Move blurb file utilities to blurb._blurb_file (#58)

Author: AA-Turner

src/blurb/_add.py

@@ -8,10 +8,11 @@
 import sys
 import tempfile
 
+from blurb._blurb_file import Blurbs
 from blurb._cli import subcommand,error,prompt
 from blurb._git import flush_git_add_files, git_add_files
 from blurb._template import sections, template
-from blurb.blurb import Blurbs, BlurbError
+from blurb.blurb import BlurbError
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:

src/blurb/_blurb_file.py

@@ -0,0 +1,288 @@
+"""
+
+The format of a blurb file:
+
+    ENTRY
+    [ENTRY2
+    ENTRY3
+    ...]
+
+In other words, you may have one or more ENTRYs (entries) in a blurb file.
+
+The format of an ENTRY:
+
+    METADATA
+    BODY
+
+The METADATA section is optional.
+The BODY section is mandatory and must be non-empty.
+
+Format of the METADATA section:
+
+  * Lines starting with ".." are metadata lines of the format:
+        .. name: value
+  * Lines starting with "#" are comments:
+        # comment line
+  * Empty and whitespace-only lines are ignored.
+  * Trailing whitespace is removed.  Leading whitespace is not removed
+    or ignored.
+
+The first nonblank line that doesn't start with ".." or "#" automatically
+terminates the METADATA section and is the first line of the BODY.
+
+Format of the BODY section:
+
+  * The BODY section should be a single paragraph of English text
+    in ReST format.  It should not use the following ReST markup
+    features:
+      * section headers
+      * comments
+      * directives, citations, or footnotes
+      * Any features that require significant line breaks,
+        like lists, definition lists, quoted paragraphs, line blocks,
+        literal code blocks, and tables.
+    Note that this is not (currently) enforced.
+  * Trailing whitespace is stripped.  Leading whitespace is preserved.
+  * Empty lines between non-empty lines are preserved.
+    Trailing empty lines are stripped.
+  * The BODY mustn't start with "Issue #", "gh-", or "- ".
+    (This formatting will be inserted when rendering the final output.)
+  * Lines longer than 76 characters will be wordwrapped.
+      * In the final output, the first line will have
+        "- gh-issue-<gh-issue-number>: " inserted at the front,
+        and subsequent lines will have two spaces inserted
+        at the front.
+
+To terminate an ENTRY, specify a line containing only "..".  End of file
+also terminates the last ENTRY.
+
+-----------------------------------------------------------------------------
+
+The format of a "next" file is exactly the same, except that we're storing
+four pieces of metadata in the filename instead of in the metadata section.
+Those four pieces of metadata are: section, gh-issue, date, and nonce.
+
+-----------------------------------------------------------------------------
+
+In addition to the four conventional metadata (section, gh-issue, date, and nonce),
+there are two additional metadata used per-version: "release date" and
+"no changes".  These may only be present in the metadata block in the *first*
+blurb in a blurb file.
+  * "release date" is the day a particular version of Python was released.
+  * "no changes", if present, notes that there were no actual changes
+    for this version.  When used, there are two more things that must be
+    true about the the blurb file:
+      * There should only be one entry inside the blurb file.
+      * That entry's gh-issue number must be 0.
+
+"""
+
+from __future__ import annotations
+
+import os
+import re
+
+from blurb._template import sanitize_section, sections, unsanitize_section
+from blurb.blurb import BlurbError, textwrap_body, sortable_datetime, nonceify
+
+root = None  # Set by chdir_to_repo_root()
+lowest_possible_gh_issue_number = 32426
+
+
+class Blurbs(list):
+    def parse(self, text: str, *, metadata: dict[str, str] | None = None,
+              filename: str = 'input') -> None:
+        """Parses a string.
+
+        Appends a list of blurb ENTRIES to self, as tuples: (metadata, body)
+        metadata is a dict.  body is a string.
+        """
+
+        metadata = metadata or {}
+        body = []
+        in_metadata = True
+
+        line_number = None
+
+        def throw(s: str):
+            raise BlurbError(f'Error in {filename}:{line_number}:\n{s}')
+
+        def finish_entry() -> None:
+            nonlocal body
+            nonlocal in_metadata
+            nonlocal metadata
+            nonlocal self
+
+            if not body:
+                throw("Blurb 'body' text must not be empty!")
+            text = textwrap_body(body)
+            for naughty_prefix in ('- ', 'Issue #', 'bpo-', 'gh-', 'gh-issue-'):
+                if re.match(naughty_prefix, text, re.I):
+                    throw(f"Blurb 'body' can't start with {naughty_prefix!r}!")
+
+            no_changes = metadata.get('no changes')
+
+            issue_keys = {
+                'gh-issue': 'GitHub',
+                'bpo': 'bpo',
+            }
+            for key, value in metadata.items():
+                # Iterate over metadata items in order.
+                # We parsed the blurb file line by line,
+                # so we'll insert metadata keys in the
+                # order we see them.  So if we issue the
+                # errors in the order we see the keys,
+                # we'll complain about the *first* error
+                # we see in the blurb file, which is a
+                # better user experience.
+                if key in issue_keys:
+                    try:
+                        int(value)
+                    except (TypeError, ValueError):
+                        throw(f'Invalid {issue_keys[key]} number: {value!r}')
+
+                if key == 'gh-issue' and int(value) < lowest_possible_gh_issue_number:
+                    throw(f'Invalid gh-issue number: {value!r} (must be >= {lowest_possible_gh_issue_number})')
+
+                if key == 'section':
+                    if no_changes:
+                        continue
+                    if value not in sections:
+                        throw(f'Invalid section {value!r}!  You must use one of the predefined sections.')
+
+            if 'gh-issue' not in metadata and 'bpo' not in metadata:
+                throw("'gh-issue:' or 'bpo:' must be specified in the metadata!")
+
+            if 'section' not in metadata:
+                throw("No 'section' specified.  You must provide one!")
+
+            self.append((metadata, text))
+            metadata = {}
+            body = []
+            in_metadata = True
+
+        for line_number, line in enumerate(text.split('\n')):
+            line = line.rstrip()
+            if in_metadata:
+                if line.startswith('..'):
+                    line = line[2:].strip()
+                    name, colon, value = line.partition(':')
+                    assert colon
+                    name = name.lower().strip()
+                    value = value.strip()
+                    if name in metadata:
+                        throw(f'Blurb metadata sets {name!r} twice!')
+                    metadata[name] = value
+                    continue
+                if line.startswith('#') or not line:
+                    continue
+                in_metadata = False
+
+            if line == '..':
+                finish_entry()
+                continue
+            body.append(line)
+
+        finish_entry()
+
+    def load(self, filename: str, *, metadata: dict[str, str] | None = None) -> None:
+        """Read a blurb file.
+
+        Broadly equivalent to blurb.parse(open(filename).read()).
+        """
+        with open(filename, encoding='utf-8') as file:
+            text = file.read()
+        self.parse(text, metadata=metadata, filename=filename)
+
+    def __str__(self) -> str:
+        output = []
+        add = output.append
+        add_separator = False
+        for metadata, body in self:
+            if add_separator:
+                add('\n..\n\n')
+            else:
+                add_separator = True
+            if metadata:
+                for name, value in sorted(metadata.items()):
+                    add(f'.. {name}: {value}\n')
+                add('\n')
+            add(textwrap_body(body))
+        return ''.join(output)
+
+    def save(self, path: str) -> None:
+        dirname = os.path.dirname(path)
+        os.makedirs(dirname, exist_ok=True)
+
+        text = str(self)
+        with open(path, 'w', encoding='utf-8') as file:
+            file.write(text)
+
+    @staticmethod
+    def _parse_next_filename(filename: str) -> dict[str, str]:
+        """Returns a dict of blurb metadata from a parsed "next" filename."""
+        components = filename.split(os.sep)
+        section, filename = components[-2:]
+        section = unsanitize_section(section)
+        assert section in sections, f'Unknown section {section}'
+
+        fields = [x.strip() for x in filename.split('.')]
+        assert len(fields) >= 4, f"Can't parse 'next' filename! filename {filename!r} fields {fields}"
+        assert fields[-1] == 'rst'
+
+        metadata = {'date': fields[0], 'nonce': fields[-2], 'section': section}
+
+        for field in fields[1:-2]:
+            for name in ('gh-issue', 'bpo'):
+                _, got, value = field.partition(f'{name}-')
+                if got:
+                    metadata[name] = value.strip()
+                    break
+            else:
+                assert False, f"Found unparsable field in 'next' filename: {field!r}"
+
+        return metadata
+
+    def load_next(self, filename: str) -> None:
+        metadata = self._parse_next_filename(filename)
+        o = type(self)()
+        o.load(filename, metadata=metadata)
+        assert len(o) == 1
+        self.extend(o)
+
+    def ensure_metadata(self) -> None:
+        metadata, body = self[-1]
+        assert 'section' in metadata
+        for name, default in (
+            ('gh-issue', '0'),
+            ('bpo', '0'),
+            ('date', sortable_datetime()),
+            ('nonce', nonceify(body)),
+            ):
+            if name not in metadata:
+                metadata[name] = default
+
+    def _extract_next_filename(self) -> str:
+        """Changes metadata!"""
+        self.ensure_metadata()
+        metadata, body = self[-1]
+        metadata['section'] = sanitize_section(metadata['section'])
+        metadata['root'] = root
+        if int(metadata['gh-issue']) > 0:
+            path = '{root}/Misc/NEWS.d/next/{section}/{date}.gh-issue-{gh-issue}.{nonce}.rst'.format_map(metadata)
+        elif int(metadata['bpo']) > 0:
+            # assume it's a GH issue number
+            path = '{root}/Misc/NEWS.d/next/{section}/{date}.bpo-{bpo}.{nonce}.rst'.format_map(metadata)
+        for name in ('root', 'section', 'date', 'gh-issue', 'bpo', 'nonce'):
+            del metadata[name]
+        return path
+
+    def save_next(self) -> str:
+        assert len(self) == 1
+        blurb = type(self)()
+        metadata, body = self[0]
+        metadata = dict(metadata)
+        blurb.append((metadata, body))
+        filename = blurb._extract_next_filename()
+        blurb.save(filename)
+        return filename

src/blurb/_cli.py

@@ -306,6 +306,6 @@ def test_first_line(filename, test):
 
         break
 
-    import blurb.blurb
-    blurb.blurb.root = path
+    import blurb._blurb_file
+    blurb._blurb_file.root = path
     return path

src/blurb/_merge.py

@@ -2,9 +2,10 @@
 import sys
 from pathlib import Path
 
+from blurb._blurb_file import Blurbs
 from blurb._cli import require_ok, subcommand
 from blurb._versions import glob_versions, printable_version
-from blurb.blurb import Blurbs, glob_blurbs, textwrap_body
+from blurb.blurb import glob_blurbs, textwrap_body
 
 original_dir: str = os.getcwd()
 

src/blurb/_release.py

@@ -4,10 +4,11 @@
 import time
 
 import blurb.blurb
+from blurb._blurb_file import Blurbs
 from blurb._cli import error, subcommand
 from blurb._git import (flush_git_add_files, flush_git_rm_files,
                         git_rm_files, git_add_files)
-from blurb.blurb import Blurbs, glob_blurbs, nonceify
+from blurb.blurb import glob_blurbs, nonceify
 
 
 @subcommand