[clang] [clang-format] Add new option: WrapNamespaceBodyWithNewlines (PR #106145)

[Owen Pan via cfe-commits]

================
@@ -28104,6 +28104,253 @@ TEST_F(FormatTest, BreakBinaryOperations) {
                Style);
 }
 
+TEST_F(FormatTest, WrapNamespaceBodyWithEmptyLinesNever) {
+  FormatStyle Style = getLLVMStyle();
+  Style.FixNamespaceComments = false;
+  Style.ShortNamespaceLines = 0;
+  Style.MaxEmptyLinesToKeep = 2;
+  Style.WrapNamespaceBodyWithEmptyLines = FormatStyle::WNBWELS_Never;
+  Style.CompactNamespaces = false;
+
+  // Empty namespace
+  verifyNoChange("namespace N {};", Style);
+
+  // Single namespace
+  verifyNoChange("namespace N {\n"
+                 "int f1(int a) { return 2 * a; }\n"
+                 "};",
+                 Style);
+
+  // Nested namespace
+  verifyNoChange("namespace N1 {\n"
+                 "namespace N2 {\n"
+                 "namespace N3 {\n"
+                 "int f1() {\n"
+                 "  int a = 1;\n"
+                 "  return a;\n"
+                 "}\n"
+                 "}\n"
+                 "}\n"
+                 "}",
+                 Style);
+
+  Style.CompactNamespaces = true;
+
+  // Empty namespace
+  verifyNoChange("namespace N1 { namespace N2 {\n"
+                 "}};",
+                 Style);
+
+  // Single namespace
+  verifyNoChange("namespace N {\n"
+                 "int f1(int a) { return 2 * a; }\n"
+                 "};",
+                 Style);
+
+  // Nested namespace
+  verifyNoChange("namespace N1 { namespace N2 { namespace N3 {\n"
+                 "int f1() {\n"
+                 "  int a = 1;\n"
+                 "  return a;\n"
+                 "}\n"
+                 "}}}",
+                 Style);
+}
+
+TEST_F(FormatTest, WrapNamespaceBodyWithEmptyLinesAlways) {
+  FormatStyle Style = getLLVMStyle();
+  Style.FixNamespaceComments = false;
+  Style.ShortNamespaceLines = 0;
+  Style.MaxEmptyLinesToKeep = 0;
+  Style.WrapNamespaceBodyWithEmptyLines = FormatStyle::WNBWELS_Always;
+  Style.CompactNamespaces = false;
+
+  // Empty namespace
+  verifyNoChange("namespace N {};", Style);
+
+  // Single namespace
+  verifyNoChange("namespace N {\n"
+                 "\n"
+                 "int f1(int a) { return 2 * a; }\n"
+                 "\n"
+                 "};",
+                 Style);
+
+  // Nested namespace
+  verifyNoChange("namespace N1 {\n"
+                 "namespace N2 {\n"
+                 "namespace N3 {\n"
+                 "\n"
+                 "int f1() {\n"
+                 "  int a = 1;\n"
+                 "  return a;\n"
+                 "}\n"
+                 "\n"
+                 "}\n"
+                 "}\n"
+                 "}",
+                 Style);
+
+  Style.CompactNamespaces = true;
+
+  // Nested namespace
+  verifyNoChange("namespace N1 { namespace N2 { namespace N3 {\n"
+                 "\n"
+                 "int f1() {\n"
+                 "  int a = 1;\n"
+                 "  return a;\n"
+                 "}\n"
+                 "\n"
+                 "}}}",
+                 Style);
+
+  Style.MaxEmptyLinesToKeep = 2;
+  Style.CompactNamespaces = false;
+
+  // Empty namespace
+  verifyNoChange("namespace N {};", Style);
+
+  // Single namespace
+  verifyNoChange("namespace N {\n"
+                 "\n"
+                 "\n"
+                 "void function()\n"
+                 "\n"
+                 "\n"
+                 "};",
+                 Style);
+
+  // Nested namespace
+  verifyFormat("namespace N1 {\n"
+               "namespace N2 {\n"
+               "namespace N3 {\n"
+               "\n"
+               "\n"
+               "int f1() {\n"
+               "  int a = 1;\n"
+               "  return a;\n"
+               "}\n"
+               "\n"
+               "\n"
+               "}\n"
+               "}\n"
+               "}",
+               "namespace N1 {\n"
+               "namespace N2 {\n"
+               "\n"
+               "namespace N3 {\n"
+               "\n"
+               "\n"
+               "int f1() {\n"
+               "  int a = 1;\n"
+               "  return a;\n"
+               "}\n"
+               "\n"
+               "\n"
+               "}\n"
+               "\n"
+               "}\n"
+               "}",
+               Style);
+
+  Style.CompactNamespaces = true;
+
+  // Nested namespace
+  verifyNoChange("namespace N1 { namespace N2 { namespace N3 {\n"
+                 "\n"
+                 "\n"
+                 "int f1() {\n"
+                 "  int a = 1;\n"
+                 "  return a;\n"
+                 "}\n"
+                 "\n"
+                 "\n"
+                 "}}}",
+                 Style);
+}
+
+TEST_F(FormatTest, WrapNamespaceBodyWithEmptyLinesLeave) {
+  FormatStyle Style = getLLVMStyle();
----------------
owenca wrote:

```suggestion
  auto Style = getLLVMStyle();
```

https://github.com/llvm/llvm-project/pull/106145