Improve test coverage

docs/Makefile

@@ -7,10 +7,12 @@ SPHINXBUILD   = sphinx-build
 PAPER         =
 BUILDDIR      = _build
 
-# User-friendly check for sphinx-build
-ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-	$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don\'t have Sphinx installed, grab it from http://sphinx-doc.org/)
-endif
+.PHONY: sphinx
+sphinx:
+	# User-friendly check for sphinx-build
+	ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
+		$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don\'t have Sphinx installed, grab it from http://sphinx-doc.org/)
+	endif
 
 # Internal variables.
 PAPEROPT_a4     = -D latex_paper_size=a4
@@ -54,44 +56,44 @@ clean:
 	rm -rf $(BUILDDIR)/*
 
 .PHONY: html
-html:
+html: sphinx
 	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
 
 .PHONY: dirhtml
-dirhtml:
+dirhtml: sphinx
 	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
 
 .PHONY: singlehtml
-singlehtml:
+singlehtml: sphinx
 	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
 	@echo
 	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
 
 .PHONY: pickle
-pickle:
+pickle: sphinx
 	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
 	@echo
 	@echo "Build finished; now you can process the pickle files."
 
 .PHONY: json
-json:
+json: sphinx
 	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
 	@echo
 	@echo "Build finished; now you can process the JSON files."
 
 .PHONY: htmlhelp
-htmlhelp:
+htmlhelp: sphinx
 	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
 	@echo
 	@echo "Build finished; now you can run HTML Help Workshop with the" \
 	      ".hhp project file in $(BUILDDIR)/htmlhelp."
 
 .PHONY: qthelp
-qthelp:
+qthelp: sphinx
 	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
 	@echo
 	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
@@ -101,7 +103,7 @@ qthelp:
 	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/zarr.qhc"
 
 .PHONY: applehelp
-applehelp:
+applehelp: sphinx
 	$(SPHINXBUILD) -b applehelp $(ALLSPHINXOPTS) $(BUILDDIR)/applehelp
 	@echo
 	@echo "Build finished. The help book is in $(BUILDDIR)/applehelp."
@@ -110,7 +112,7 @@ applehelp:
 	      "bundle."
 
 .PHONY: devhelp
-devhelp:
+devhelp: sphinx
 	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
 	@echo
 	@echo "Build finished."
@@ -120,111 +122,112 @@ devhelp:
 	@echo "# devhelp"
 
 .PHONY: epub
-epub:
+epub: sphinx
 	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
 	@echo
 	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
 
 .PHONY: epub3
-epub3:
+epub3: sphinx
 	$(SPHINXBUILD) -b epub3 $(ALLSPHINXOPTS) $(BUILDDIR)/epub3
 	@echo
 	@echo "Build finished. The epub3 file is in $(BUILDDIR)/epub3."
 
 .PHONY: latex
-latex:
+latex: sphinx
 	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
 	@echo
 	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
 	@echo "Run \`make' in that directory to run these through (pdf)latex" \
 	      "(use \`make latexpdf' here to do that automatically)."
 
 .PHONY: latexpdf
-latexpdf:
+latexpdf: sphinx
 	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
 	@echo "Running LaTeX files through pdflatex..."
 	$(MAKE) -C $(BUILDDIR)/latex all-pdf
 	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
 
 .PHONY: latexpdfja
-latexpdfja:
+latexpdfja: sphinx
 	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
 	@echo "Running LaTeX files through platex and dvipdfmx..."
 	$(MAKE) -C $(BUILDDIR)/latex all-pdf-ja
 	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
 
 .PHONY: text
-text:
+text: sphinx
 	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
 	@echo
 	@echo "Build finished. The text files are in $(BUILDDIR)/text."
 
 .PHONY: man
-man:
+man: sphinx
 	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
 	@echo
 	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
 
 .PHONY: texinfo
-texinfo:
+texinfo: sphinx
 	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
 	@echo
 	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
 	@echo "Run \`make' in that directory to run these through makeinfo" \
 	      "(use \`make info' here to do that automatically)."
 
 .PHONY: info
-info:
+info: sphinx
 	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
 	@echo "Running Texinfo files through makeinfo..."
 	make -C $(BUILDDIR)/texinfo info
 	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
 
 .PHONY: gettext
-gettext:
+gettext: sphinx
 	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
 	@echo
 	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
 
 .PHONY: changes
-changes:
+changes: sphinx
 	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
 	@echo
 	@echo "The overview file is in $(BUILDDIR)/changes."
 
 .PHONY: linkcheck
-linkcheck:
+linkcheck: sphinx
 	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
 	@echo
 	@echo "Link check complete; look for any errors in the above output " \
 	      "or in $(BUILDDIR)/linkcheck/output.txt."
 
 .PHONY: doctest
-doctest:
+doctest: sphinx
 	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
 	@echo "Testing of doctests in the sources finished, look at the " \
 	      "results in $(BUILDDIR)/doctest/output.txt."
 
 .PHONY: coverage
-coverage:
+coverage: sphinx
 	$(SPHINXBUILD) -b coverage $(ALLSPHINXOPTS) $(BUILDDIR)/coverage
 	@echo "Testing of coverage in the sources finished, look at the " \
 	      "results in $(BUILDDIR)/coverage/python.txt."
 
 .PHONY: xml
-xml:
+xml: sphinx
 	$(SPHINXBUILD) -b xml $(ALLSPHINXOPTS) $(BUILDDIR)/xml
 	@echo
 	@echo "Build finished. The XML files are in $(BUILDDIR)/xml."
 
 .PHONY: pseudoxml
-pseudoxml:
+pseudoxml: sphinx
 	$(SPHINXBUILD) -b pseudoxml $(ALLSPHINXOPTS) $(BUILDDIR)/pseudoxml
 	@echo
 	@echo "Build finished. The pseudo-XML files are in $(BUILDDIR)/pseudoxml."
 
 .PHONY: dummy
-dummy:
+dummy: sphinx
 	$(SPHINXBUILD) -b dummy $(ALLSPHINXOPTS) $(BUILDDIR)/dummy
 	@echo
 	@echo "Build finished. Dummy builder generates no files."
+

docs/checksum32.rst

@@ -36,8 +36,10 @@ Fletcher32
 JenkinsLookup3
 --------------
 
-.. autoclass:: numcodecs.jenkins.JenkinsLookup3
+.. autoclass:: JenkinsLookup3
 
     .. autoattribute:: codec_id
+    .. autoattribute:: initval
+    .. autoattribute:: prefix
     .. automethod:: encode
     .. automethod:: decode

numcodecs/checksum32.py

@@ -93,7 +93,7 @@ def decode(self, buf, out=None):
                 f" match the expected checksum ({found}).\n"
                 "This could be a sign that the data has been corrupted."
             )
-        if out:
+        if out is not None:
             out.view("uint8")[:] = b[:-4]
             return out
         return memoryview(b[:-4])

numcodecs/fletcher32.pyx

@@ -79,7 +79,7 @@ class Fletcher32(Codec):
                 f" match the expected checksum ({found}).\n"
                 "This could be a sign that the data has been corrupted."
             )
-        if out:
+        if out is not None:
             out.view("uint8")[:] = b[:-4]
             return out
         return memoryview(b[:-4])

numcodecs/tests/test_fletcher32.py

@@ -40,3 +40,10 @@ def test_known():
         1911, -2427, 1897, -2412, 2440, 873, -621, -829, 551, -2118,
     ]
     assert outarr.tolist() == expected
+
+
+def test_out():
+    data = np.frombuffer(bytearray(b"Hello World"), dtype="uint8")
+    f = Fletcher32()
+    result = f.encode(data)
+    f.decode(result, out=data)

numcodecs/tests/test_jenkins.py

@@ -1,4 +1,5 @@
 import numpy as np
+import pytest
 
 from numcodecs.jenkins import jenkins_lookup3
 from numcodecs.checksum32 import JenkinsLookup3
@@ -119,3 +120,30 @@ def test_jenkins_lookup3_codec():
     result = j.encode(chunk_index[:-4])
     j.decode(result)
     assert result == chunk_index
+
+@pytest.mark.parametrize(
+    "dtype",
+    ["uint8", "int32", "float32"]
+)
+def test_with_data(dtype):
+    data = np.arange(100, dtype=dtype)
+    j = JenkinsLookup3()
+    arr = np.frombuffer(j.decode(j.encode(data)), dtype=dtype)
+    assert (arr == data).all()
+
+
+def test_error():
+    data = np.arange(100)
+    j = JenkinsLookup3()
+    enc = j.encode(data)
+    enc2 = bytearray(enc)
+    enc2[0] += 1
+    with pytest.raises(RuntimeError) as e:
+        j.decode(enc2)
+    assert "Bob Jenkin's lookup3 checksum" in str(e.value)
+
+def test_out():
+    data = np.frombuffer(bytearray(b"Hello World"), dtype="uint8")
+    j = JenkinsLookup3()
+    result = j.encode(data)
+    j.decode(result, out=data)