Provide helpful error messages on doctest failures.

IPython/sphinxext/custom_doctests.py

@@ -81,10 +81,26 b' def float_doctest(sphinx_shell, args, input_lines, found, submitted):'
                                  submitted[~submitted_isnan],
                                  rtol=rtol, atol=atol)
 
+    TAB = ' ' * 4
+    directive = sphinx_shell.directive
+    if directive is None:
+        source = 'Unavailable'
+        content = 'Unavailable'
+    else:
+        source = directive.state.document.current_source
+        # Add tabs and make into a single string.
+        content = '\n'.join([TAB + line for line in directive.content])
+
     if error:
-        e = ('doctest float comparison failure for input_lines={0} with '
-             'found_output={1} and submitted '
-             'output="{2}"'.format(input_lines, repr(found), repr(submitted)) )
+
+        e = ('doctest float comparison failure\n\n'
+             'Document source: {0}\n\n'
+             'Raw content: \n{1}\n\n'
+             'On input line(s):\n{TAB}{2}\n\n'
+             'we found output:\n{TAB}{3}\n\n'
+             'instead of the expected:\n{TAB}{4}\n\n')
+        e = e.format(source, content, '\n'.join(input_lines), repr(found),
+                     repr(submitted), TAB=TAB)
         raise RuntimeError(e)
 
 doctests = {

IPython/sphinxext/ipython_directive.py

@@ -155,7 +155,6 b' def block_parser(part, rgxin, rgxout, fmtin, fmtout):'
          INPUT_LINE: the input as string (possibly multi-line)
          REST : any stdout generated by the input line (not OUTPUT)
 
-
       OUTPUT: the output string, possibly multi-line
 
     """
@@ -279,6 +278,9 b' class EmbeddedSphinxShell(object):'
         self.is_doctest = False
         self.is_suppress = False
 
+        # Optionally, provide more detailed information to shell.
+        self.directive = None
+
         # on the first call to the savefig decorator, we'll import
         # pyplot as plt so we can make a call to the plt.gcf().savefig
         self._pyplot_imported = False
@@ -293,7 +295,7 b' class EmbeddedSphinxShell(object):'
 
     def process_input_line(self, line, store_history=True):
         """process the input, capturing stdout"""
-        #print "input='%s'"%self.input
+
         stdout = sys.stdout
         splitter = self.IP.input_splitter
         try:
@@ -337,11 +339,14 b' class EmbeddedSphinxShell(object):'
 
     # Callbacks for each type of token
     def process_input(self, data, input_prompt, lineno):
-        """Process data block for INPUT token."""
+        """
+        Process data block for INPUT token.
+
+        """
         decorator, input, rest = data
         image_file = None
         image_directive = None
-        #print 'INPUT:', data  # dbg
+
         is_verbatim = decorator=='@verbatim' or self.is_verbatim
         is_doctest = (decorator is not None and \
                      decorator.startswith('@doctest')) or self.is_doctest
@@ -403,22 +408,41 b' class EmbeddedSphinxShell(object):'
         self.cout.truncate(0)
         return (ret, input_lines, output, is_doctest, decorator, image_file,
                     image_directive)
-        #print 'OUTPUT', output  # dbg
+
 
     def process_output(self, data, output_prompt,
                        input_lines, output, is_doctest, decorator, image_file):
-        """Process data block for OUTPUT token."""
+        """
+        Process data block for OUTPUT token.
+
+        """
+        TAB = ' ' * 4
+
         if is_doctest and output is not None:
 
             found = output
             found = found.strip()
             submitted = data.strip()
 
+            if self.directive is None:
+                source = 'Unavailable'
+                content = 'Unavailable'
+            else:
+                source = self.directive.state.document.current_source
+                content = self.directive.content
+                # Add tabs and join into a single string.
+                content = '\n'.join([TAB + line for line in content])
+
             # Make sure the output contains the output prompt.
             ind = found.find(output_prompt)
             if ind < 0:
-                e = ('output prompt="{0}" does '
-                     'not match out line={1}'.format(output_prompt, found))
+                e = ('output does not contain output prompt\n\n'
+                     'Document source: {0}\n\n'
+                     'Raw content: \n{1}\n\n'
+                     'Input line(s):\n{TAB}{2}\n\n'
+                     'Output line(s):\n{TAB}{3}\n\n')
+                e = e.format(source, content, '\n'.join(input_lines),
+                             repr(found), TAB=TAB)
                 raise RuntimeError(e)
             found = found[len(output_prompt):].strip()
 
@@ -426,9 +450,14 b' class EmbeddedSphinxShell(object):'
             if decorator.strip() == '@doctest':
                 # Standard doctest
                 if found != submitted:
-                    e = ('doctest failure for input_lines="{0}" with '
-                         'found_output="{1}" and submitted '
-                         'output="{2}"'.format(input_lines, found, submitted) )
+                    e = ('doctest failure\n\n'
+                         'Document source: {0}\n\n'
+                         'Raw content: \n{1}\n\n'
+                         'On input line(s):\n{TAB}{2}\n\n'
+                         'we found output:\n{TAB}{3}\n\n'
+                         'instead of the expected:\n{TAB}{4}\n\n')
+                    e = e.format(source, content, '\n'.join(input_lines),
+                                 repr(found), repr(submitted), TAB=TAB)
                     raise RuntimeError(e)
             else:
                 self.custom_doctest(decorator, input_lines, found, submitted)
@@ -653,6 +682,9 b' class IPythonDirective(Directive):'
             # setting its backend since exec_lines might import pylab.
             self.shell = EmbeddedSphinxShell(exec_lines)
 
+            # Store IPython directive to enable better error messages
+            self.shell.directive = self
+
         # reset the execution count if we haven't processed this doc
         #NOTE: this may be borked if there are multiple seen_doc tmp files
         #check time stamp?
@@ -676,7 +708,6 b' class IPythonDirective(Directive):'
 
         return rgxin, rgxout, promptin, promptout
 
-
     def teardown(self):
         # delete last bookmark
         self.shell.process_input_line('bookmark -d ipy_savedir',
@@ -702,7 +733,7 b' class IPythonDirective(Directive):'
 
         parts = '\n'.join(self.content).split('\n\n')
 
-        lines = ['.. code-block:: ipython','']
+        lines = ['.. code-block:: ipython', '']
         figures = []
 
         for part in parts:
@@ -724,7 +755,9 b' class IPythonDirective(Directive):'
             if debug:
                 print('\n'.join(lines))
             else:
-                # This is what makes the lines appear in the final output.
+                # This has to do with input, not output. But if we comment
+                # these lines out, then no IPython code will appear in the
+                # final output.
                 self.state_machine.insert_input(
                     lines, self.state_machine.input_lines.source(0))