Implement the official gherkin parser

CHANGES.rst

@@ -3,6 +3,10 @@ Changelog
 
 Unreleased
 ----------
+- Use `gherkin-official` parser to replace custom parsing logic.
+- Multiline steps must now always use triple-quotes for the additional lines.
+- All feature files must now use the keyword `Feature:` to be considered valid.
+- Tags can no longer have spaces (e.g. "@tag one" "@tag two" are no longer valid).
 
 7.2.0
 ----------

pyproject.toml

@@ -42,6 +42,7 @@ parse-type = "*"
 pytest = ">=6.2.0"
 typing-extensions = "*"
 packaging = "*"
+gherkin-official = "^29.0.0"
 
 [tool.poetry.group.dev.dependencies]
 tox = ">=4.11.3"

src/pytest_bdd/exceptions.py

@@ -27,11 +27,58 @@ class NoScenariosFound(Exception):
     """No scenarios found."""
 
 
-class FeatureError(Exception):
-    """Feature parse error."""
+class GherkinParseError(Exception):
+    """Base class for all Gherkin parsing errors."""
 
-    message = "{0}.\nLine number: {1}.\nLine: {2}.\nFile: {3}"
+    def __init__(self, message, line, line_content, filename):
+        super().__init__(message)
+        self.message = message
+        self.line = line
+        self.line_content = line_content
+        self.filename = filename
+        self.line = line
+        self.line_content = line_content
+        self.filename = filename
 
-    def __str__(self) -> str:
-        """String representation."""
-        return self.message.format(*self.args)
+    def __str__(self):
+        return f"{self.__class__.__name__}: {self.message}\nLine number: {self.line}\nLine: {self.line_content}\nFile: {self.filename}"
+
+
+class FeatureError(GherkinParseError):
+    pass
+
+
+class BackgroundError(GherkinParseError):
+    pass
+
+
+class ScenarioOutlineError(GherkinParseError):
+    pass
+
+
+class ScenarioError(GherkinParseError):
+    pass
+
+
+class ExamplesError(GherkinParseError):
+    pass
+
+
+class StepError(GherkinParseError):
+    pass
+
+
+class TagError(GherkinParseError):
+    pass
+
+
+class RuleError(GherkinParseError):
+    pass
+
+
+class DocStringError(GherkinParseError):
+    pass
+
+
+class TokenError(GherkinParseError):
+    pass

src/pytest_bdd/feature.py

@@ -29,7 +29,7 @@
 import glob
 import os.path
 
-from .parser import Feature, parse_feature
+from .parser import Feature, FeatureParser
 
 # Global features dictionary
 features: dict[str, Feature] = {}
@@ -52,7 +52,7 @@ def get_feature(base_path: str, filename: str, encoding: str = "utf-8") -> Featu
     full_name = os.path.abspath(os.path.join(base_path, filename))
     feature = features.get(full_name)
     if not feature:
-        feature = parse_feature(base_path, filename, encoding=encoding)
+        feature = FeatureParser(base_path, filename, encoding).parse()
         features[full_name] = feature
     return feature