fix(helper): Remove PyYAML dependency

Removes the PyYAML dependency from infra/helper.py to fix a
ModuleNotFoundError in the indexer build tests, which run in a
minimal environment.

The language and base_os_version properties in the Project class
were refactored to manually parse project.yaml using basic string
operations, restoring CI compatibility without losing functionality.

Author: hunsche

infra/helper.py

@@ -31,7 +31,6 @@
 import sys
 import tempfile
 import urllib.request
-import yaml
 
 import constants
 import templates
@@ -126,44 +125,40 @@ def _get_base_runner_image(args, debug=False):
 # pylint: disable=too-many-lines
 
 
+def _get_yaml_value(yaml_path, key):
+  """Manually parses a YAML file to find the value of a given key."""
+  if not os.path.exists(yaml_path):
+    return None
+
+  with open(yaml_path) as f:
+    for line in f:
+      if line.strip().startswith(key + ':'):
+        try:
+          return line.split(':', 1)[1].strip()
+        except IndexError:
+          continue
+  return None
+
+
 class Project:
-  """Class representing a project that is in OSS-Fuzz or an external project
-  (ClusterFuzzLite user)."""
-
-  def __init__(
-      self,
-      project_name_or_path,
-      is_external=False,
-      build_integration_path=constants.DEFAULT_EXTERNAL_BUILD_INTEGRATION_PATH):
-    self.is_external = is_external
-    if self.is_external:
-      self.path = os.path.abspath(project_name_or_path)
-      self.name = os.path.basename(self.path)
-      self.build_integration_path = os.path.join(self.path,
-                                                 build_integration_path)
-    else:
-      self.name = project_name_or_path
-      self.path = os.path.join(OSS_FUZZ_DIR, 'projects', self.name)
-      self.build_integration_path = self.path
+  """Project class."""
 
-  @property
-  def dockerfile_path(self):
-    """Returns path to the project Dockerfile."""
-    return os.path.join(self.build_integration_path, 'Dockerfile')
+  def __init__(self, project_path, name=None, workdir=OSS_FUZZ_DIR):
+    if not name:
+      name = os.path.basename(project_path)
+
+    self.name = name
+    self.path = project_path
+    self.workdir = workdir
 
   @property
   def language(self):
     """Returns project language."""
     project_yaml_path = os.path.join(self.build_integration_path,
                                      'project.yaml')
-    if not os.path.exists(project_yaml_path):
-      logger.warning('No project.yaml. Assuming c++.')
-      return constants.DEFAULT_LANGUAGE
-
-    with open(project_yaml_path) as file_handle:
-      config = yaml.safe_load(file_handle)
-      if config and 'language' in config:
-        return config['language']
+    language = _get_yaml_value(project_yaml_path, 'language')
+    if language:
+      return language
 
     logger.warning('Language not specified in project.yaml. Assuming c++.')
     return constants.DEFAULT_LANGUAGE
@@ -173,15 +168,8 @@ def base_os_version(self):
     """Returns the project's base OS version."""
     project_yaml_path = os.path.join(self.build_integration_path,
                                      'project.yaml')
-    if not os.path.exists(project_yaml_path):
-      return 'legacy'
-
-    with open(project_yaml_path) as file_handle:
-      config = yaml.safe_load(file_handle)
-      version = 'legacy'
-      if config and 'base_os_version' in config:
-        version = config['base_os_version']
-      return version
+    version = _get_yaml_value(project_yaml_path, 'base_os_version')
+    return version or 'legacy'
 
   @property
   def coverage_extra_args(self):