[clang] [clang-format] Add BreakBeforeTemplateClose option (PR #118046)

[Owen Pan via cfe-commits]

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@@ -11224,6 +11224,328 @@ TEST_F(FormatTest, WrapsTemplateDeclarationsWithComments) {
       Style);
 }
 
+TEST_F(FormatTest, BreakBeforeTemplateCloser) {
+  FormatStyle Style = getLLVMStyle();
+  // Begin with tests covering the case where there is no constraint on the
+  // column limit.
+  Style.ColumnLimit = 0;
+  // When BreakBeforeTemplateCloser is turned off, the line break that it adds
+  // shall be removed:
+  verifyFormat("template <\n"
+               "    typename Foo,\n"
+               "    typename Bar>\n"
+               "void foo() {}",
+               "template <\n"
+               "    typename Foo,\n"
+               "    typename Bar\n"
+               ">\n"
+               "void foo() {}",
+               Style);
+
+  Style.BreakBeforeTemplateCloser = true;
+  // BreakBeforeTemplateCloser should NOT force template declarations onto
+  // multiple lines.
+  verifyFormat("template <typename Foo>\n"
+               "void foo() {}",
+               Style);
+  verifyFormat("template <typename Foo, typename Bar>\n"
+               "void foo() {}",
+               Style);
+  // It should allow a line break, even when the typename is short.
+  // verifyNoChange is needed because the default behavior is one line.
+  verifyNoChange("template <\n"
+                 "    typename Foo\n"
+                 ">\n"
+                 "void foo() {}",
+                 Style);
+  verifyNoChange("template <\n"
+                 "    typename Foo,\n"
+                 "    typename Bar\n"
+                 ">\n"
+                 "void foo() {}",
+                 Style);
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owenca wrote:

Delete. Redundant to the test cases at lines 11272 and 11280 below as `verifyFormat(Output, Input)` also checks the stability of `Output`.

https://github.com/llvm/llvm-project/pull/118046