Improve the message around expecting a semicolon (#833)

This makes it clearer that another character can be used.

Co-authored-by: Pradyun Gedam <[email protected]>

Author: pradyunsg

src/packaging/_parser.py

@@ -111,7 +111,9 @@ def _parse_requirement_details(
             return (url, specifier, marker)
 
         marker = _parse_requirement_marker(
-            tokenizer, span_start=url_start, after="URL and whitespace"
+            tokenizer,
+            span_start=url_start,
+            expected="semicolon (after URL and whitespace)",
         )
     else:
         specifier_start = tokenizer.position
@@ -124,27 +126,28 @@ def _parse_requirement_details(
         marker = _parse_requirement_marker(
             tokenizer,
             span_start=specifier_start,
-            after=(
-                "version specifier"
+            expected=(
+                "comma (within version specifier), semicolon (after version specifier)"
                 if specifier
-                else "name and no valid version specifier"
+                else "semicolon (after name with no version specifier)"
             ),
         )
 
     return (url, specifier, marker)
 
 
 def _parse_requirement_marker(
-    tokenizer: Tokenizer, *, span_start: int, after: str
+    tokenizer: Tokenizer, *, span_start: int, expected: str
 ) -> MarkerList:
     """
     requirement_marker = SEMICOLON marker WS?
     """
 
     if not tokenizer.check("SEMICOLON"):
         tokenizer.raise_syntax_error(
-            f"Expected end or semicolon (after {after})",
+            f"Expected {expected} or end",
             span_start=span_start,
+            span_end=None,
         )
     tokenizer.read()
 

tests/test_requirements.py

@@ -373,7 +373,7 @@ def test_error_no_space_after_url(self) -> None:
         # THEN
         assert ctx.exconly() == (
             "packaging.requirements.InvalidRequirement: "
-            "Expected end or semicolon (after URL and whitespace)\n"
+            "Expected semicolon (after URL and whitespace) or end\n"
             "    name @ https://example.com/; extra == 'example'\n"
             "           ~~~~~~~~~~~~~~~~~~~~~~^"
         )
@@ -521,7 +521,8 @@ def test_error_on_legacy_version_outside_triple_equals(self) -> None:
         # THEN
         assert ctx.exconly() == (
             "packaging.requirements.InvalidRequirement: "
-            "Expected end or semicolon (after version specifier)\n"
+            "Expected comma (within version specifier), "
+            "semicolon (after version specifier) or end\n"
             "    name==1.0.org1\n"
             "        ~~~~~^"
         )
@@ -537,7 +538,7 @@ def test_error_on_missing_version_after_op(self) -> None:
         # THEN
         assert ctx.exconly() == (
             "packaging.requirements.InvalidRequirement: "
-            "Expected end or semicolon (after name and no valid version specifier)\n"
+            "Expected semicolon (after name with no version specifier) or end\n"
             "    name==\n"
             "        ^"
         )
@@ -553,7 +554,7 @@ def test_error_on_missing_op_after_name(self) -> None:
         # THEN
         assert ctx.exconly() == (
             "packaging.requirements.InvalidRequirement: "
-            "Expected end or semicolon (after name and no valid version specifier)\n"
+            "Expected semicolon (after name with no version specifier) or end\n"
             "    name 1.0\n"
             "         ^"
         )
@@ -569,11 +570,29 @@ def test_error_on_random_char_after_specifier(self) -> None:
         # THEN
         assert ctx.exconly() == (
             "packaging.requirements.InvalidRequirement: "
-            "Expected end or semicolon (after version specifier)\n"
+            "Expected comma (within version specifier), "
+            "semicolon (after version specifier) or end\n"
             "    name >= 1.0 #\n"
             "         ~~~~~~~^"
         )
 
+    def test_error_on_missing_comma_in_specifier(self) -> None:
+        # GIVEN
+        to_parse = "name >= 1.0 <= 2.0"
+
+        # WHEN
+        with pytest.raises(InvalidRequirement) as ctx:
+            Requirement(to_parse)
+
+        # THEN
+        assert ctx.exconly() == (
+            "packaging.requirements.InvalidRequirement: "
+            "Expected comma (within version specifier), "
+            "semicolon (after version specifier) or end\n"
+            "    name >= 1.0 <= 2.0\n"
+            "         ~~~~~~~^"
+        )
+
 
 class TestRequirementBehaviour:
     def test_types_with_nothing(self) -> None: