ctest: add option for output truncation

Add `--test-output-truncation` to `ctest`. This option can be used to
customize which part of the test output is being truncated. Currently
supported values are `tail`, `middle` and `head`.

Also add equivalent `CTEST_CUSTOM_TEST_OUTPUT_TRUNCATION` variable.

Fixes: #23206

1 files changed, 12 insertions, 0 deletions

diff --git a/Source/cmCTest.cxx b/Source/cmCTest.cxx
index a1e920e..710b4d7 100644
--- a/Source/cmCTest.cxx
+++ b/Source/cmCTest.cxx
@@ -2036,6 +2036,13 @@ bool cmCTest::HandleCommandLineArguments(size_t& i,
                  "Invalid value for '--test-output-size-failed': " << args[i]
                                                                    << "\n");
     }
+  } else if (this->CheckArgument(arg, "--test-output-truncation"_s) &&
+             i < args.size() - 1) {
+    i++;
+    if (!this->Impl->TestHandler.SetTestOutputTruncation(args[i])) {
+      errormsg = "Invalid value for '--test-output-truncation': " + args[i];
+      return false;
+    }
   } else if (this->CheckArgument(arg, "-N"_s, "--show-only")) {
     this->Impl->ShowOnly = true;
   } else if (cmHasLiteralPrefix(arg, "--show-only=")) {
@@ -2464,6 +2471,11 @@ bool cmCTest::SetArgsFromPreset(const std::string& presetName,
         *expandedPreset->Output->MaxFailedTestOutputSize);
     }
 
+    if (expandedPreset->Output->TestOutputTruncation) {
+      this->Impl->TestHandler.TestOutputTruncation =
+        *expandedPreset->Output->TestOutputTruncation;
+    }
+
     if (expandedPreset->Output->MaxTestNameWidth) {
       this->Impl->MaxTestNameWidth = *expandedPreset->Output->MaxTestNameWidth;
     }