shortener WIP

Author: ramalho

links/shortener.py

@@ -57,24 +57,25 @@
 
 import itertools
 from collections.abc import Iterable, Iterator
-from typing import NamedTuple
+from typing import NamedTuple, TextIO
+from datetime import datetime
 
 
-class ShortenResult(NamedTuple):
-    url: str
+class PathURL(NamedTuple):
     path: str
-    new: bool
+    url: str
+    new: bool = False
 
 
-def parse_htaccess(text: str) -> Iterator[tuple[str, str]]:
+def parse_htaccess(text: str) -> Iterator[PathURL]:
     for line in text.splitlines():
         fields = line.split()
         if len(fields) >= 3 and fields[0] == 'RedirectTemp':
             path = fields[1]
             assert path[0] == '/', f'Missing /: {path!r}'
             path = path[1:]  # Remove leading slash
             assert len(path) > 0, f'Root path in line {line!r}'
-            yield (path, fields[2])
+            yield PathURL(path, fields[2])
 
 
 def choose(a: str, b: str) -> str:
@@ -87,38 +88,43 @@ def key(k: str) -> tuple[int, bool, list[str]]:
     return min(a, b, key=key)
 
 
-def load_redirects(pairs: Iterable[tuple[str, str]]) -> tuple[dict, dict]:
+def load_redirects(pairs: Iterable[PathURL]) -> tuple[dict, dict]:
     redirects = {}
     targets = {}
-    for short_url, url in pairs:
-        url = redirects.setdefault(short_url, url)
-        existing_short_url = targets.get(url)
-        if existing_short_url is None:
-            targets[url] = short_url
+    for path, url, _new in pairs:
+        url = redirects.setdefault(path, url)
+        existing_path = targets.get(url)
+        if existing_path is None:
+            targets[url] = path
         else:
-            targets[url] = choose(short_url, existing_short_url)
+            targets[url] = choose(path, existing_path)
 
     return redirects, targets
 
 
 NO_PATH = ''
 
-def shorten_one(target: str, path_gen: Iterator[str], redirects: dict, targets: dict) -> ShortenResult:
+
+def shorten_one(target: str, path_gen: Iterator[str], redirects: dict, targets: dict) -> PathURL:
     if path := targets.get(target, NO_PATH):
-        return ShortenResult(target, path, False)
+        return PathURL(path, target, False)
     path = next(path_gen)
     redirects[path] = target
     targets[target] = path
-    return ShortenResult(target, path, True)
+    return PathURL(path, target, True)
+
+
+def timestamp():
+    return datetime.now().isoformat(sep=' ', timespec='seconds')
 
 
-def update_htaccess(f: file, srs: list[ShortenResult]) -> int:
+def update_htaccess(f: TextIO, directives: list[PathURL]) -> int:
     """append new redirects, returns count of new redirects"""
-    directives = [t for t in srs if t.new]
+    directives = [d for d in directives if d.new]
     if directives:
-        # xxx write timestamp, then...
-        for url, path, _new in directives:
-            f.write(f'RedirectTemp /{path} {url}')
+        f.write(f'\n# appended {timestamp()}\n')
+        for path, url, _new in directives:
+            f.write(f'RedirectTemp /{path} {url}\n')
     return len(directives)
 
 

links/test_shortener.py

@@ -1,7 +1,12 @@
+import io
+from unittest import mock
+
 from pytest import mark
 
+import shortener  # for mocking timestamp()
 from shortener import parse_htaccess, choose, load_redirects
-from shortener import gen_short, gen_unused_short, shorten_one, ShortenResult
+from shortener import gen_short, gen_unused_short, shorten_one, PathURL
+from shortener import update_htaccess
 
 
 SAMPLE_HTACCESS = """
@@ -23,21 +28,24 @@
 
 FROZEN_TIME = '2025-06-07 01:02:03'
 
-UPDATED_SAMPLE_HTACCESS = SAMPLE_HTACCESS + f"""
-# appended: {FROZEN_TIME}
+UPDATED_SAMPLE_HTACCESS = (
+    SAMPLE_HTACCESS
+    + f"""
+# appended {FROZEN_TIME}
 RedirectTemp /23 https://new.site/
 RedirectTemp /24 https://other.new.site/
 """
+)
 
 
 PARSED_SAMPLE_HTACCESS = [
-    ('book', 'https://www.oreilly.com/.../9781492056348/'),
-    ('home', 'https://www.fluentpython.com/'),
-    ('1-20', 'https://www.fluentpython.com/'),
-    ('ora', 'https://www.oreilly.com/.../9781492056348/'),
-    ('2-10', 'http://example.com/'),
-    ('10-2', 'http://example.com/'),
-    ('22', 'http://firstshortened.co')
+    PathURL('book', 'https://www.oreilly.com/.../9781492056348/'),
+    PathURL('home', 'https://www.fluentpython.com/'),
+    PathURL('1-20', 'https://www.fluentpython.com/'),
+    PathURL('ora', 'https://www.oreilly.com/.../9781492056348/'),
+    PathURL('2-10', 'http://example.com/'),
+    PathURL('10-2', 'http://example.com/'),
+    PathURL('22', 'http://firstshortened.co'),
 ]
 
 # straightforward mapping of .htaccess; some targets may be duplicated.
@@ -60,7 +68,6 @@
 }
 
 
-
 def test_parse_htaccess():
     res = list(parse_htaccess(SAMPLE_HTACCESS))
     assert res == PARSED_SAMPLE_HTACCESS
@@ -83,8 +90,8 @@ def test_choose(a, b, expected):
 
 
 def test_load_redirects():
-   redirects, _ = load_redirects(PARSED_SAMPLE_HTACCESS)
-   assert redirects == SAMPLE_REDIRECTS
+    redirects, _ = load_redirects(PARSED_SAMPLE_HTACCESS)
+    assert redirects == SAMPLE_REDIRECTS
 
 
 def test_load_redirect_targets():
@@ -99,8 +106,8 @@ def test_load_redirect_targets():
         ('https://new.site/', '23', True),
     ],
 )
-def test_shorten(target, path, new):
-    expected = ShortenResult(target, path, new)
+def test_shorten_one(target, path, new):
+    expected = PathURL(path, target, new)
     redirects = dict(SAMPLE_REDIRECTS)
     targets = dict(SAMPLE_TARGETS)
     result = shorten_one(target, gen_unused_short(redirects), redirects, targets)
@@ -118,8 +125,23 @@ def test_shorten(target, path, new):
         assert targets == SAMPLE_TARGETS
 
 
+def test_timestamp():
+    with mock.patch('shortener.timestamp', return_value=FROZEN_TIME):
+        assert shortener.timestamp() == FROZEN_TIME
+
+
 def test_update_htaccess():
-    pass
+    directives = [
+        PathURL('home', 'https://www.fluentpython.com/', False),
+        PathURL('23', 'https://new.site/', True),
+        PathURL('24', 'https://other.new.site/', True)
+    ]
+    given = io.StringIO(SAMPLE_HTACCESS)
+    given.seek(0, io.SEEK_END)  # emulate append mode
+    with mock.patch('shortener.timestamp', return_value=FROZEN_TIME):
+        res = update_htaccess(given, directives)
+    assert res == 2
+    assert given.getvalue() == UPDATED_SAMPLE_HTACCESS
 
 
 def test_gen_short():