Provide better error messages about version mismatches

get_releasenote.py

@@ -85,6 +85,7 @@ def parse_changes(
 
     return _parse_changes(
         changes=changes,
+        changes_file=changes_file,
         version=ctx.version,
         start_line=start_line,
         head_line=head_line,
@@ -96,6 +97,7 @@ def parse_changes(
 def _parse_changes(
     *,
     changes: str,
+    changes_file: str,
     version: str,
     start_line: str,
     head_line: str,
@@ -105,7 +107,10 @@ def _parse_changes(
 ) -> str:
     top, sep, msg = changes.partition(start_line)
     if not sep:
-        raise ValueError(f"Cannot find TOWNCRIER start mark ({start_line!r})")
+        raise ValueError(
+            f"Cannot find TOWNCRIER start mark ({start_line!r}) "
+            "in file '{changes_file}'"
+        )
 
     msg = msg.strip()
     head_re = re.compile(
@@ -119,11 +124,11 @@ def _parse_changes(
     match = head_re.match(msg)
     if match is None:
         raise ValueError(
-            f"Cannot find TOWNCRIER version head mark ({head_re.pattern!r})"
+            f"Cannot find TOWNCRIER version head mark ({head_re.pattern!r}) "
+            f"in file '{changes_file}'"
         )
     found_version = match.group("version")
-    if version != found_version:
-        raise ValueError(f"Version check mismatch: {version} != {found_version}")
+    check_changes_version(version, found_version, changes_file)
 
     match2 = head_re.search(msg, match.end())
     if match2 is not None:
@@ -138,6 +143,29 @@ def _parse_changes(
     return msg.strip()
 
 
+def check_changes_version(
+    declared_version: str, found_version: str, changes_file: str
+) -> None:
+    if declared_version == found_version:
+        return
+    dver = parse_version(declared_version)
+    fver = parse_version(found_version)
+
+    if dver < fver:
+        raise ValueError(
+            f"The distribution version {dver} is older than "
+            f"{fver} (from '{changes_file}').\n"
+            "Hint: push git tag with the latest version."
+        )
+
+    else:
+        raise ValueError(
+            f"The distribution version {dver} is younger than "
+            f"{fver} (from '{changes_file}').\n"
+            "Hint: run 'towncrier' again."
+        )
+
+
 VERSION_RE = re.compile(
     "^{version} *= *{spec}".format(
         version="(?:__version__|version)",

tests/test_parse_changes.py

@@ -0,0 +1,247 @@
+from textwrap import dedent
+
+import pytest
+
+from get_releasenote import _parse_changes
+
+START_LINE = ".. towncrier release notes start"
+
+
+def test_parse_no_start_line() -> None:
+    with pytest.raises(ValueError, match="Cannot find TOWNCRIER start mark"):
+        _parse_changes(
+            changes="text",
+            changes_file="CHANGES.rst",
+            version="1.2.3",
+            start_line=START_LINE,
+            head_line="{version} \\({date}\\)\n=====+\n?",
+            fix_issue_regex="",
+            fix_issue_repl="",
+            name="name",
+        )
+
+
+def test_parse_no_head_line() -> None:
+    CHANGES = dedent(
+        f"""\
+      {START_LINE}
+      NO-VERSION
+    """
+    )
+    with pytest.raises(ValueError, match="Cannot find TOWNCRIER version head mark"):
+        _parse_changes(
+            changes=CHANGES,
+            changes_file="CHANGES.rst",
+            version="1.2.3",
+            start_line=START_LINE,
+            head_line="{version} \\({date}\\)\n=====+\n?",
+            fix_issue_regex="",
+            fix_issue_repl="",
+            name="name",
+        )
+
+
+def test_parse_version_older() -> None:
+    CHANGES = dedent(
+        f"""\
+      {START_LINE}
+
+      1.2.4 (2020-12-16)
+      ==================
+
+    """
+    )
+    with pytest.raises(
+        ValueError, match="The distribution version 1.2.3 is older than 1.2.4"
+    ):
+        _parse_changes(
+            changes=CHANGES,
+            changes_file="CHANGES.rst",
+            version="1.2.3",
+            start_line=START_LINE,
+            head_line="{version} \\({date}\\)\n=====+\n?",
+            fix_issue_regex="",
+            fix_issue_repl="",
+            name="name",
+        )
+
+
+def test_parse_version_younger() -> None:
+    CHANGES = dedent(
+        f"""\
+      {START_LINE}
+
+      1.2.4 (2020-12-16)
+      ==================
+
+    """
+    )
+    with pytest.raises(
+        ValueError, match="The distribution version 1.2.5 is younger than 1.2.4"
+    ):
+        _parse_changes(
+            changes=CHANGES,
+            changes_file="CHANGES.rst",
+            version="1.2.5",
+            start_line=START_LINE,
+            head_line="{version} \\({date}\\)\n=====+\n?",
+            fix_issue_regex="",
+            fix_issue_repl="",
+            name="name",
+        )
+
+
+def test_parse_single_changes() -> None:
+    CHANGES = dedent(
+        f"""\
+      Header
+      {START_LINE}
+
+      1.2.3 (2020-12-16)
+      ==================
+
+      Features
+      --------
+
+      - Feature 1 (#1024)
+
+      - Feature 2 (#1025)
+
+    """
+    )
+    ret = _parse_changes(
+        changes=CHANGES,
+        changes_file="CHANGES.rst",
+        version="1.2.3",
+        start_line=START_LINE,
+        head_line="{version} \\({date}\\)\n=====+\n?",
+        fix_issue_regex="",
+        fix_issue_repl="",
+        name="name",
+    )
+    assert ret == dedent(
+        """\
+      Features
+      --------
+
+      - Feature 1 (#1024)
+
+      - Feature 2 (#1025)"""
+    )
+
+
+def test_parse_multi_changes() -> None:
+    CHANGES = dedent(
+        f"""\
+      Header
+      {START_LINE}
+
+      1.2.3 (2020-12-16)
+      ==================
+
+      Features
+      --------
+
+      - Feature 1 (#1024)
+
+      - Feature 2 (#1025)
+
+
+
+      1.2.2 (2020-12-15)
+      ==================
+
+      Bugfixes
+      --------
+    """
+    )
+    ret = _parse_changes(
+        changes=CHANGES,
+        changes_file="CHANGES.rst",
+        version="1.2.3",
+        start_line=START_LINE,
+        head_line="{version} \\({date}\\)\n=====+\n?",
+        fix_issue_regex="",
+        fix_issue_repl="",
+        name="name",
+    )
+    assert ret == dedent(
+        """\
+      Features
+      --------
+
+      - Feature 1 (#1024)
+
+      - Feature 2 (#1025)"""
+    )
+
+
+def test_parse_fix_issues() -> None:
+    CHANGES = dedent(
+        f"""\
+      Header
+      {START_LINE}
+
+      1.2.3 (2020-12-16)
+      ==================
+
+      Features
+      --------
+
+      - Feature 1 `#4603 <https://github.com/aio-libs/aiohttp/issues/4603>`_
+    """
+    )
+    ret = _parse_changes(
+        changes=CHANGES,
+        changes_file="CHANGES.rst",
+        version="1.2.3",
+        start_line=START_LINE,
+        head_line="{version} \\({date}\\)\n=====+\n?",
+        fix_issue_regex=(
+            "\n?\\s*`#(\\d+) <https://github.com/aio-libs/aiohttp/issues/\\1>`_"
+        ),
+        fix_issue_repl=" (#\\1)",
+        name="name",
+    )
+    assert ret == dedent(
+        """\
+      Features
+      --------
+
+      - Feature 1 (#4603)"""
+    )
+
+
+def test_parse_with_name() -> None:
+    CHANGES = dedent(
+        f"""\
+      Header
+      {START_LINE}
+
+      Project 1.2.3 (2020-12-16)
+      ==========================
+
+      Features
+      --------
+
+      - Feature 1 (#1024)
+
+    """
+    )
+    ret = _parse_changes(
+        changes=CHANGES,
+        changes_file="CHANGES.rst",
+        version="1.2.3",
+        start_line=START_LINE,
+        head_line="Project {version} \\({date}\\)\n=====+\n?",
+        fix_issue_regex="",
+        fix_issue_repl="",
+        name="name",
+    )
+    assert ret == dedent(
+        """\
+      Features
+      --------
+
+      - Feature 1 (#1024)"""
+    )