[hist] Check arguments in axis constructors

Author: hahnjo

hist/histv7/inc/ROOT/RRegularAxis.hxx

@@ -44,14 +44,19 @@ class RRegularAxis final {
 public:
    /// Construct a regular axis object.
    ///
-   /// \param[in] numNormalBins the number of normal bins
+   /// \param[in] numNormalBins the number of normal bins, must be > 0
    /// \param[in] low the lower end of the axis interval (inclusive)
-   /// \param[in] high the upper end of the axis interval (exclusive)
+   /// \param[in] high the upper end of the axis interval (exclusive), must be > low
    /// \param[in] enableFlowBins whether to enable underflow and overflow bins
    RRegularAxis(std::size_t numNormalBins, double low, double high, bool enableFlowBins = true)
       : fNumNormalBins(numNormalBins), fLow(low), fHigh(high), fEnableFlowBins(enableFlowBins)
    {
-      // FIXME: should validate numNormalBins > 0 and low < high
+      if (numNormalBins == 0) {
+         throw std::invalid_argument("numNormalBins must be > 0");
+      }
+      if (low >= high) {
+         throw std::invalid_argument("high must be > low");
+      }
       fInvBinWidth = numNormalBins / (high - low);
    }
 

hist/histv7/inc/ROOT/RVariableBinAxis.hxx

@@ -46,7 +46,14 @@ public:
    RVariableBinAxis(std::vector<double> binEdges, bool enableFlowBins = true)
       : fBinEdges(std::move(binEdges)), fEnableFlowBins(enableFlowBins)
    {
-      // FIXME: should validate that fBinEdges is sorted
+      if (fBinEdges.size() < 2) {
+         throw std::invalid_argument("must have >= 2 edges");
+      }
+      for (std::size_t i = 1; i < fBinEdges.size(); i++) {
+         if (fBinEdges[i - 1] >= fBinEdges[i]) {
+            throw std::invalid_argument("binEdges must be sorted");
+         }
+      }
    }
 
    std::size_t GetNumNormalBins() const { return fBinEdges.size() - 1; }

hist/histv7/test/hist_regular.cxx

@@ -16,6 +16,9 @@ TEST(RRegularAxis, Constructor)
    EXPECT_EQ(axis.GetNumNormalBins(), Bins);
    EXPECT_EQ(axis.GetTotalNumBins(), Bins);
    EXPECT_FALSE(axis.HasFlowBins());
+
+   EXPECT_THROW(RRegularAxis(0, 0, Bins), std::invalid_argument);
+   EXPECT_THROW(RRegularAxis(Bins, 1, 1), std::invalid_argument);
 }
 
 TEST(RRegularAxis, Equality)

hist/histv7/test/hist_variable.cxx

@@ -21,6 +21,12 @@ TEST(RVariableBinAxis, Constructor)
    EXPECT_EQ(axis.GetNumNormalBins(), Bins);
    EXPECT_EQ(axis.GetTotalNumBins(), Bins);
    EXPECT_FALSE(axis.HasFlowBins());
+
+   EXPECT_THROW(RVariableBinAxis({}), std::invalid_argument);
+   EXPECT_THROW(RVariableBinAxis({0}), std::invalid_argument);
+   EXPECT_THROW(RVariableBinAxis({0, 0}), std::invalid_argument);
+   EXPECT_THROW(RVariableBinAxis({0, 1, 0}), std::invalid_argument);
+   EXPECT_THROW(RVariableBinAxis({0, 1, 1}), std::invalid_argument);
 }
 
 TEST(RVariableBinAxis, Equality)