[RDF] Suppress diagnostics in dataframe_snapshot tests.

tree/dataframe/test/dataframe_snapshot.cxx

@@ -611,7 +611,12 @@ TEST(RDFSnapshotMore, ReadWriteNestedLeaves)
    RDataFrame d(treename, fname);
    const auto outfname = "out_readwritenestedleaves.root";
    ROOT::RDF::RNode d2(d);
-   ROOT_EXPECT_INFO((d2 = *d.Snapshot<int, int>(treename, outfname, {"v.a", "v.b"})), "Snapshot", "Column v.a will be saved as v_a\nInfo in <Snapshot>: Column v.b will be saved as v_b");
+   {
+      ExpectedDiagRAII diagRAII;
+      diagRAII.expectedDiag(ExpectedDiagRAII::EDK_Info, "Snapshot", "Column v.a will be saved as v_a");
+      diagRAII.expectedDiag(ExpectedDiagRAII::EDK_Info, "Snapshot", "Column v.b will be saved as v_b");
+      d2 = *d.Snapshot<int, int>(treename, outfname, {"v.a", "v.b"});
+   }
    EXPECT_EQ(d2.GetColumnNames(), std::vector<std::string>({"v_a", "v_b"}));
    auto check_a_b = [](int a, int b) {
       EXPECT_EQ(a, 1);
@@ -810,6 +815,7 @@ TEST(RDFSnapshotMore, ForbiddenOutputFilename)
    // If some other test case called EnableThreadSafety, the error printed here is of the form
    // "SysError in <TFile::TFile>: file /definitely/not/a/valid/path/f.root can not be opened No such file or directory\nError in <TReentrantRWLock::WriteUnLock>: Write lock already released for 0x55f179989378\n"
    // but the address printed changes every time
+   ExpectedDiagRAII diagRAII{ExpectedDiagRAII::EDK_SysError, "TFile::TFile", "file /definitely/not/a/valid/path/f.root can not be opened No such file or directory"};
    EXPECT_THROW(df.Snapshot("t", out_fname, {"rdfslot_"}), std::runtime_error);
 }
 
@@ -1103,6 +1109,9 @@ TEST(RDFSnapshotMore, ForbiddenOutputFilenameMT)
    // the error printed here is
    // "SysError in <TFile::TFile>: file /definitely/not/a/valid/path/f.root can not be opened No such file or directory\nError in <TReentrantRWLock::WriteUnLock>: Write lock already released for 0x55f179989378\n"
    // but the address printed changes every time
+   ExpectedDiagRAII diagRAII;
+   diagRAII.expectedDiag(ExpectedDiagRAII::EDK_SysError, "TFile::TFile", "file /definitely/not/a/valid/path/f.root can not be opened No such file or directory");
+   diagRAII.optionalDiag(ExpectedDiagRAII::EDK_Error, "TReentrantRWLock::WriteUnLock", "Write lock already released for", /*wholeStringNeedsToMatch=*/false);
    EXPECT_THROW(df.Snapshot("t", out_fname, {"rdfslot_"}), std::runtime_error);
 }