Implemented matches()

src/myfasthtml/core/matcher.py

@@ -3,6 +3,8 @@ from dataclasses import dataclass
 
 from fastcore.basics import NotStr
 
+from myfasthtml.core.testclient import MyFT
+
 
 class Predicate:
   def __init__(self, value):
@@ -13,6 +15,14 @@ class Predicate:
   
   def __str__(self):
     return f"{self.__class__.__name__}({self.value})"
+  
+  def __eq__(self, other):
+    if not isinstance(other, Predicate):
+      return False
+    return self.value == other.value
+  
+  def __hash__(self):
+    return hash(self.value)
 
 
 class StartsWith(Predicate):
@@ -73,51 +83,152 @@ class ErrorOutput:
     # first render the path hierarchy
     for p in self.path.split(".")[:-1]:
       elt_name, attr_name, attr_value = self._unconstruct_path_item(p)
-      path_str = f'({elt_name} "{attr_name}"="{attr_value}"' if attr_name else f"({elt_name}"
+      path_str = self._str_element(MyFT(elt_name, {attr_name: attr_value}), keep_open=True)
-      self._add_to_output(f"{path_str} ...")
+      self._add_to_output(f"{path_str}")
       self.indent += "  "
     
     # then render the element
     if hasattr(self.expected, "tag") and hasattr(self.element, "tag"):
-      # render the attributes
+      # display the tag and its attributes
-      elt_attrs = {attr_name: self.element.attrs.get(attr_name, "** MISSING **") for attr_name in self.expected.attrs}
+      tag_str = self._str_element(self.element, self.expected)
-      elt_attrs_str = " ".join(f'"{attr_name}"="{attr_value}"' for attr_name, attr_value in elt_attrs.items())
-      tag_str = f"({self.element.tag} {elt_attrs_str}"
-      if len(self.expected.children) == 0:  tag_str += ")"
       self._add_to_output(tag_str)
       
-      # display the error in the attributes
+      # Try to show where the differences are
-      attrs_in_error = [attr_name for attr_name, attr_value in elt_attrs.items() if
+      error_str = self._detect_error(self.element, self.expected)
-                        attr_value != self.expected.attrs[attr_name]]
+      if error_str:
-      if attrs_in_error:
-        elt_attrs_error = " ".join(len(f'"{name}"="{value}"') * ("^" if name in attrs_in_error else " ")
-                                   for name, value in elt_attrs.items())
-        error_str = f" {len(self.element.tag) * " "} {elt_attrs_error}"
         self._add_to_output(error_str)
       
       # render the children
       if len(self.expected.children) > 0:
         self.indent += "  "
         element_index = 0
-        for child in self.expected.children:
+        for expected_child in self.expected.children:
-          if hasattr(child, "tag"):
+          if hasattr(expected_child, "tag"):
-            child_attr_str = " ".join(f'"{attr_name}"="{attr_value}"' for attr_name, attr_value in child.attrs.items())
+            if element_index < len(self.element.children):
-            sub_children_indicator = " ..." if len(child.children) > 0 else ""
+              # display the child
-            child_str = f"({child.tag} {child_attr_str}{sub_children_indicator})"
+              element_child = self.element.children[element_index]
-            self._add_to_output(child_str)
+              child_str = self._str_element(element_child, expected_child, keep_open=False)
+              self._add_to_output(child_str)
+              
+              # manage errors in children
+              child_error_str = self._detect_error(element_child, expected_child)
+              if child_error_str:
+                self._add_to_output(child_error_str)
+              element_index += 1
+            
+            else:
+              # When there are fewer children than expected, we display a placeholder
+              child_str = "! ** MISSING ** !"
+              self._add_to_output(child_str)
+          
           else:
-            self._add_to_output(child)
+            self._add_to_output(expected_child)
         
         self.indent = self.indent[:-2]
         self._add_to_output(")")
+    else:
+      self._add_to_output(str(self.element))
+      # Try to show where the differences are
+      error_str = self._detect_error(self.element, self.expected)
+      if error_str:
+        self._add_to_output(error_str)
   
   def _add_to_output(self, msg):
     self.output.append(f"{self.indent}{msg}")
+  
+  @staticmethod
+  def _str_element(element, expected=None, keep_open=None):
+    # compare to itself if no expected element is provided
+    if expected is None:
+      expected = element
+    
+    # the attributes are compared to the expected element
+    elt_attrs = {attr_name: element.attrs.get(attr_name, "** MISSING **") for attr_name in
+                 [attr_name for attr_name in expected.attrs if attr_name is not None]}
+    elt_attrs_str = " ".join(f'"{attr_name}"="{attr_value}"' for attr_name, attr_value in elt_attrs.items())
+    
+    #
+    tag_str = f"({element.tag} {elt_attrs_str}"
+    
+    # manage the closing tag
+    if keep_open is False:
+      tag_str += " ...)" if len(element.children) > 0 else ")"
+    elif keep_open is True:
+      tag_str += "..." if elt_attrs_str == "" else " ..."
+    else:
+      # close the tag if there are no children
+      if len(element.children) == 0:  tag_str += ")"
+    
+    return tag_str
+  
+  def _detect_error(self, element, expected):
+    if hasattr(expected, "tag") and hasattr(element, "tag"):
+      tag_str = len(element.tag) * (" " if element.tag == expected.tag else "^")
+      elt_attrs = {attr_name: element.attrs.get(attr_name, "** MISSING **") for attr_name in expected.attrs}
+      attrs_in_error = [attr_name for attr_name, attr_value in elt_attrs.items() if
+                        not self._matches(attr_value, expected.attrs[attr_name])]
+      if attrs_in_error:
+        elt_attrs_error = " ".join(len(f'"{name}"="{value}"') * ("^" if name in attrs_in_error else " ")
+                                   for name, value in elt_attrs.items())
+        error_str = f" {tag_str} {elt_attrs_error}"
+        return error_str
+    else:
+      if not self._matches(element, expected):
+        return len(str(element)) * "^"
+    
+    return None
+  
+  @staticmethod
+  def _matches(element, expected):
+    if element == expected:
+      return True
+    elif isinstance(expected, Predicate):
+      return expected.validate(element)
+    else:
+      return element == expected
+
+
+class ErrorComparisonOutput:
+  def __init__(self, actual_error_output, expected_error_output):
+    self.actual_error_output = actual_error_output
+    self.expected_error_output = expected_error_output
+  
+  @staticmethod
+  def adjust(to_adjust, reference):
+    for index, ref_line in enumerate(reference):
+      if "^^" in ref_line:
+        # insert an empty line in to_adjust
+        to_adjust.insert(index, "")
+    
+    return to_adjust
+  
+  def render(self):
+    # init if needed
+    if not self.actual_error_output.output:
+      self.actual_error_output.compute()
+    if not self.expected_error_output.output:
+      self.expected_error_output.compute()
+    
+    actual = self.actual_error_output.output
+    expected = self.expected_error_output.output
+    
+    # actual = self.adjust(actual, expected) # does not seem to be needed
+    expected = self.adjust(expected, actual)
+    
+    actual_max_length = len(max(actual, key=len))
+    # expected_max_length = len(max(expected, key=len))
+    
+    output = []
+    for a, e in zip(actual, expected):
+      line = f"{a:<{actual_max_length}} | {e}".rstrip()
+      output.append(line)
+    
+    return "\n".join(output)
 
 
 def matches(actual, expected, path=""):
   def print_path(p):
-    return f"Path: '{p}'\n\t" if p else ""
+    return f"Path  : '{p}'\n" if p else ""
   
   def _type(x):
     return type(x)
@@ -126,7 +237,11 @@ def matches(actual, expected, path=""):
     return str(elt) if elt else "None"
   
   def _debug_compare(a, b):
-    return f"actual={_debug(a)}, expected={_debug(b)}"
+    actual_out = ErrorOutput(path, a, b)
+    expected_out = ErrorOutput(path, b, b)
+    
+    comparison_out = ErrorComparisonOutput(actual_out, expected_out)
+    return comparison_out.render()
   
   def _error_msg(msg, _actual=None, _expected=None):
     if _actual is None and _expected is None:
@@ -138,7 +253,7 @@ def matches(actual, expected, path=""):
     else:
       debug_info = _debug_compare(_actual, _expected)
     
-    return f"{print_path(path)}{msg} : {debug_info}"
+    return f"{print_path(path)}Error : {msg}\n{debug_info}"
   
   def _assert_error(msg, _actual=None, _expected=None):
     assert False, _error_msg(msg, _actual=_actual, _expected=_expected)
@@ -188,7 +303,7 @@ def matches(actual, expected, path=""):
   
   elif hasattr(expected, "tag"):
     # validate the tags names
-    assert actual.tag == expected.tag, _error_msg("The elements are different: ",
+    assert actual.tag == expected.tag, _error_msg("The elements are different.",
                                                   _actual=actual.tag,
                                                   _expected=expected.tag)
     
@@ -200,14 +315,14 @@ def matches(actual, expected, path=""):
     
     # compare the attributes
     for expected_attr, expected_value in expected.attrs.items():
-      assert expected_attr in actual.attrs, _error_msg(f"'{expected_attr}' is not found in Actual:",
+      assert expected_attr in actual.attrs, _error_msg(f"'{expected_attr}' is not found in Actual.",
                                                        _actual=actual.attrs)
       
       if isinstance(expected_value, Predicate):
         assert expected_value.validate(actual.attrs[expected_attr]), \
-          _error_msg(f"The condition '{expected_value}' is not satisfied: ",
+          _error_msg(f"The condition '{expected_value}' is not satisfied.",
-                     _actual=actual.attrs[expected_attr],
+                     _actual=actual,
-                     _expected=expected_value)
+                     _expected=expected)
       
       else:
         assert actual.attrs[expected_attr] == expected.attrs[expected_attr], \

tests/test_matches.py

@@ -2,7 +2,8 @@ import pytest
 from fastcore.basics import NotStr
 from fasthtml.components import *
 
-from myfasthtml.core.matcher import matches, StartsWith, Contains, DoesNotContain, Empty, DoNotCheck, ErrorOutput
+from myfasthtml.core.matcher import matches, StartsWith, Contains, DoesNotContain, Empty, DoNotCheck, ErrorOutput, \
+  ErrorComparisonOutput
 from myfasthtml.core.testclient import MyFT
 
 
@@ -33,31 +34,31 @@ def test_i_can_match(actual, expected):
 @pytest.mark.parametrize('actual, expected, error_message', [
     (None, Div(), "Actual is None"),
     (Div(), None, "Actual is not None"),
-    (123, Div(), "The types are different:"),
+    (123, Div(), "The types are different"),
-    (123, 124, "The values are different:"),
+    (123, 124, "The values are different"),
-    ([Div(), Span()], [], "Actual is bigger than expected:"),
+    ([Div(), Span()], [], "Actual is bigger than expected"),
-    ([], [Div(), Span()], "Actual is smaller than expected:"),
+    ([], [Div(), Span()], "Actual is smaller than expected"),
-    ("not a list", [Div(), Span()], "The types are different:"),
+    ("not a list", [Div(), Span()], "The types are different"),
-    ([Div(), Span()], [Div(), 123], "The types are different:"),
+    ([Div(), Span()], [Div(), 123], "The types are different"),
-    (Div(), Span(), "The elements are different:"),
+    (Div(), Span(), "The elements are different"),
-    ([Div(), Span()], [Div(), Div()], "The elements are different:"),
+    ([Div(), Span()], [Div(), Div()], "The elements are different"),
-    (Div(), Div(attr1="value"), "'attr1' is not found in Actual:"),
+    (Div(), Div(attr1="value"), "'attr1' is not found in Actual"),
-    (Div(attr2="value"), Div(attr1="value"), "'attr1' is not found in Actual:"),
+    (Div(attr2="value"), Div(attr1="value"), "'attr1' is not found in Actual"),
-    (Div(attr1="value1"), Div(attr1="value2"), "The values are different for 'attr1':"),
+    (Div(attr1="value1"), Div(attr1="value2"), "The values are different for 'attr1'"),
-    (Div(attr1="value1"), Div(attr1=StartsWith("value2")), "The condition 'StartsWith(value2)' is not satisfied:"),
+    (Div(attr1="value1"), Div(attr1=StartsWith("value2")), "The condition 'StartsWith(value2)' is not satisfied"),
-    (Div(attr1="value1"), Div(attr1=Contains("value2")), "The condition 'Contains(value2)' is not satisfied:"),
+    (Div(attr1="value1"), Div(attr1=Contains("value2")), "The condition 'Contains(value2)' is not satisfied"),
     (Div(attr1="value1 value2"), Div(attr1=DoesNotContain("value2")), "The condition 'DoesNotContain(value2)'"),
-    (NotStr("456"), NotStr("123"), "Notstr values are different:"),
+    (NotStr("456"), NotStr("123"), "Notstr values are different"),
-    (Div(attr="value"), Div(Empty()), "Actual is not empty:"),
+    (Div(attr="value"), Div(Empty()), "Actual is not empty"),
-    (Div(120), Div(Empty()), "Actual is not empty:"),
+    (Div(120), Div(Empty()), "Actual is not empty"),
-    (Div(Span()), Div(Empty()), "Actual is not empty:"),
+    (Div(Span()), Div(Empty()), "Actual is not empty"),
-    (Div(), Div(Span()), "Actual is lesser than expected:"),
+    (Div(), Div(Span()), "Actual is lesser than expected"),
-    (Div(), Div(123), "Actual is lesser than expected:"),
+    (Div(), Div(123), "Actual is lesser than expected"),
-    (Div(Span()), Div(Div()), "The elements are different:"),
+    (Div(Span()), Div(Div()), "The elements are different"),
-    (Div(123), Div(Div()), "The types are different:"),
+    (Div(123), Div(Div()), "The types are different"),
-    (Div(123), Div(456), "The values are different:"),
+    (Div(123), Div(456), "The values are different"),
-    (Div(Span(), Span()), Div(Span(), Div()), "The elements are different:"),
+    (Div(Span(), Span()), Div(Span(), Div()), "The elements are different"),
-    (Div(Span(Div())), Div(Span(Span())), "The elements are different:"),
+    (Div(Span(Div())), Div(Span(Span())), "The elements are different"),
 ])
 def test_i_can_detect_errors(actual, expected, error_message):
   with pytest.raises(AssertionError) as exc_info:
@@ -66,14 +67,14 @@ def test_i_can_detect_errors(actual, expected, error_message):
 
 
 @pytest.mark.parametrize('element, expected_path', [
-    (Div(), "Path: 'div"),
+    (Div(), "Path  : 'div"),
-    (Div(Span()), "Path: 'div.span"),
+    (Div(Span()), "Path  : 'div.span"),
-    (Div(Span(Div())), "Path: 'div.span.div"),
+    (Div(Span(Div())), "Path  : 'div.span.div"),
-    (Div(id="div_id"), "Path: 'div#div_id"),
+    (Div(id="div_id"), "Path  : 'div#div_id"),
-    (Div(cls="div_class"), "Path: 'div[class=div_class]"),
+    (Div(cls="div_class"), "Path  : 'div[class=div_class]"),
-    (Div(name="div_class"), "Path: 'div[name=div_class]"),
+    (Div(name="div_class"), "Path  : 'div[name=div_class]"),
-    (Div(attr="value"), "Path: 'div"),
+    (Div(attr="value"), "Path  : 'div"),
-    (Div(Span(Div(), cls="span_class"), id="div_id"), "Path: 'div#div_id.span[class=span_class].div"),
+    (Div(Span(Div(), cls="span_class"), id="div_id"), "Path  : 'div#div_id.span[class=span_class].div"),
 ])
 def test_i_can_properly_show_path(element, expected_path):
   def _construct_test_element(source, tail):
@@ -144,6 +145,44 @@ def test_i_can_output_error_attribute_wrong_value():
                                  '     ^^^^^^^^^^^^^^^^                 ']
 
 
+def test_i_can_output_error_constant():
+  elt = 123
+  expected = elt
+  path = ""
+  error_output = ErrorOutput(path, elt, expected)
+  error_output.compute()
+  assert error_output.output == ['123']
+
+
+def test_i_can_output_error_constant_wrong_value():
+  elt = 123
+  expected = 456
+  path = ""
+  error_output = ErrorOutput(path, elt, expected)
+  error_output.compute()
+  assert error_output.output == ['123',
+                                 '^^^']
+
+
+def test_i_can_output_error_when_predicate():
+  elt = "before value after"
+  expected = Contains("value")
+  path = ""
+  error_output = ErrorOutput(path, elt, expected)
+  error_output.compute()
+  assert error_output.output == ["before value after"]
+
+
+def test_i_can_output_error_when_predicate_wrong_value():
+  elt = "before after"
+  expected = Contains("value")
+  path = ""
+  error_output = ErrorOutput(path, elt, expected)
+  error_output.compute()
+  assert error_output.output == ["before after",
+                                 "^^^^^^^^^^^^"]
+
+
 def test_i_can_output_error_child_element():
   elt = Div(P(id="p_id"), Div(id="child_1"), Div(id="child_2"), attr1="value1")
   expected = elt
@@ -169,3 +208,131 @@ def test_i_can_output_error_child_element_indicating_sub_children():
                                  '  (div "id"="child_1" ...)',
                                  ')',
                                  ]
+
+
+def test_i_can_output_error_child_element_wrong_value():
+  elt = Div(P(id="p_id"), Div(id="child_2"), attr1="value1")
+  expected = Div(P(id="p_id"), Div(id="child_1"), attr1="value1")
+  path = ""
+  error_output = ErrorOutput(path, elt, expected)
+  error_output.compute()
+  assert error_output.output == ['(div "attr1"="value1"',
+                                 '  (p "id"="p_id")',
+                                 '  (div "id"="child_2")',
+                                 '       ^^^^^^^^^^^^^^',
+                                 ')',
+                                 ]
+
+
+def test_i_can_output_error_fewer_elements():
+  elt = Div(P(id="p_id"), attr1="value1")
+  expected = Div(P(id="p_id"), Div(id="child_1"), attr1="value1")
+  path = ""
+  error_output = ErrorOutput(path, elt, expected)
+  error_output.compute()
+  assert error_output.output == ['(div "attr1"="value1"',
+                                 '  (p "id"="p_id")',
+                                 '  ! ** MISSING ** !',
+                                 ')',
+                                 ]
+
+
+def test_i_can_output_comparison():
+  actual = Div(P(id="p_id"), attr1="value1")
+  expected = actual
+  actual_out = ErrorOutput("", actual, expected)
+  expected_out = ErrorOutput("", expected, expected)
+  
+  comparison_out = ErrorComparisonOutput(actual_out, expected_out)
+  
+  res = comparison_out.render()
+  
+  assert "\n" + res == '''
+(div "attr1"="value1" | (div "attr1"="value1"
+  (p "id"="p_id")     |   (p "id"="p_id")
+)                     | )'''
+
+
+def test_i_can_output_comparison_with_path():
+  actual = Div(P(id="p_id"), attr1="value1")
+  expected = actual
+  actual_out = ErrorOutput("div#div_id.span[class=cls].div", actual, expected)
+  expected_out = ErrorOutput("div#div_id.span[class=cls].div", expected, expected)
+  
+  comparison_out = ErrorComparisonOutput(actual_out, expected_out)
+  
+  res = comparison_out.render()
+  
+  assert "\n" + res == '''
+(div "id"="div_id" ...    | (div "id"="div_id" ...
+  (span "class"="cls" ... |   (span "class"="cls" ...
+    (div "attr1"="value1" |     (div "attr1"="value1"
+      (p "id"="p_id")     |       (p "id"="p_id")
+    )                     |     )'''
+
+
+def test_i_can_output_comparison_when_missing_attributes():
+  actual = Div(P(id="p_id"), attr1="value1")
+  expected = Div(P(id="p_id"), attr2="value1")
+  actual_out = ErrorOutput("", actual, expected)
+  expected_out = ErrorOutput("", expected, expected)
+  
+  comparison_out = ErrorComparisonOutput(actual_out, expected_out)
+  
+  res = comparison_out.render()
+  
+  assert "\n" + res == '''
+(div "attr2"="** MISSING **" | (div "attr2"="value1"
+     ^^^^^^^^^^^^^^^^^^^^^^^ |
+  (p "id"="p_id")            |   (p "id"="p_id")
+)                            | )'''
+
+
+def test_i_can_output_comparison_when_wrong_attributes():
+  actual = Div(P(id="p_id"), attr1="value2")
+  expected = Div(P(id="p_id"), attr1="value1")
+  actual_out = ErrorOutput("", actual, expected)
+  expected_out = ErrorOutput("", expected, expected)
+  
+  comparison_out = ErrorComparisonOutput(actual_out, expected_out)
+  
+  res = comparison_out.render()
+  
+  assert "\n" + res == '''
+(div "attr1"="value2" | (div "attr1"="value1"
+     ^^^^^^^^^^^^^^^^ |
+  (p "id"="p_id")     |   (p "id"="p_id")
+)                     | )'''
+
+
+def test_i_can_output_comparison_when_fewer_elements():
+  actual = Div(P(id="p_id"), attr1="value1")
+  expected = Div(Span(id="s_id"), P(id="p_id"), attr1="value1")
+  actual_out = ErrorOutput("", actual, expected)
+  expected_out = ErrorOutput("", expected, expected)
+  
+  comparison_out = ErrorComparisonOutput(actual_out, expected_out)
+  
+  res = comparison_out.render()
+  
+  assert "\n" + res == '''
+(div "attr1"="value1" | (div "attr1"="value1"
+  (p "id"="p_id")     |   (span "id"="s_id")
+   ^ ^^^^^^^^^^^      |
+  ! ** MISSING ** !   |   (p "id"="p_id")
+)                     | )'''
+
+
+def test_i_can_see_the_diff_when_matching():
+  actual = Div(attr1="value1")
+  expected = Div(attr1=Contains("value2"))
+  
+  with pytest.raises(AssertionError) as exc_info:
+    matches(actual, expected)
+  
+  debug_output = str(exc_info.value)
+  assert "\n" + debug_output == """
+Path  : 'div'
+Error : The condition 'Contains(value2)' is not satisfied.
+(div "attr1"="value1") | (div "attr1"="Contains(value2)")
+     ^^^^^^^^^^^^^^^^  |"""