Merge pull request #115 from paulsengroup/feat/better-errors

Improve error message generated when invalid params are passed to hictkpy.File()

src/file.cpp

@@ -44,9 +44,34 @@ namespace hictkpy::file {
 static void ctor(hictk::File *fp, const std::filesystem::path &path,
                  std::optional<std::int32_t> resolution, std::string_view matrix_type,
                  std::string_view matrix_unit) {
-  new (fp) hictk::File{path.string(), static_cast<std::uint32_t>(resolution.value_or(0)),
-                       hictk::hic::ParseMatrixTypeStr(std::string{matrix_type}),
-                       hictk::hic::ParseUnitStr(std::string{matrix_unit})};
+  const auto resolution_ = static_cast<std::uint32_t>(resolution.value_or(0));
+  try {
+    new (fp) hictk::File{path.string(), resolution_,
+                         hictk::hic::ParseMatrixTypeStr(std::string{matrix_type}),
+                         hictk::hic::ParseUnitStr(std::string{matrix_unit})};
+    // TODO all the exceptions should ideally be handled on the hictk side
+    //      but this will have to do until the next release of hictk
+  } catch (const HighFive::Exception &e) {
+    std::string_view msg{e.what()};
+    if (msg.find("Unable to open the group \"/resolutions/0\"") != std::string_view::npos) {
+      throw std::runtime_error(
+          "resolution is required and cannot be None when opening .mcool files");
+    }
+    throw;
+  } catch (const std::runtime_error &e) {
+    std::string_view msg{e.what()};
+    if (msg.find("resolution cannot be 0 when opening .hic files") != std::string_view::npos) {
+      throw std::runtime_error("resolution is required and cannot be None when opening .hic files");
+    }
+    throw;
+  }
+
+  if (resolution.has_value() && fp->resolution() != resolution_) {
+    // TODO this should also be handled by hictk
+    throw std::runtime_error(
+        fmt::format(FMT_STRING("resolution mismatch for file \"{}\": expected {}, found {}"),
+                    fp->uri(), resolution_, fp->resolution()));
+  }
 }
 
 static std::string repr(const hictk::File &f) {

test/test_file_ctors.py

@@ -0,0 +1,42 @@
+# Copyright (C) 2024 Roberto Rossini <[email protected]>
+#
+# SPDX-License-Identifier: MIT
+
+import pathlib
+
+import pytest
+
+import hictkpy
+
+testdir = pathlib.Path(__file__).resolve().parent
+
+pytestmark = pytest.mark.parametrize(
+    "file,resolution",
+    [
+        (testdir / "data" / "cooler_test_file.mcool", 100_000),
+        (testdir / "data" / "hic_test_file.hic", 100_000),
+    ],
+)
+
+
+class TestClass:
+    def test_resolution_mismatch(self, file, resolution):
+        f = hictkpy.MultiResFile(file)
+
+        if not f[resolution].is_cooler():
+            pytest.skip(f'File "{file}" is not in .mcool format')
+
+        assert 1_000_000 in f.resolutions()
+        with pytest.raises(RuntimeError, match="resolution mismatch"):
+            hictkpy.File(f"{file}::/resolutions/{resolution}", 1_000_000)
+
+    def test_missing_resolution_param(self, file, resolution):
+        f = hictkpy.MultiResFile(file)
+
+        if f[resolution].is_cooler():
+            ext = ".mcool"
+        else:
+            ext = ".hic"
+
+        with pytest.raises(RuntimeError, match=f"resolution is required and cannot be None when opening {ext} files"):
+            hictkpy.File(file)