Use existing requirements parser to build docs.

build-backend/pex_build/setuptools/build.py

@@ -14,8 +14,9 @@
 # We re-export all setuptools' PEP-517 build backend hooks here for the build frontend to call.
 from setuptools.build_meta import *  # NOQA
 
-from pex import hashing
+from pex import hashing, requirements
 from pex.common import open_zip, temporary_dir
+from pex.orderedset import OrderedSet
 from pex.pep_376 import Hash, InstalledFile, Record
 from pex.version import __version__
 
@@ -26,17 +27,14 @@
 def get_requires_for_build_wheel(config_settings=None):
     # type: (Optional[Dict[str, Any]]) -> List[str]
 
-    reqs = setuptools.build_meta.get_requires_for_build_wheel(
-        config_settings=config_settings
-    )  # type: List[str]
+    reqs = OrderedSet(
+        setuptools.build_meta.get_requires_for_build_wheel(config_settings=config_settings)
+    )  # type: OrderedSet[str]
     if pex_build.INCLUDE_DOCS:
-        with open("docs-requirements.txt") as fp:
-            for raw_req in fp.readlines():
-                req = raw_req.strip()
-                if not req or req.startswith("#"):
-                    continue
-                reqs.append(req)
-    return reqs
+        reqs.update(
+            str(req) for req in requirements.parse_requirement_file("docs-requirements.txt")
+        )
+    return list(reqs)
 
 
 def build_wheel(

pex/requirements.py

@@ -136,19 +136,26 @@ def create_parse_error(msg):
 
 
 @attr.s(frozen=True)
-class PyPIRequirement(object):
+class _ParsedRequirement(object):
+    line = attr.ib()  # type: LogicalLine
+
+    def __str__(self):
+        # type: () -> str
+        return str(self.line.processed_text)
+
+
+@attr.s(frozen=True)
+class PyPIRequirement(_ParsedRequirement):
     """A requirement realized through a package index or find links repository."""
 
-    line = attr.ib()  # type: LogicalLine
     requirement = attr.ib()  # type: Requirement
     editable = attr.ib(default=False)  # type: bool
 
 
 @attr.s(frozen=True)
-class URLRequirement(object):
+class URLRequirement(_ParsedRequirement):
     """A requirement realized through a distribution archive at a fixed URL."""
 
-    line = attr.ib()  # type: LogicalLine
     url = attr.ib()  # type: Text
     requirement = attr.ib()  # type: Requirement
     editable = attr.ib(default=False)  # type: bool
@@ -168,10 +175,9 @@ class Value(Enum.Value):
 
 
 @attr.s(frozen=True)
-class VCSRequirement(object):
+class VCSRequirement(_ParsedRequirement):
     """A requirement realized by building a distribution from sources retrieved from a VCS."""
 
-    line = attr.ib()  # type: LogicalLine
     vcs = attr.ib()  # type: VCS.Value
     url = attr.ib()  # type: Text
     requirement = attr.ib()  # type: Requirement
@@ -219,10 +225,9 @@ def parse_requirement_from_dist(
 
 
 @attr.s(frozen=True)
-class LocalProjectRequirement(object):
+class LocalProjectRequirement(_ParsedRequirement):
     """A requirement realized by building a distribution from local sources."""
 
-    line = attr.ib()  # type: LogicalLine
     path = attr.ib()  # type: str
     extras = attr.ib(default=(), converter=attrs.str_tuple_from_iterable)  # type: Tuple[str, ...]
     marker = attr.ib(default=None)  # type: Optional[Marker]
@@ -241,8 +246,7 @@ def as_requirement(self, dist):
 
 
 @attr.s(frozen=True)
-class Constraint(object):
-    line = attr.ib()  # type: LogicalLine
+class Constraint(_ParsedRequirement):
     requirement = attr.ib()  # type: Requirement