementTest = testing::Test;
 
@@ -53,5 +54,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/regardless_statement_test.cc b/src/ast/regardless_statement_test.cc
index 4c34bdb..cf15f1f 100644
--- a/src/ast/regardless_statement_test.cc
+++ b/src/ast/regardless_statement_test.cc
@@ -23,6 +23,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using RegardlessStatementTest = testing::Test;
 
@@ -122,5 +123,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/relational_expression_test.cc b/src/ast/relational_expression_test.cc
index ff41032..b014448 100644
--- a/src/ast/relational_expression_test.cc
+++ b/src/ast/relational_expression_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using RelationalExpressionTest = testing::Test;
 
@@ -118,5 +119,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/return_statement_test.cc b/src/ast/return_statement_test.cc
index ebbcaab..3cd4a04 100644
--- a/src/ast/return_statement_test.cc
+++ b/src/ast/return_statement_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using ReturnStatementTest = testing::Test;
 
@@ -93,5 +94,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/set_decoration_test.cc b/src/ast/set_decoration_test.cc
index b257453..9b70c4e 100644
--- a/src/ast/set_decoration_test.cc
+++ b/src/ast/set_decoration_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using SetDecorationTest = testing::Test;
 
@@ -42,5 +43,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/struct_member_offset_decoration_test.cc b/src/ast/struct_member_offset_decoration_test.cc
index cd2e2b9..a73b367 100644
--- a/src/ast/struct_member_offset_decoration_test.cc
+++ b/src/ast/struct_member_offset_decoration_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using StructMemberOffsetDecorationTest = testing::Test;
 
@@ -31,5 +32,6 @@
   EXPECT_TRUE(d.IsOffset());
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/struct_member_test.cc b/src/ast/struct_member_test.cc
index cbe4ef9..c164959 100644
--- a/src/ast/struct_member_test.cc
+++ b/src/ast/struct_member_test.cc
@@ -23,6 +23,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using StructMemberTest = testing::Test;
 
@@ -98,5 +99,6 @@
   EXPECT_EQ(out.str(), "  StructMember{a: __i32}\n");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/struct_test.cc b/src/ast/struct_test.cc
index 35d608d..b214525 100644
--- a/src/ast/struct_test.cc
+++ b/src/ast/struct_test.cc
@@ -24,6 +24,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using StructTest = testing::Test;
 
@@ -97,5 +98,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/switch_statement_test.cc b/src/ast/switch_statement_test.cc
index 209f7da..1f065ec 100644
--- a/src/ast/switch_statement_test.cc
+++ b/src/ast/switch_statement_test.cc
@@ -23,6 +23,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using SwitchStatementTest = testing::Test;
 
@@ -150,5 +151,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/alias_type_test.cc b/src/ast/type/alias_type_test.cc
index e3c3126..38d05b6 100644
--- a/src/ast/type/alias_type_test.cc
+++ b/src/ast/type/alias_type_test.cc
@@ -21,6 +21,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using AliasTypeTest = testing::Test;
 
@@ -53,6 +54,7 @@
   EXPECT_EQ(at.type_name(), "__alias_Particle__i32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/array_type_test.cc b/src/ast/type/array_type_test.cc
index 5495f5b..4751641 100644
--- a/src/ast/type/array_type_test.cc
+++ b/src/ast/type/array_type_test.cc
@@ -21,6 +21,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using ArrayTypeTest = testing::Test;
 
@@ -64,6 +65,7 @@
   EXPECT_EQ(arr.type_name(), "__array__i32_3");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/bool_type_test.cc b/src/ast/type/bool_type_test.cc
index 6aacfe8..55e406d 100644
--- a/src/ast/type/bool_type_test.cc
+++ b/src/ast/type/bool_type_test.cc
@@ -19,6 +19,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using BoolTypeTest = testing::Test;
 
@@ -41,6 +42,7 @@
   EXPECT_EQ(b.type_name(), "__bool");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/f32_type_test.cc b/src/ast/type/f32_type_test.cc
index a5287f0..1717956 100644
--- a/src/ast/type/f32_type_test.cc
+++ b/src/ast/type/f32_type_test.cc
@@ -19,6 +19,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using F32TypeTest = testing::Test;
 
@@ -41,6 +42,7 @@
   EXPECT_EQ(f.type_name(), "__f32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/i32_type_test.cc b/src/ast/type/i32_type_test.cc
index 67f2483..7697fc7 100644
--- a/src/ast/type/i32_type_test.cc
+++ b/src/ast/type/i32_type_test.cc
@@ -19,6 +19,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using I32TypeTest = testing::Test;
 
@@ -41,6 +42,7 @@
   EXPECT_EQ(i.type_name(), "__i32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/matrix_type_test.cc b/src/ast/type/matrix_type_test.cc
index 0bdb7ea..1babb7d 100644
--- a/src/ast/type/matrix_type_test.cc
+++ b/src/ast/type/matrix_type_test.cc
@@ -20,6 +20,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using MatrixTypeTest = testing::Test;
 
@@ -52,6 +53,7 @@
   EXPECT_EQ(m.type_name(), "__mat_2_3__i32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/pointer_type_test.cc b/src/ast/type/pointer_type_test.cc
index 52d167f..8889cb8 100644
--- a/src/ast/type/pointer_type_test.cc
+++ b/src/ast/type/pointer_type_test.cc
@@ -20,6 +20,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using PointerTypeTest = testing::Test;
 
@@ -51,6 +52,7 @@
   EXPECT_EQ(p.type_name(), "__ptr_workgroup__i32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/struct_type_test.cc b/src/ast/type/struct_type_test.cc
index 1721079..6492a15 100644
--- a/src/ast/type/struct_type_test.cc
+++ b/src/ast/type/struct_type_test.cc
@@ -22,6 +22,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using StructTypeTest = testing::Test;
 
@@ -54,6 +55,7 @@
   EXPECT_EQ(s.type_name(), "__struct_my_struct");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/u32_type_test.cc b/src/ast/type/u32_type_test.cc
index 5f4508e..eb875b4 100644
--- a/src/ast/type/u32_type_test.cc
+++ b/src/ast/type/u32_type_test.cc
@@ -19,6 +19,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using U32TypeTest = testing::Test;
 
@@ -41,6 +42,7 @@
   EXPECT_EQ(u.type_name(), "__u32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type/vector_type_test.cc b/src/ast/type/vector_type_test.cc
index bc08383..cd2ce3a 100644
--- a/src/ast/type/vector_type_test.cc
+++ b/src/ast/type/vector_type_test.cc
@@ -20,6 +20,7 @@
 namespace tint {
 namespace ast {
 namespace type {
+namespace {
 
 using VectorTypeTest = testing::Test;
 
@@ -51,6 +52,7 @@
   EXPECT_EQ(v.type_name(), "__vec_3__i32");
 }
 
+}  // namespace
 }  // namespace type
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/type_initializer_expression_test.cc b/src/ast/type_initializer_expression_test.cc
index 96b8c30..80c5f98 100644
--- a/src/ast/type_initializer_expression_test.cc
+++ b/src/ast/type_initializer_expression_test.cc
@@ -23,6 +23,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using TypeInitializerExpressionTest = testing::Test;
 
@@ -119,5 +120,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/uint_literal_test.cc b/src/ast/uint_literal_test.cc
index 04628c3..137cded 100644
--- a/src/ast/uint_literal_test.cc
+++ b/src/ast/uint_literal_test.cc
@@ -18,6 +18,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using UintLiteralTest = testing::Test;
 
@@ -41,5 +42,6 @@
   EXPECT_EQ(i.to_str(), "42");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/unary_derivative_expression_test.cc b/src/ast/unary_derivative_expression_test.cc
index 17f43b3..6a9d366 100644
--- a/src/ast/unary_derivative_expression_test.cc
+++ b/src/ast/unary_derivative_expression_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using UnaryDerivativeExpressionTest = testing::Test;
 
@@ -84,5 +85,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/unary_method_expression_test.cc b/src/ast/unary_method_expression_test.cc
index 7f0b46d..2d51e63 100644
--- a/src/ast/unary_method_expression_test.cc
+++ b/src/ast/unary_method_expression_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using UnaryMethodExpressionTest = testing::Test;
 
@@ -96,5 +97,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/unary_op_expression_test.cc b/src/ast/unary_op_expression_test.cc
index fef07d5..93462bb 100644
--- a/src/ast/unary_op_expression_test.cc
+++ b/src/ast/unary_op_expression_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using UnaryOpExpressionTest = testing::Test;
 
@@ -76,5 +77,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/unless_statement_test.cc b/src/ast/unless_statement_test.cc
index d4f644f..5cb9443 100644
--- a/src/ast/unless_statement_test.cc
+++ b/src/ast/unless_statement_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using UnlessStatementTest = testing::Test;
 
@@ -120,5 +121,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/variable_statement_test.cc b/src/ast/variable_statement_test.cc
index a7b56c1..5bc0eb7 100644
--- a/src/ast/variable_statement_test.cc
+++ b/src/ast/variable_statement_test.cc
@@ -20,6 +20,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using VariableStatementTest = testing::Test;
 
@@ -83,5 +84,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint
diff --git a/src/ast/variable_test.cc b/src/ast/variable_test.cc
index 26dc5152..1a33e3f 100644
--- a/src/ast/variable_test.cc
+++ b/src/ast/variable_test.cc
@@ -21,6 +21,7 @@
 
 namespace tint {
 namespace ast {
+namespace {
 
 using VariableTest = testing::Test;
 
@@ -113,5 +114,6 @@
 )");
 }
 
+}  // namespace
 }  // namespace ast
 }  // namespace tint